Barbell Medicine Podcast

Andrew Huberman’s new book, Protocols, says each of its routines “can work the first time, and every time,” and says of its lifting program, “I’ve seen it work for everyone I’ve suggested it to.” Wild! Dr. Feigenbaum read the book and pulled the studies it cites for the protocols that crossover with Barbell Medicine: training each muscle once a week to failure, cold plunges, pushing morning cortisol up with licorice root and grapefruit, drinking water on a schedule, an 11-supplement sleep stack, and nicotine pouches for focus.Dr. Baraki guesses what the book recommends before we get to what the cited studies found. In a few places the paper under the sentence says the opposite of the sentence. It should go without saying, nothing here is about Dr. Huberman personally. We’re rating what the book tells you to do.Timestamps00:00 Huberman’s Protocols and what it promises 01:23 Who this book is for, and how a book like this gets made 07:30 The games, and training each muscle once a week to failure 21:53 Cold plunge, dopamine, and brown fat 30:21 Cortisol: licorice root, grapefruit, and morning light 37:49 Drinking water before coffee 47:52 The 11-supplement sleep stack and CBT for insomnia 55:57 Nicotine pouches for focus 59:46 Lightning round: real line from the book or made up? 1:10:49 Final score and whether we’d give this book to our moms 1:12:57 What we’d recommend insteadResources:Where should my priorities be to improve my health? https://www.barbellmedicine.com/blog/where-should-my-priorities-be-to-improve-my-health/ Scott Carney’s audit of Protocols: https://sgcarney.substack.comNicotine Mystery Case- Episode 285: https://podcasts.apple.com/nz/podcast/episode-285-nicotine/id1199780143?i=1000651894798 Buy the book, Signal: https://www.barbellmedicine.com/shop/learning/signal/Free Vital 5 Action PlanNew Barbell Medicine Hybrid 5K and 10K Run + Lift ProgramsBaz-Valle E, Balsalobre-Fernández C, Alix-Fages C, Santos-Concejero J. A systematic review of the effects of different resistance training volumes on muscle hypertrophy. J Hum Kinet. 2022;81:199-210. doi:10.2478/hukin-2022-0017Pedersen H, Iversen VM, Vereide V, et al. High-frequency resistance training improves maximal lower-limb strength more than low frequency. Eur J Sport Sci. 2024;24(5):557-565. doi:10.1002/ejsc.12055Currier BS, D'Souza AC, Singh MAF, et al. American College of Sports Medicine position stand. Resistance training prescription for muscle function, hypertrophy, and physical performance in healthy adults: an overview of reviews. Med Sci Sports Exerc. 2026;58(4):851-872. doi:10.1249/MSS.0000000000003897Pelland JC, Remmert JF, Robinson ZP, Hinson SR, Zourdos MC. The resistance training dose response: meta-regressions exploring the effects of weekly volume and frequency on muscle hypertrophy and strength gains. Sports Med. 2026;56(2):481-505. doi:10.1007/s40279-025-02344-wRefalo MC, Helms ER, Trexler ET, Hamilton DL, Fyfe JJ. Influence of resistance training proximity-to-failure on skeletal muscle hypertrophy: a systematic review with meta-analysis. Sports Med. 2023;53(3):649-665. doi:10.1007/s40279-022-01784-yRobinson ZP, Pelland JC, Remmert JF, et al. Exploring the dose-response relationship between estimated resistance training proximity to failure, strength gain, and muscle hypertrophy: a series of meta-regressions. Sports Med. 2024;54(9):2209-2231. doi:10.1007/s40279-024-02069-2Isenmann E, Kaluza D, Havers T, et al. Resistance training alters body composition in middle-aged women depending on menopause: a 20-week control trial. BMC Womens Health. 2023;23(1):526. doi:10.1186/s12905-023-02671-yŠrámek P, Šimečková M, Janský L, Šavlíková J, Vybíral S. Human physiological responses to immersion into water of different temperatures. Eur J Appl Physiol. 2000;81(5):436-442. doi:10.1007/s004210050065Buijze GA, Sierevelt IN, van der Heijden BC, Dijkgraaf MG, Frings-Dresen MH. The effect of cold showering on health and work: a randomized controlled trial. PLoS One. 2016;11(9):e0161749. doi:10.1371/journal.pone.0161749Søberg S, Löfgren J, Philipsen FE, et al. Altered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming men. Cell Rep Med. 2021;2(10):100408. doi:10.1016/j.xcrm.2021.100408Cain T, Brinsley J, Bennett H, Nelson M, Maher C, Singh B. Effects of cold-water immersion on health and wellbeing: a systematic review and meta-analysis. PLoS One. 2025;20(1):e0317615. doi:10.1371/journal.pone.0317615Muzik O, Mangner TJ, Leonard WR, Kumar A, Janisse J, Granneman JG. 15O PET measurement of blood flow and oxygen consumption in cold-activated human brown fat. J Nucl Med. 2013;54(4):523-531. doi:10.2967/jnumed.112.111336Shattock MJ, Tipton MJ. 'Autonomic conflict': a different way to die during cold water immersion? J Physiol. 2012;590(14):3219-3230. doi:10.1113/jphysiol.2012.229864Grgic J. Effects of post-exercise cold-water immersion on resistance training-induced gains in muscular strength: a meta-analysis. Eur J Sport Sci. 2023;23(3):372-380. doi:10.1080/17461391.2022.2033851Leproult R, Colecchia EF, L'Hermite-Balériaux M, Van Cauter E. Transition from dim to bright light in the morning induces an immediate elevation of cortisol levels. J Clin Endocrinol Metab. 2001;86(1):151-157. doi:10.1210/jcem.86.1.7102Epstein MT, Espiner EA, Donald RA, Hughes H, Cowles RJ, Lun S. Licorice raises urinary cortisol in man. J Clin Endocrinol Metab. 1978;47(2):397-400. doi:10.1210/jcem-47-2-397Kageyama Y, Suzuki H, Saruta T. Glycyrrhizin induces mineralocorticoid activity through alterations in cortisol metabolism in the human kidney. J Endocrinol. 1992;135(1):147-152. doi:10.1677/joe.0.1350147Methlie P, Husebye EES, Hustad S, Lien EA, Løvås K. Grapefruit juice and licorice increase cortisol availability in patients with Addison's disease. Eur J Endocrinol. 2011;165(5):761-769. doi:10.1530/EJE-11-0518Sigurjónsdóttir HA, Franzson L, Manhem K, Ragnarsson J, Sigurdsson G, Wallerstedt S. Liquorice-induced rise in blood pressure: a linear dose-response relationship. J Hum Hypertens. 2001;15(8):549-552. doi:10.1038/sj.jhh.1001215Lilja JJ, Neuvonen M, Neuvonen PJ. Effects of regular consumption of grapefruit juice on the pharmacokinetics of simvastatin. Br J Clin Pharmacol. 2004;58(1):56-60. doi:10.1111/j.1365-2125.2004.02095.xChida Y, Steptoe A. Cortisol awakening response and psychosocial factors: a systematic review and meta-analysis. Biol Psychol. 2009;80(3):265-278. doi:10.1016/j.biopsycho.2008.10.004Vastbinder M, Kuindersma M, Mulder AH, Schuijt MP, Mudde AH. The influence of oral contraceptives on overnight 1 mg dexamethasone suppression test. Neth J Med. 2016;74(4):158-161.Johnston JG, Pollock DM. Circadian regulation of renal function. Free Radic Biol Med. 2018;119:93-107. doi:10.1016/j.freeradbiomed.2018.01.018Jordan J, Shannon JR, Black BK, et al. The pressor response to water drinking in humans: a sympathetic reflex? Circulation. 2000;101(5):504-509. doi:10.1161/01.cir.101.5.504Killer SC, Blannin AK, Jeukendrup AE. No evidence of dehydration with moderate daily coffee intake: a counterbalanced cross-over study in a free-living population. PLoS One. 2014;9(1):e84154. doi:10.1371/journal.pone.0084154Hakam N, Guzman Fuentes JL, Nabavizadeh B, et al. Outcomes in randomized clinical trials testing changes in daily water intake: a systematic review. JAMA Netw Open. 2024;7(11):e2447621. doi:10.1001/jamanetworkopen.2024.47621Altieri B, Aini I, Cannavale G, et al. Pathophysiology and treatment of exercise-associated hyponatremia. J Endocrinol Invest. 2026;49(1):1-10. doi:10.1007/s40618-025-02673-7Zick SM, Wright BD, Sen A, Arnedt JT. Preliminary examination of the efficacy and safety of a standardized chamomile extract for chronic primary insomnia: a randomized placebo-controlled pilot study. BMC Complement Altern Med. 2011;11:78. doi:10.1186/1472-6882-11-78Howatson G, Bell PG, Tallent J, Middleton B, McHugh MP, Ellis J. Effect of tart cherry juice (Prunus cerasus) on melatonin levels and enhanced sleep quality. Eur J Nutr. 2012;51(8):909-916. doi:10.1007/s00394-011-0263-7Pase MP, Himali JJ, Grima NA, et al. Sleep architecture and the risk of incident dementia in the community. Neurology. 2017;89(12):1244-1250. doi:10.1212/WNL.0000000000004373Qaseem A, Kansagara D, Forciea MA, Cooke M, Denberg TD; Clinical Guidelines Committee of the American College of Physicians. Management of chronic insomnia disorder in adults: a clinical practice guideline from the American College of Physicians. Ann Intern Med. 2016;165(2):125-133. doi:10.7326/M15-2175Trauer JM, Qian MY, Doyle JS, Rajaratnam SM, Cunnington D. Cognitive behavioral therapy for chronic insomnia: a systematic review and meta-analysis. Ann Intern Med. 2015;163(3):191-204. doi:10.7326/M14-2841Ferracioli-Oda E, Qawasmi A, Bloch MH. Meta-analysis: melatonin for the treatment of primary sleep disorders. PLoS One. 2013;8(5):e63773. doi:10.1371/journal.pone.0063773Burgess HJ, Revell VL, Molina TA, Eastman CI. Human phase response curves to three days of daily melatonin: 0.5 mg versus 3.0 mg. J Clin Endocrinol Metab. 2010;95(7):3325-3331. doi:10.1210/jc.2009-2590Erland LA, Saxena PK. Melatonin natural health products and supplements: presence of serotonin and significant variability of melatonin content. J Clin Sleep Med. 2017;13(2):275-281. doi:10.5664/jcsm.6462McCurry SM, Guthrie KA, Morin CM, et al. Telephone-based cognitive behavioral therapy for insomnia in perimenopausal and postmenopausal women with vasomotor symptoms: a MsFLASH randomized clinical trial. JAMA Intern Med. 2016;176(7):913-920. doi:10.1001/jamainternmed.2016.1795The 2022 hormone therapy position statement of The North American Menopause Society. Menopause. 2022;29(7):767-794. doi:10.1097/GME.0000000000002028Sun Q, Jin C. Cell signaling and epigenetic regulation of nicotine-induced carcinogenesis. Environ Pollut. 2024;345:123426. doi:10.1016/j.envpol.2024.123426Griesar WS, Zajdel DP, Oken BS. Nicotine effects on alertness and spatial attention in non-smokers. Nicotine Tob Res. 2002;4(2):185-194. doi:10.1080/14622200210123617Heishman SJ, Kleykamp BA, Singleton EG. Meta-analysis of the acute effects of nicotine and smoking on human performance. Psychopharmacology (Berl). 2010;210(4):453-469. doi:10.1007/s00213-010-1848-1DiFranza JR, Savageau JA, Rigotti NA, et al. Development of symptoms of tobacco dependence in youths: 30 month follow up data from the DANDY study. Tob Control. 2002;11(3):228-235. doi:10.1136/tc.11.3.228Travis N, Warner KE, Hartmann-Boyce J, et al. Oral nicotine pouches and public health: evidence from an updated scoping review. Nicotine Tob Res. Published online September 6, 2026. doi:10.1093/ntr/ntag203Antonio J, Peacock CA, Ellerbroek A, Fromhoff B, Silver T. The effects of consuming a high protein diet (4.4 g/kg/d) on body composition in resistance-trained individuals. J Int Soc Sports Nutr. 2014;11:19. doi:10.1186/1550-2783-11-19Delimaris I. Adverse effects associated with protein intake above the recommended dietary allowance for adults. ISRN Nutr. 2013;2013:126929. doi:10.5402/2013/126929Matta MK, Florian J, Zusterzeel R, et al. Effect of sunscreen application on plasma concentration of sunscreen active ingredients: a randomized clinical trial. JAMA. 2020;323(3):256-267. doi:10.1001/jama.2019.20747Ding D, Nguyen B, Nau T, et al. Daily steps and health outcomes in adults: a systematic review and dose-response meta-analysis. Lancet Public Health. 2025;10(8):e668-e681. doi:10.1016/S2468-2667(25)00164-1Engeroff T, Groneberg DA, Wilke J. After dinner rest a while, after supper walk a mile? A systematic review with meta-analysis on the acute postprandial glycemic response to exercise before and after meal ingestion in healthy subjects and patients with impaired glucose tolerance. Sports Med. 2023;53(4):849-869. doi:10.1007/s40279-022-01808-7Gulati M, Shaw LJ, Thisted RA, Black HR, Bairey Merz CN, Arnsdorf MF. Heart rate response to exercise stress testing in asymptomatic women: the St. James Women Take Heart Project. Circulation. 2010;122(2):130-137. doi:10.1161/CIRCULATIONAHA.110.93924Our Sponsors:* Check out Cometeer and use my code BBM for a great deal: https://www.cometeer.com* Check out Cometeer and use my code BBM for a great deal: https://www.cometeer.com* Check out FIGS and use my code FIGSRX for a great deal: https://wearfigs.com* Check out Factor and use my code factormeals.com/bbm50off for a great deal: https://www.factor75.com* Check out Quince and use my code BBM for a great deal: https://www.quince.comAdvertising Inquiries: https://redcircle.com/brands

A 22 year old soccer player with no symptoms walks into a clinic for a routine sports physical and walks out being told to quit his sport.Dr. Baraki takes this mystery case blind and we hand him the pieces one at a time: the EKG, the echocardiogram, the cardiac MRI, the Holter monitor, the treadmill test and the genetic panel. Half of them come back completely normal. Play along and commit to an answer before the reveal, because there is a point in this case where most people would change theirs.Then, the discussion about whether the restriction he was given was the right call, what the evidence on that says today compared with what it said for the previous 40 years, and why two doctors looking at the same numbers can reasonably land in different places.And then screening. Should an EKG should be mandatory for amateur athletes? All this and more, on this episode of the Barbell Medicine Podcast.Timestamps00:00 A 22-year-old needs a form signed02:16 The history and exam05:49 Reading his EKG 13:13 The echo and the MRI18:26 The rest of the workup, and Austin commits to a diagnosis24:02 Patient course27:54 What his care team decided29:45 How much the heart changes with training36:45 A second case that went differently41:52 Should a finding like this end a career45:47 Should an EKG be mandatory for amateur athletes55:59 What would actually move the needleResourcesBuy the book, Signal: https://www.barbellmedicine.com/shop/learning/signal/Free Vital 5 Action PlanNew Barbell Medicine Hybrid 5K and 10K Run + Lift ProgramsBarbell Medicine coaching and templates: https://www.barbellmedicine.comGet early access, ad-free listening, and exclusive content here: https://barbellmedicine.supercast.com/1. Marques JP, Freitas A, Abecasis J. Beware of regression of electrocardiographic abnormalities on detraining: it may not always mean "athlete's heart." Rev Port Cardiol (Engl Ed). 2021;40(10):801.e1-801.e6. doi:10.1016/j.repce.2021.10.012. PMID 34857120.2. Pelliccia A, Maron BJ, Culasso F, et al. Clinical significance of abnormal electrocardiographic patterns in trained athletes. Circulation. 2000;102(3):278-284. doi:10.1161/01.cir.102.3.278. PMID 10899089.3. Papadakis M, Carre F, Kervio G, et al. The prevalence, distribution, and clinical outcomes of electrocardiographic repolarization patterns in male athletes of African/Afro-Caribbean origin. Eur Heart J. 2011;32(18):2304-2313. doi:10.1093/eurheartj/ehr140. PMID 21613263.4. Schnell F, Riding N, O'Hanlon R, et al. Recognition and significance of pathological T-wave inversions in athletes. Circulation. 2015;131(2):165-173. doi:10.1161/CIRCULATIONAHA.114.011038. PMID 25583053.5. Olivotto I, Oreziak A, Barriales-Villa R, et al. Mavacamten for treatment of symptomatic obstructive hypertrophic cardiomyopathy (EXPLORER-HCM): a randomised, double-blind, placebo-controlled, phase 3 trial. Lancet. 2020;396(10253):759-769. doi:10.1016/S0140-6736(20)31792-X. PMID 32871100.6. Maron MS, Masri A, Nassif ME, et al. Aficamten for symptomatic obstructive hypertrophic cardiomyopathy. N Engl J Med. 2024;390(20):1849-1861. doi:10.1056/NEJMoa2401424. PMID 38739079.7. Myers J, Prakash M, Froelicher V, Do D, Partington S, Atwood JE. Exercise capacity and mortality among men referred for exercise testing. N Engl J Med. 2002;346(11):793-801. doi:10.1056/NEJMoa011858. PMID 11893790.8. Ommen SR, Mital S, Burke MA, et al. 2020 AHA/ACC guideline for the diagnosis and treatment of patients with hypertrophic cardiomyopathy: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation. 2020;142(25):e558-e631. doi:10.1161/CIR.0000000000000937. PMID 33215931.9. Lopes LR, Ho CY, Elliott PM. Genetics of hypertrophic cardiomyopathy: established and emerging implications for clinical practice. Eur Heart J. 2024;45(30):2727-2734. doi:10.1093/eurheartj/ehae421. PMID 38984491.10. Ingles J, Goldstein J, Thaxton C, et al. Evaluating the clinical validity of hypertrophic cardiomyopathy genes. Circ Genom Precis Med. 2019;12(2):e002460. doi:10.1161/CIRCGEN.119.002460. PMID 30681346.11. Pelliccia A, Maron BJ, Spataro A, Proschan MA, Spirito P. The upper limit of physiologic cardiac hypertrophy in highly trained elite athletes. N Engl J Med. 1991;324(5):295-301. doi:10.1056/NEJM199101313240504. PMID 1824720.12. Spirito P, Pelliccia A, Proschan MA, et al. Morphology of the "athlete's heart" assessed by echocardiography in 947 elite athletes representing 27 sports. Am J Cardiol. 1994;74(8):802-806. doi:10.1016/0002-9149(94)90439-1. PMID 7942554.13. Powers JM, Lim MY, Achebe MO, et al. American Society of Hematology 2026 guidelines for diagnosis of iron deficiency. Blood Adv. Published online August 24, 2026. doi:10.1182/bloodadvances.2025015950. PMID 42747316.14. Basavarajaiah S, Boraita A, Whyte G, et al. Ethnic differences in left ventricular remodeling in highly-trained athletes: relevance to differentiating physiologic left ventricular hypertrophy from hypertrophic cardiomyopathy. J Am Coll Cardiol. 2008;51(23):2256-2262. doi:10.1016/j.jacc.2007.12.061. PMID 18534273.15. Riding NR, Sharma S, McClean G, Adamuz C, Watt V, Wilson MG. Impact of geographical origin upon the electrical and structural manifestations of the black athlete's heart. Eur Heart J. 2019;40(1):50-58. doi:10.1093/eurheartj/ehy521. PMID 30169663.16. Kebed KY, Bos JM, Anavekar NS, Mulvagh SL, Ackerman MJ, Ommen SR. Hypertrophic cardiomyopathy, athlete's heart, or both: a case of hypertrophic cardiomyopathy regression. Circ Cardiovasc Imaging. 2015;8(7):e003312. doi:10.1161/CIRCIMAGING.115.003312. PMID 26162782.17. Pelliccia A, Maron BJ, De Luca R, Di Paolo FM, Spataro A, Culasso F. Remodeling of left ventricular hypertrophy in elite athletes after long-term deconditioning. Circulation. 2002;105(8):944-949. doi:10.1161/hc0802.104534. PMID 11864923.18. Ommen SR, Ho CY, Asif IM, et al. 2024 AHA/ACC/AMSSM/HRS/PACES/SCMR guideline for the management of hypertrophic cardiomyopathy: a report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines. Circulation. 2024;149(23):e1239-e1311. doi:10.1161/CIR.0000000000001250. PMID 38718139.19. Lampert R, Ackerman MJ, Marino BS, et al. Vigorous exercise in patients with hypertrophic cardiomyopathy. JAMA Cardiol. 2023;8(6):595-605. doi:10.1001/jamacardio.2023.1042. PMID 37195701.20. Pelliccia A, Caselli S, Pelliccia M, et al. Clinical outcomes in adult athletes with hypertrophic cardiomyopathy: a 7-year follow-up study. Br J Sports Med. 2020;54(16):1008-1012. doi:10.1136/bjsports-2019-100890. PMID 32532845.21. Kim JH, Baggish AL, Levine BD, et al. Clinical considerations for competitive sports participation for athletes with cardiovascular abnormalities: a scientific statement from the American Heart Association and American College of Cardiology. Circulation. 2025;151(11):e716-e761. doi:10.1161/CIR.0000000000001297. PMID 39973614.22. Corrado D, Basso C, Pavei A, Michieli P, Schiavon M, Thiene G. Trends in sudden cardiovascular death in young competitive athletes after implementation of a preparticipation screening program. JAMA. 2006;296(13):1593-1601. doi:10.1001/jama.296.13.1593. PMID 17018804.23. Harmon KG, Zigman M, Drezner JA. The effectiveness of screening history, physical exam, and ECG to detect potentially lethal cardiac disorders in athletes: a systematic review/meta-analysis. J Electrocardiol. 2015;48(3):329-338. doi:10.1016/j.jelectrocard.2015.02.001. PMID 25701104.24. Baggish AL, Hutter AM, Wang F, et al. Cardiovascular screening in college athletes with and without electrocardiography: a cross-sectional study. Ann Intern Med. 2010;152(5):269-275. doi:10.7326/0003-4819-152-5-201003020-00004. PMID 20194232.25. Drezner JA, Owens DS, Prutkin JM, et al. Electrocardiographic screening in National Collegiate Athletic Association athletes. Am J Cardiol. 2016;118(5):754-759. doi:10.1016/j.amjcard.2016.06.004. PMID 27496294.26. Williams EA, Pelto HF, Toresdahl BG, et al. Performance of the American Heart Association (AHA) 14-point evaluation versus electrocardiography for the cardiovascular screening of high school athletes: a prospective study. J Am Heart Assoc. 2019;8(14):e012235. doi:10.1161/JAHA.119.012235. PMID 31286819.27. Steinvil A, Chundadze T, Zeltser D, et al. Mandatory electrocardiographic screening of athletes to reduce their risk for sudden death: proven fact or wishful thinking? J Am Coll Cardiol. 2011;57(11):1291-1296. doi:10.1016/j.jacc.2010.10.037. PMID 21392644.28. Halkin A, Steinvil A, Rosso R, Adler A, Rozovski U, Viskin S. Preventing sudden death of athletes with electrocardiographic screening: what is the absolute benefit and how much will it cost? J Am Coll Cardiol. 2012;60(22):2271-2276. doi:10.1016/j.jacc.2012.09.003. PMID 23194938.29. Marijon E, Tafflet M, Celermajer DS, et al. Sports-related sudden death in the general population. Circulation. 2011;124(6):672-681. doi:10.1161/CIRCULATIONAHA.110.008979. PMID 21788587.30. Finocchiaro G, Papadakis M, Robertus JL, et al. Etiology of sudden death in sports: insights from a United Kingdom regional registry. J Am Coll Cardiol. 2016;67(18):2108-2115. doi:10.1016/j.jacc.2016.02.062. PMID 27151341.31. Harmon KG, Drezner JA, Maleszewski JJ, et al. Pathogeneses of sudden cardiac death in National Collegiate Athletic Association athletes. Circ Arrhythm Electrophysiol. 2014;7(2):198-204. doi:10.1161/CIRCEP.113.001376. PMID 24585715.32. Drezner JA, Rao AL, Heistand J, Bloomingdale MK, Harmon KG. Effectiveness of emergency response planning for sudden cardiac arrest in United States high schools with automated external defibrillators. Circulation. 2009;120(6):518-525. doi:10.1161/CIRCULATIONAHA.109.855890. PMID 19635968.33. Grubic N, Hill B, Phelan D, Baggish A, Dorian P, Johri AM. Bystander interventions and survival after exercise-related sudden cardiac arrest: a systematic review. Br J Sports Med. 2022;56(7):410-416. doi:10.1136/bjsports-2021-104623. PMID 34853034.Our Sponsors:* Check out Cometeer and use my code BBM for a great deal: https://www.cometeer.com* Check out Cometeer and use my code BBM for a great deal: https://www.cometeer.com* Check out FIGS and use my code FIGSRX for a great deal: https://wearfigs.com* Check out Factor and use my code factormeals.com/bbm50off for a great deal: https://www.factor75.com* Check out Quince and use my code BBM for a great deal: https://www.quince.comAdvertising Inquiries: https://redcircle.com/brands

A Halloween story about a man who does every wellness protocol, then an honest grading of each one. Dr. Jordan Feigenbaum tells the story of Dale Mercer, Unit 4471, who lives through a fully optimized Sunday in the year 2049: morning light panels, cold plunges, a 31-capsule supplement tray, grey-market peptides, methylene blue, an eccentric-only lifting machine, a protein IV timed to the anabolic window, sleep and readiness scores, a glucose sensor, mouth tape, Zone 2 with lactate pricks, and a 174-degree sauna.Then Jordan grades each one on a zero-to-five pumpkin scale. He covers what the studies actually tested, where the evidence is thin or tied to the companies selling the product, and the few places with real risk, like methylene blue with antidepressants and mouth taping with a blocked nose. The takeaway is plain: lift weights in a challenging way, do conditioning that improves your fitness, sleep enough, and eat a health-promoting diet in the right amount. Most of the rest is optional.The story is inspired by Rick Sieman's 1973 motorcycle magazine column "Sunday Morning Ride … 1984."Timestamps 00:00 WELLNESS ad 00:26 Sunday Morning Protocol 2049 11:23 Where this episode came from, and the pumpkin scale 12:45 Morning sunlight and cold plunges19:44 Supplements: magnesium, lion's mane, NAD, antler velvet, creatine 25:21 Peptides and methylene blue 30:27 Eccentric overload, slow tempo, and the anabolic window 34:40 Sleep trackers, HRV readiness scores, and CGMs 41:56 Mouth tape, Zone 2, and saunas 47:44 What actually worksResourcesBuy the book, Signal: https://www.barbellmedicine.com/shop/learning/signal/Free Vital 5 Action PlanNew Barbell Medicine Hybrid 5K and 10K Run + Lift ProgramsBarbell Medicine coaching and templates: https://www.barbellmedicine.comGet early access, ad-free listening, and exclusive content here: https://barbellmedicine.supercast.com/Creatine: Benefits, Side Effects & Safe Consumption: https://www.barbellmedicine.com/blog/what-is-creatine/Barbell Medicine Guide to Protein: https://www.barbellmedicine.com/blog/barbell-medicine-protein-recommendations/How to Measure, Use and Improve Your Heart Rate Variability: https://www.barbellmedicine.com/blog/heart-rate-variability-hrv/Burke TM, Markwald RR, Chinoy ED, et al. Combination of light and melatonin time cues for phase advancing the human circadian clock. Sleep. 2013;36(11):1617-1624. doi:10.5665/sleep.3110Auger RR, Burgess HJ, Emens JS, Deriy LV, Thomas SM, Sharkey KM. Clinical practice guideline for the treatment of intrinsic circadian rhythm sleep-wake disorders: advanced sleep-wake phase disorder (ASWPD), delayed sleep-wake phase disorder (DSWPD), non-24-hour sleep-wake rhythm disorder (N24SWD), and irregular sleep-wake rhythm disorder (ISWRD). An update for 2015: an American Academy of Sleep Medicine clinical practice guideline. J Clin Sleep Med. 2015;11(10):1199-1236. doi:10.5664/jcsm.5100van Maanen A, Meijer AM, van der Heijden KB, Oort FJ. The effects of light therapy on sleep problems: a systematic review and meta-analysis. Sleep Med Rev. 2016;29:52-62. doi:10.1016/j.smrv.2015.08.009Thompson A, Batterham AM, Jones H, Gregson W, Scott D, Atkinson G. The practicality and effectiveness of supplementary bright light for reducing jet-lag in elite female athletes. Int J Sports Med. 2013;34(7):582-589. doi:10.1055/s-0032-1331160Pjrek E, Friedrich ME, Cambioli L, et al. The efficacy of light therapy in the treatment of seasonal affective disorder: a meta-analysis of randomized controlled trials. Psychother Psychosom. 2020;89(1):17-24. doi:10.1159/000502891Burns AC, Saxena R, Vetter C, Phillips AJK, Lane JM, Cain SW. Time spent in outdoor light is associated with mood, sleep, and circadian rhythm-related outcomes: a cross-sectional and longitudinal study in over 400,000 UK Biobank participants. J Affect Disord. 2021;295:347-352. doi:10.1016/j.jad.2021.08.056Manson JE, Cook NR, Lee IM, et al. Vitamin D supplements and prevention of cancer and cardiovascular disease. N Engl J Med. 2019;380(1):33-44. doi:10.1056/NEJMoa1809944Srámek P, Simecková M, Janský L, Savlíková J, Vybíral S. Human physiological responses to immersion into water of different temperatures. Eur J Appl Physiol. 2000;81(5):436-442. doi:10.1007/s004210050065Cain T, Brinsley J, Bennett H, Nelson M, Maher C, Singh B. Effects of cold-water immersion on health and wellbeing: a systematic review and meta-analysis. PLoS One. 2025;20(1):e0317615. doi:10.1371/journal.pone.0317615Buijze GA, Sierevelt IN, van der Heijden BC, Dijkgraaf MG, Frings-Dresen MH. The effect of cold showering on health and work: a randomized controlled trial. PLoS One. 2016;11(9):e0161749. doi:10.1371/journal.pone.0161749Cameron BE, Steele J, Bradley WJ, et al. Post-exercise recovery methods: a systematic review and meta-analysis. SportRxiv. Preprint posted September 19, 2026. doi:10.51224/SportRxiv.1070Roberts LA, Raastad T, Markworth JF, et al. Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training. J Physiol. 2015;593(18):4285-4301. doi:10.1113/JP270570Piñero A, Burke R, Augustin F, et al. Throwing cold water on muscle growth: a systematic review with meta-analysis of the effects of postexercise cold water immersion on resistance training-induced hypertrophy. Eur J Sport Sci. 2024;24(2):177-189. doi:10.1002/ejsc.12074Liu G, Weinger JG, Lu ZL, Xue F, Sadeghpour S. Efficacy and safety of MMFS-01, a synapse density enhancer, for treating cognitive impairment in older adults: a randomized, double-blind, placebo-controlled trial. J Alzheimers Dis. 2016;49(4):971-990. doi:10.3233/JAD-150538Lopresti AL, Smith SJ. The effects of magnesium L-threonate (Magtein) on cognitive performance and sleep quality in adults: a randomised, double-blind, placebo-controlled trial. Front Nutr. 2025;12:1729164. doi:10.3389/fnut.2025.1729164Schuster J, Cycelskij I, Lopresti A, Hahn A. Magnesium bisglycinate supplementation in healthy adults reporting poor sleep: a randomized, placebo-controlled trial. Nat Sci Sleep. 2025;17:2027-2040. doi:10.2147/NSS.S524348Mah J, Pitre T. Oral magnesium supplementation for insomnia in older adults: a systematic review & meta-analysis. BMC Complement Med Ther. 2021;21(1):125. doi:10.1186/s12906-021-03297-zMori K, Inatomi S, Ouchi K, Azumi Y, Tuchida T. Improving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: a double-blind placebo-controlled clinical trial. Phytother Res. 2009;23(3):367-372. doi:10.1002/ptr.2634Surendran G, Saye J, Binti Mohd Jalil S, et al. Acute effects of a standardised extract of Hericium erinaceus (Lion’s Mane mushroom) on cognition and mood in healthy younger adults: a double-blind randomised placebo-controlled study. Front Nutr. 2025;12:1405796. doi:10.3389/fnut.2025.1405796Prokopidis K, Moriarty F, Bahat G, McLean J, Church DD, Patel HP. The effect of nicotinamide mononucleotide and riboside on skeletal muscle mass and function: a systematic review and meta-analysis. J Cachexia Sarcopenia Muscle. 2025;16(3):e13799. doi:10.1002/jcsm.13799Chen F, Zhou D, Kong AP, et al. Effects of nicotinamide mononucleotide on glucose and lipid metabolism in adults: a systematic review and meta-analysis of randomised controlled trials. Curr Diab Rep. 2024;25(1):4. doi:10.1007/s11892-024-01557-zBrakedal B, Skeie GO, Derad C, et al. Nicotinamide riboside for patients with early-stage Parkinson disease: the NOPARK randomized clinical trial. JAMA. Published online 2026. doi:10.1001/jama.2026.18828Sleivert G, Burke V, Palmer C, et al. The effects of deer antler velvet extract or powder supplementation on aerobic power, erythropoiesis, and muscular strength and endurance characteristics. Int J Sport Nutr Exerc Metab. 2003;13(3):251-265. doi:10.1123/ijsnem.13.3.251Syrotuik DG, MacFadyen KL, Harber VJ, Bell GJ. Effect of elk velvet antler supplementation on the hormonal response to acute and chronic exercise in male and female rowers. Int J Sport Nutr Exerc Metab. 2005;15(4):366-385. doi:10.1123/ijsnem.15.4.366Cox HD, Eichner D. Detection of human insulin-like growth factor-1 in deer antler velvet supplements. Rapid Commun Mass Spectrom. 2013;27(19):2170-2178. doi:10.1002/rcm.6678Delpino FM, Figueiredo LM, Forbes SC, Candow DG, Santos HO. Influence of age, sex, and type of exercise on the efficacy of creatine supplementation on lean body mass: a systematic review and meta-analysis of randomized clinical trials. Nutrition. 2022;103-104:111791. doi:10.1016/j.nut.2022.111791Prokopidis K, Giannos P, Triantafyllidis KK, Kechagias KS, Forbes SC, Candow DG. Effects of creatine supplementation on memory in healthy individuals: a systematic review and meta-analysis of randomized controlled trials. Nutr Rev. 2023;81(4):416-427. doi:10.1093/nutrit/nuac064Xu C, Bi S, Zhang W, Luo L. The effects of creatine supplementation on cognitive function in adults: a systematic review and meta-analysis. Front Nutr. 2024;11:1424972. doi:10.3389/fnut.2024.1424972Wilding JPH, Batterham RL, Calanna S, et al. Once-weekly semaglutide in adults with overweight or obesity. N Engl J Med. 2021;384(11):989-1002. doi:10.1056/NEJMoa2032183Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide once weekly for the treatment of obesity. N Engl J Med. 2022;387(3):205-216. doi:10.1056/NEJMoa2206038Poolton JT, Minett J, Kazmi A. Human evidence for BPC-157 in orthopaedic and regenerative medicine: a systematic review of efficacy and safety. Acta Orthop Belg. 2026;92(3). doi:10.52628/92.3.15837Reichel C, Gmeiner G, Thevis M. Detection of black market follistatin 344. Drug Test Anal. 2019;11(11-12):1675-1697. doi:10.1002/dta.2741ClinicalTrials.gov. Search results for BPC-157. National Library of Medicine. Accessed October 2026. https://clinicaltrials.gov/search?term=BPC-157Rodriguez P, Zhou W, Barrett DW, et al. Multimodal randomized functional MR imaging of the effects of methylene blue in the human brain. Radiology. 2016;281(2):516-526. doi:10.1148/radiol.2016152893US Food and Drug Administration. FDA Drug Safety Communication: updated information about the drug interaction between methylene blue (methylthioninium chloride) and serotonergic psychiatric medications. Updated October 20, 2011. https://www.fda.gov/drugs/drug-safety-and-availability/fda-drug-safety-communication-updated-information-about-drug-interaction-between-methylene-blueSchoenfeld BJ, Ogborn DI, Vigotsky AD, Franchi MV, Krieger JW. Hypertrophic effects of concentric vs. eccentric muscle actions: a systematic review and meta-analysis. J Strength Cond Res. 2017;31(9):2599-2608. doi:10.1519/JSC.0000000000001983Zhang X, Weakley J, Li H, Marcos-Frutos D, García-Ramos A. Acute and chronic effects of accentuated eccentric loading vs. constant-load resistance training: a systematic review and meta-analysis. Sports Med. 2026;56(7):1749-1770. doi:10.1007/s40279-026-02422-7Schoenfeld BJ, Aragon AA, Krieger JW. The effect of protein timing on muscle strength and hypertrophy: a meta-analysis. J Int Soc Sports Nutr. 2013;10(1):53. doi:10.1186/1550-2783-10-53Wirth J, Hillesheim E, Brennan L. The role of protein intake and its timing on body composition and muscle function in healthy adults: a systematic review and meta-analysis of randomized controlled trials. J Nutr. 2020;150(6):1443-1460. doi:10.1093/jn/nxaa049Schoenfeld BJ, Aragon AA. How much protein can the body use in a single meal for muscle-building? Implications for daily protein distribution. J Int Soc Sports Nutr. 2018;15:10. doi:10.1186/s12970-018-0215-1Morton RW, Murphy KT, McKellar SR, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med. 2018;52(6):376-384. doi:10.1136/bjsports-2017-097608Watson NF, Badr MS, Belenky G, et al. Recommended amount of sleep for a healthy adult: a joint consensus statement of the American Academy of Sleep Medicine and Sleep Research Society. Sleep. 2015;38(6):843-844. doi:10.5665/sleep.4716de Zambotti M, Goldstone A, Claudatos S, Colrain IM, Baker FC. A validation study of Fitbit Charge 2 compared with polysomnography in adults. Chronobiol Int. 2018;35(4):465-476. doi:10.1080/07420528.2017.1413578Baron KG, Abbott S, Jao N, Manalo N, Mullen R. Orthosomnia: are some patients taking the quantified self too far? J Clin Sleep Med. 2017;13(2):351-354. doi:10.5664/jcsm.6472Gavriloff D, Sheaves B, Juss A, Espie CA, Miller CB, Kyle SD. Sham sleep feedback delivered via actigraphy biases daytime symptom reports in people with insomnia: implications for insomnia disorder and wearable devices. J Sleep Res. 2018;27(6):e12726. doi:10.1111/jsr.12726Manresa-Rocamora A, Sarabia JM, Javaloyes A, Flatt AA, Moya-Ramón M. Heart rate variability-guided training for enhancing cardiac-vagal modulation, aerobic fitness, and endurance performance: a methodological systematic review with meta-analysis. Int J Environ Res Public Health. 2021;18(19):10299. doi:10.3390/ijerph181910299de Zambotti M, Forouzanfar M, Javitz H, et al. Impact of evening alcohol consumption on nocturnal autonomic and cardiovascular function in adult men and women: a dose-response laboratory investigation. Sleep. 2021;44(1):zsaa135. doi:10.1093/sleep/zsaa135Freckmann G, Hagenlocher S, Baumstark A, et al. Continuous glucose profiles in healthy subjects under everyday life conditions and after different meals. J Diabetes Sci Technol. 2007;1(5):695-703. doi:10.1177/193229680700100513Fox LA, Beck RW, Xing D. Variation of interstitial glucose measurements assessed by continuous glucose monitors in healthy, nondiabetic individuals. Diabetes Care. 2010;33(6):1297-1299. doi:10.2337/dc09-1971Dungan KM. 1,5-anhydroglucitol (GlycoMark) as a marker of short-term glycemic control and glycemic excursions. Expert Rev Mol Diagn. 2008;8(1):9-19. doi:10.1586/14737159.8.1.9Kira S, Ito C, Fujikawa R, Misumi M. Association between a biomarker of glucose spikes, 1,5-anhydroglucitol, and cancer mortality. BMJ Open Diabetes Res Care. 2020;8(1):e001607. doi:10.1136/bmjdrc-2020-001607Rebholz CM, Grams ME, Chen Y, et al. Serum levels of 1,5-anhydroglucitol and risk of incident end-stage renal disease. Am J Epidemiol. 2017;186(8):952-960. doi:10.1093/aje/kwx167Ikeda N, Hiroi Y. Cardiovascular disease and 1,5-anhydro-d-glucitol. Glob Health Med. 2019;1(2):83-87. doi:10.35772/ghm.2019.01031Thabit H, Leelarathna L, Wilinska ME, et al. Accuracy of continuous glucose monitoring during three closed-loop home studies under free-living conditions. Diabetes Technol Ther. 2015;17(11):801-807. doi:10.1089/dia.2015.0062Berry SE, Valdes AM, Drew DA, et al. Human postprandial responses to food and potential for precision nutrition. Nat Med. 2020;26(6):964-973. doi:10.1038/s41591-020-0934-0Richardson KM, Jospe MR, Bohlen LC, Crawshaw J, Saleh AA, Schembre SM. The efficacy of using continuous glucose monitoring as a behaviour change tool in populations with and without diabetes: a systematic review and meta-analysis of randomised controlled trials. Int J Behav Nutr Phys Act. 2024;21(1):145. doi:10.1186/s12966-024-01692-6Makkena HB, Nimmagadda Y, Boinapelly N, et al. Behavioral and psychosocial effects of participant-visible continuous glucose monitoring in adults without diabetes: a systematic review. Medicina (Kaunas). 2026;62(9). doi:10.3390/medicina62091814Guerrero-Romero F, Simental-Mendía LE, González-Ortiz M, et al. The product of triglycerides and glucose, a simple measure of insulin sensitivity. Comparison with the euglycemic-hyperinsulinemic clamp. J Clin Endocrinol Metab. 2010;95(7):3347-3351. doi:10.1210/jc.2010-0288Rhee J, Iansavitchene A, Mannala S, Graham ME, Rotenberg B. Breaking social media fads and uncovering the safety and efficacy of mouth taping in patients with mouth breathing, sleep disordered breathing, or obstructive sleep apnea: a systematic review. PLoS One. 2025;20(5):e0323643. doi:10.1371/journal.pone.0323643Lee YC, Lu CT, Cheng WN, Li HY. The impact of mouth-taping in mouth-breathers with mild obstructive sleep apnea: a preliminary study. Healthcare (Basel). 2022;10(9):1755. doi:10.3390/healthcare10091755Cooper S, Oborne J, Harrison T, Tattersfield A. Effect of mouth taping at night on asthma control: a randomised single-blind crossover study. Respir Med. 2009;103(6):813-819. doi:10.1016/j.rmed.2009.02.003Alshehri NA, Alsaif NF, Abdulrazaq AN, Jabor RM, Al-Sayed AA. Impact of nasal obstruction and mouth taping on sleep apnea indicators: systematic review and meta-analysis. OTO Open. 2026;10(3):e70294. doi:10.1002/oto2.70294Yang H, Huyett P, Wang TY, et al. Mouth closure and airflow in patients with obstructive sleep apnea: a nonrandomized clinical trial. JAMA Otolaryngol Head Neck Surg. 2024;150(11):1012-1019. doi:10.1001/jamaoto.2024.3319Storoschuk KL, Moran-MacDonald A, Gibala MJ, Gurd BJ. Much ado about zone 2: a narrative review assessing the efficacy of zone 2 training for improving mitochondrial capacity and cardiorespiratory fitness in the general population. Sports Med. 2025;55(7):1611-1624. doi:10.1007/s40279-025-02261-ySitko S, Artetxe X, Bonnevie-Svendsen M, et al. What is “zone 2 training”?: experts’ viewpoint on definition, training methods, and expected adaptations. Int J Sports Physiol Perform. 2025;20(11):1614-1617. doi:10.1123/ijspp.2024-0303Faude O, Kindermann W, Meyer T. Lactate threshold concepts: how valid are they? Sports Med. 2009;39(6):469-490. doi:10.2165/00007256-200939060-00003Foster C, Porcari JP, Anderson J, et al. The talk test as a marker of exercise training intensity. J Cardiopulm Rehabil Prev. 2008;28(1):24-30. doi:10.1097/01.HCR.0000311504.41775.78Laukkanen T, Khan H, Zaccardi F, Laukkanen JA. Association between sauna bathing and fatal cardiovascular and all-cause mortality events. JAMA Intern Med. 2015;175(4):542-548. doi:10.1001/jamainternmed.2014.8187Kivimäki M, Virtanen M, Ferrie JE. The link between sauna bathing and mortality may be noncausal. JAMA Intern Med. 2015;175(10):1718. doi:10.1001/jamainternmed.2015.3426Epstein Y, Shoenfeld Y. The link between sauna bathing and mortality may be noncausal. JAMA Intern Med. 2015;175(10):1718-1719. doi:10.1001/jamainternmed.2015.3429Hamaya R, Joyama Y, Miyata T, et al. Non-acute effects of passive heating interventions on cardiometabolic risk and vascular health: systematic review and meta-analysis of randomized controlled trials. Am J Prev Cardiol. 2025;23:101082. doi:10.1016/j.ajpc.2025.101082Debray A, Gravel H, Garceau L, et al. Finnish sauna bathing and vascular health of adults with coronary artery disease: a randomized controlled trial. J Appl Physiol (1985). 2023;135(4):795-804. doi:10.1152/japplphysiol.00322.2023Our Sponsors:* Check out Cometeer and use my code BBM for a great deal: https://www.cometeer.com* Check out Cometeer and use my code BBM for a great deal: https://www.cometeer.com* Check out FIGS and use my code FIGSRX for a great deal: https://wearfigs.com* Check out Factor and use my code factormeals.com/bbm50off for a great deal: https://www.factor75.com* Check out Quince and use my code BBM for a great deal: https://www.quince.comAdvertising Inquiries: https://redcircle.com/brands

How much cardio should you do, and does more of it ever become harmful? Cardiorespiratory fitness keeps improving with training load and nobody has found a ceiling. Getting fitter keeps lowering mortality risk as far out as anyone has measured. The one dose dependent harm that survives scrutiny is atrial fibrillation, and it shows up around six to seven hours a week of hard endurance training sustained for years.This episode goes through the Danish jogging study behind the “fast running is as deadly as sitting on the couch” headlines and why two deaths in forty people can’t carry it, the much larger datasets that found no harm signal, and what changes when somebody measures fitness on a treadmill instead of asking people about minutes. Then atrial fibrillation, coronary calcium and heart scarring in lifelong endurance athletes, the sudden cardiac arrest numbers from 29 million race finishers, whether cardio interferes with lifting, fuel handling, weight loss and metabolic compensation, and bone density in cyclists. It closes with a rewritten version of the cardio guidelines, including volume, intensity, progression, and the fitness and health targets the real guidelines leave out.Timestamps00:00 The jogging J-curve and the headlines02:42 The Danish study, its confidence interval, and what a MET measures08:02 Better measurement: 15 check-ins and fitness on a treadmill12:51 Atrial fibrillation: the dose, the mechanism, and stroke risk22:06 Coronary calcium and heart scarring in masters athletes25:58 The marathon death story and cardiac arrest rates29:08 How much training it takes to keep getting fitter34:12 Does cardio interfere with your lifting gains39:52 Flux, the athlete's paradox, and liver fat44:12 Cardio, weight loss, and metabolic compensation51:13 Bone density in cyclists and energy availability57:51 Writing the cardio guidelinesResourcesBuy the book, Signal: https://www.barbellmedicine.com/shop/learning/signal/Free Vital 5 Action PlanNew Barbell Medicine Hybrid 5K and 10K Run + Lift ProgramsBarbell Medicine coaching and templates: https://www.barbellmedicine.comGet early access, ad-free listening, and exclusive content here: https://barbellmedicine.supercast.com/1. Schnohr P, O'Keefe JH, Marott JL, Lange P, Jensen GB. Dose of jogging and long-term mortality: the Copenhagen City Heart Study. J Am Coll Cardiol. 2015. doi:10.1016/j.jacc.2014.11.0232. Arem H, Moore SC, Patel A, et al. Leisure time physical activity and mortality: a detailed pooled analysis of the dose-response relationship. JAMA Intern Med. 2015. doi:10.1001/jamainternmed.2015.05333. Lee DH, Rezende LFM, Joh HK, et al. Long-term leisure-time physical activity intensity and all-cause and cause-specific mortality: a prospective cohort of US adults. Circulation. 2022. doi:10.1161/CIRCULATIONAHA.121.0581624. Mandsager K, Harb S, Cremer P, Phelan D, Nissen SE, Jaber W. Association of cardiorespiratory fitness with long-term mortality among adults undergoing exercise treadmill testing. JAMA Netw Open. 2018. doi:10.1001/jamanetworkopen.2018.36055. Ekelund U, Tarp J, Steene-Johannessen J, et al. Dose-response associations between accelerometry measured physical activity and sedentary time and all cause mortality: systematic review and harmonised meta-analysis. BMJ. 2019. doi:10.1136/bmj.l45706. Saulicz A, Abernethy D, Wraith D. Can too much exercise kill you? A systematic review of the risk of a cardiovascular event or death from long term strenuous exercise. Eur J Epidemiol. 2026. doi:10.1007/s10654-025-01353-37. Morganroth J, Maron BJ, Henry WL, Epstein SE. Comparative left ventricular dimensions in trained athletes. Ann Intern Med. 1975.8. Davies CL, Pallikadavath S, March DS, et al. Physical activity, atrial fibrillation and the dose-response relationship: a systematic review and meta-analysis. Eur J Prev Cardiol. 2026. doi:10.1093/eurjpc/zwag5359. Molina L, Mont L, Marrugat J, et al. Long-term endurance sport practice increases the incidence of lone atrial fibrillation in men: a follow-up study. Europace. 2008. doi:10.1093/europace/eun07110. Javed W, Botis I, Tomoaia R, et al. Clinical and cardiovascular magnetic resonance characteristics of veteran male endurance athletes with atrial fibrillation: VENTOUX-AF. J Am Heart Assoc. 2025. doi:10.1161/JAHA.125.04230811. Liu B, Pagan E, Beccarino N, Chang D, Dulmovits E, Beldner S. Voltage mapping and pulmonary vein isolation in master athletes with atrial fibrillation. Pacing Clin Electrophysiol. 2022;45(11):1338-1342. doi:10.1111/pace.1460212. Guasch E, Benito B, Qi X, et al. Atrial fibrillation promotion by endurance exercise: demonstration and mechanistic exploration in an animal model. J Am Coll Cardiol. 2013. doi:10.1016/j.jacc.2013.01.09113. Flannery MD, Canovas R, Janssens K, et al. Atrial fibrillation in former world-class rowers: role of environmental and genetic factors. Eur Heart J. 2025. doi:10.1093/eurheartj/ehaf36914. Johansen KR, Ranhoff AH, Sorensen E, et al. Risk of atrial fibrillation and stroke among older men exposed to prolonged endurance sport practice: a 10-year follow-up. The Birkebeiner Ageing Study and the Tromso Study. Open Heart. 2022;9(2). doi:10.1136/openhrt-2022-00215415. Apelland T, Letnes JM, Janssens K, et al. Arrhythmia burden, symptoms and quality of life in female and male endurance athletes with paroxysmal atrial fibrillation: a multicentre cohort study in Norway, Australia and Belgium. BMJ Open. 2025;15(8):e100496. doi:10.1136/bmjopen-2025-10049616. Merghani A, Maestrini V, Rosmini S, et al. Prevalence of subclinical coronary artery disease in masters endurance athletes with a low atherosclerotic risk profile. Circulation. 2017;136(2):126-137. doi:10.1161/CIRCULATIONAHA.116.02696417. Aengevaeren VL, Mosterd A, Braber TL, et al. Relationship between lifelong exercise volume and coronary atherosclerosis in athletes. Circulation. 2017;136(2):138-148. doi:10.1161/CIRCULATIONAHA.117.02783418. Kim JH, Rim AJ, Miller JT, et al. Cardiac arrest during long-distance running races. JAMA. 2025;333(19):1699-1707. doi:10.1001/jama.2025.302619. Montero D, Cathomen A, Jacobs RA, et al. Haematological rather than skeletal muscle adaptations contribute to the increase in peak oxygen uptake induced by moderate endurance training. J Physiol. 2015;593(20):4677-4688. doi:10.1113/JP27025020. Molmen KS, Almquist NW, Skattebo O. Effects of exercise training on mitochondrial and capillary growth in human skeletal muscle: a systematic review and meta-regression. Sports Med. 2025;55(1):115-144. doi:10.1007/s40279-024-02120-221. Church TS, Earnest CP, Skinner JS, Blair SN. Effects of different doses of physical activity on cardiorespiratory fitness among sedentary, overweight or obese postmenopausal women with elevated blood pressure: a randomized controlled trial. JAMA. 2007.22. Hickson RC. Interference of strength development by simultaneously training for strength and endurance. Eur J Appl Physiol Occup Physiol. 1980.23. Schumann M, Feuerbacher JF, Sunkeler M, et al. Compatibility of concurrent aerobic and strength training for skeletal muscle size and function: an updated systematic review and meta-analysis. Sports Med. 2022. doi:10.1007/s40279-021-01587-724. Lundberg TR, Feuerbacher JF, Sunkeler M, Schumann M. The effects of concurrent aerobic and strength training on muscle fiber hypertrophy: a systematic review and meta-analysis. Sports Med. 2022;52(10):2391-2403. doi:10.1007/s40279-022-01688-x25. Feuerbacher JF, Jacobs MW, Heumann P, Pareja-Blanco F, Hackney AC, Zacher J, Schumann M. Neuromuscular adaptations to same versus separate muscle-group concurrent aerobic and strength training in recreationally active males and females. Scand J Med Sci Sports. 2025;35(2):e70025. doi:10.1111/sms.7002526. Montero D, Lundby C. Refuting the myth of non-response to exercise training: 'non-responders' do respond to higher dose of training. J Physiol. 2017. doi:10.1113/JP27348027. Mezincescu AM, Rudd A, Cheyne L, et al. Comparison of intramyocellular lipid metabolism in patients with diabetes and male athletes. Nat Commun. 2024;15(1):3690. doi:10.1038/s41467-024-47843-y28. Keating SE, Hackett DA, Parker HM, et al. Effect of aerobic exercise training dose on liver fat and visceral adiposity. J Hepatol. 2015;63(1):174-182. doi:10.1016/j.jhep.2015.02.02229. Pearson RC, Cogan B, Garcia SA, Jenkins NT. Effect of prior exercise on postprandial lipemia: an updated meta-analysis and systematic review. Int J Sport Nutr Exerc Metab. 2022;32(6):501-518. doi:10.1123/ijsnem.2022-004330. Ross R, Hudson R, Stotz PJ, Lam M. Effects of exercise amount and intensity on abdominal obesity and glucose tolerance in obese adults: a randomized trial. Ann Intern Med. 2015. doi:10.7326/M14-118931. Westerterp KR, Meijer GA, Janssen EM, Saris WH, ten Hoor F. Long-term effect of physical activity on energy balance and body composition. Br J Nutr. 1992.32. Pontzer H, Trexler ET. The evidence for constrained total energy expenditure in humans and other animals. Curr Biol. 2026;36(4):1013-1025.e4. doi:10.1016/j.cub.2026.01.02533. Nichols JF, Palmer JE, Levy SS. Low bone mineral density in highly trained male master cyclists. Osteoporos Int. 2003;14(8):644-649.34. Nichols JF, Rauh MJ. Longitudinal changes in bone mineral density in male master cyclists and nonathletes. J Strength Cond Res. 2011;25(3):727-734. doi:10.1519/JSC.0b013e3181c6a11635. Olmedillas H, Gonzalez-Aguero A, Moreno LA, Casajus JA, Vicente-Rodriguez G. Cycling and bone health: a systematic review. BMC Med. 2012;10:168. doi:10.1186/1741-7015-10-16836. Abrahin O, Rodrigues RP, Marcal AC, Alves EA, Figueiredo RC, de Sousa EC. Swimming and cycling do not cause positive effects on bone mineral density: a systematic review. Rev Bras Reumatol. 2016. doi:10.1016/j.rbre.2016.02.01337. Keay N, Francis G, Hind K. Low energy availability assessed by a sport-specific questionnaire and clinical interview indicative of bone health, endocrine profile and cycling performance in competitive male cyclists. BMJ Open Sport Exerc Med. 2018;4(1):e000424. doi:10.1136/bmjsem-2018-00042438. Keay N, Francis G, Entwistle I, Hind K. Clinical evaluation of education relating to nutrition and skeletal loading in competitive male road cyclists at risk of relative energy deficiency in sports (RED-S): 6-month randomised controlled trial. BMJ Open Sport Exerc Med. 2019;5(1):e000523. doi:10.1136/bmjsem-2019-00052339. Heikura IA, McCluskey WTP, Tsai MC, et al. Application of the IOC Relative Energy Deficiency in Sport (REDs) Clinical Assessment Tool version 2 (CAT2) across 200+ elite athletes. Br J Sports Med. 2024;59(1):24-35. doi:10.1136/bjsports-2024-10812140. Kim JH, Malhotra R, Chiampas G, et al. Cardiac arrest during long-distance running races. N Engl J Med. 2012. doi:10.1056/NEJMoa110646841. Areta JL, Meehan E, Howe G, Redman LM. Energetics of a world-tour female road cyclist during a multistage race (Tour de France Femmes). Int J Sport Nutr Exerc Metab. 2024;34(5):253-257. doi:10.1123/ijsnem.2023-027542. Saris WH, van Erp-Baart MA, Brouns F, Westerterp KR, ten Hoor F. Study on food intake and energy expenditure during extreme sustained exercise: the Tour de France. Int J Sports Med. 1989;10(suppl 1):S26-S31.Our Sponsors:* Check out Cometeer and use my code BBM for a great deal: https://www.cometeer.com* Check out Cometeer and use my code BBM for a great deal: https://www.cometeer.com* Check out FIGS and use my code FIGSRX for a great deal: https://wearfigs.com* Check out Factor and use my code factormeals.com/bbm50off for a great deal: https://www.factor75.com* Check out Quince and use my code BBM for a great deal: https://www.quince.comAdvertising Inquiries: https://redcircle.com/brands

How much resistance training do you actually need, and is there a point where more stops helping? We trace the "lift weights twice a week" recommendation back to the 1989 study it came from, which found that three days beat two, and to the citation loop that turned it into a guideline anyway. Then we go through the evidence on whether lifting is dangerous, including the heart, injury rates, and the J-shaped mortality curve, and work out where the dose-response actually saturates for strength, muscle mass, bone mineral density, and how your body handles fuel.The short answer is that almost every number in this literature marks where a benefit starts, and very little of it goes far enough to show where a benefit stops. We finish by writing the resistance training guideline the way we think it should be written, with target outcomes, a training dose, and testable targets.Timestamps 00:00 Where the "lift weights twice a week" rule came from 04:18 What actually counts as resistance training 06:56 Does lifting make your heart wall thicker 15:34 Anabolic steroids and the heart 19:16 Injury rates and cardiac arrest at the gym 22:03 How the lifting J-curve got made 28:05 ACSM audits its own recommendation 31:11 Strength: where the plateau actually sits 35:49 Why grip strength can't answer this 41:43 Muscle mass versus muscle function 44:50 Bone, and the turkey wing that settled the dose 49:50 Fuel handling, insulin sensitivity, and the clock 1:00:46 The 2018 guidelines, and how I would write themResourcesBuy the book, Signal: https://www.barbellmedicine.com/shop/learning/signal/New Barbell Medicine Hybrid 5K and 10K Run + Lift ProgramsBarbell Medicine coaching and templates: https://www.barbellmedicine.comGet early access, ad-free listening, and exclusive content here: https://barbellmedicine.supercast.com/Braith RW, Graves JE, Pollock ML, Leggett SL, Carpenter DM, Colvin AB. Comparison of 2 vs 3 days/week of variable resistance training during 10- and 18-week programs. Int J Sports Med. 1989;10(6):450-454. doi:10.1055/s-2007-1024942. PMID 2628366.American College of Sports Medicine. Position stand: the recommended quantity and quality of exercise for developing and maintaining cardiorespiratory and muscular fitness in healthy adults. Med Sci Sports Exerc. 1990;22(2):265-274. PMID 2355825.Sandercock GRH, Moran J, Cohen DD. Who is meeting the strengthening physical activity guidelines by definition: a cross-sectional study of 253,423 English adults? PLoS One. 2022;17(5):e0267277. doi:10.1371/journal.pone.0267277. PMID 35507575.Shakespear-Druery J, De Cocker K, Biddle SJH, Gasevic D, Bennie JA. Assessment of muscle-strengthening exercise in public health surveillance for adults: a systematic review. Prev Med. 2021;148:106566. doi:10.1016/j.ypmed.2021.106566. PMID 33878352.Zhang Y, Lee DH, Rezende LFM, et al. Long-term resistance training with all-cause and cause-specific mortality: assessing dose-response and joint associations with aerobic physical activity. Br J Sports Med. 2026;60(12):874-883. doi:10.1136/bjsports-2025-110503. PMID 42230125.Morganroth J, Maron BJ, Henry WL, Epstein SE. Comparative left ventricular dimensions in trained athletes. Ann Intern Med. 1975;82(4):521-524. doi:10.7326/0003-4819-82-4-521. PMID 1119766.Naylor LH, George K, O'Driscoll G, Green DJ. The athlete's heart: a contemporary appraisal of the Morganroth hypothesis. Sports Med. 2008;38(1):69-90. doi:10.2165/00007256-200838010-00006. PMID 18081368.Myerson SG, Montgomery HE, World MJ, Pennell DJ. Left ventricular mass: reliability of M-mode and 2-dimensional echocardiographic formulas. Hypertension. 2002;40(5):673-678. doi:10.1161/01.hyp.0000036401.99908.db. PMID 12411461.Pelliccia A, Maron BJ, Spataro A, Proschan MA, Spirito P. The upper limit of physiologic cardiac hypertrophy in highly trained elite athletes. N Engl J Med. 1991;324(5):295-301. doi:10.1056/NEJM199101313240504. PMID 1824720.Spirito P, Pelliccia A, Proschan MA, et al. Morphology of the "athlete's heart" assessed by echocardiography in 947 elite athletes representing 27 sports. Am J Cardiol. 1994;74(8):802-806. doi:10.1016/0002-9149(94)90439-1. PMID 7942554.Pelliccia A, Spataro A, Caselli G, Maron BJ. Absence of left ventricular wall thickening in athletes engaged in intense power training. Am J Cardiol. 1993;72(14):1048-1054. doi:10.1016/0002-9149(93)90861-6. PMID 8213586.Spence AL, Naylor LH, Carter HH, et al. A prospective randomised longitudinal MRI study of left ventricular adaptation to endurance and resistance exercise training in humans. J Physiol. 2011;589(Pt 22):5443-5452. doi:10.1113/jphysiol.2011.217125. PMID 21969450.Utomi V, Oxborough D, Whyte GP, et al. Systematic review and meta-analysis of training mode, imaging modality and body size influences on the morphology and function of the male athlete's heart. Heart. 2013;99(23):1727-1733. doi:10.1136/heartjnl-2012-303465. PMID 23474689.Smit DL, Voogel AJ, den Heijer M, de Ronde W. Anabolic androgenic steroids induce reversible left ventricular hypertrophy and cardiac dysfunction: echocardiography results of the HAARLEM study. Front Reprod Health. 2021;3:732318. doi:10.3389/frph.2021.732318. PMID 36304014.Abdullah R, Bjørnebekk A, Hauger LE, Hullstein IR, Edvardsen T, Haugaa KH, Almaas VM. Severe biventricular cardiomyopathy in both current and former long-term users of anabolic-androgenic steroids. Eur J Prev Cardiol. 2024;31(5):599-608. doi:10.1093/eurjpc/zwad362. PMID 37992194.Keogh JWL, Winwood PW. The epidemiology of injuries across the weight-training sports. Sports Med. 2017;47(3):479-501. doi:10.1007/s40279-016-0575-0. PMID 27328853.Aasa U, Svartholm I, Andersson F, Berglund L. Injuries among weightlifters and powerlifters: a systematic review. Br J Sports Med. 2017;51(4):211-219. doi:10.1136/bjsports-2016-096037. PMID 27707741.Page RL, Husain S, White LY, et al. Cardiac arrest at exercise facilities: implications for placement of automated external defibrillators. J Am Coll Cardiol. 2013;62(22):2102-2109. doi:10.1016/j.jacc.2013.06.048. PMID 23933539.Hollings M, Mavros Y, Freeston J, Fiatarone Singh M. The effect of progressive resistance training on aerobic fitness and strength in adults with coronary heart disease: a systematic review and meta-analysis of randomised controlled trials. Eur J Prev Cardiol. 2017;24(12):1242-1259. doi:10.1177/2047487317713329.Momma H, Kawakami R, Honda T, Sawada SS. Muscle-strengthening activities are associated with lower risk and mortality in major non-communicable diseases: a systematic review and meta-analysis of cohort studies. Br J Sports Med. 2022;56(13):755-763. doi:10.1136/bjsports-2021-105061. PMID 35228201.O'Keefe JH, O'Keefe EL, Eckert R, Lavie CJ. Training strategies to optimize cardiovascular durability and life expectancy. Mo Med. 2023;120(2):155-162. PMID 37091937. PMCID PMC10121111.Currier BS, McLeod JC, Banfield L, et al. American College of Sports Medicine position stand: resistance training prescription for muscle function, hypertrophy, and physical performance in healthy adults: an overview of reviews. Med Sci Sports Exerc. 2026;58(4):851-872. PMID 41843416.Ralston GW, Kilgore L, Wyatt FB, Buchan D, Baker JS. Weekly training frequency effects on strength gain: a meta-analysis. Sports Med Open. 2018;4(1):36. doi:10.1186/s40798-018-0149-9. PMID 30076500.Pelland JC, Remmert JF, Robinson ZP, Hinson SR, Zourdos MC. The resistance training dose response: meta-regressions exploring the effects of weekly volume and frequency on muscle hypertrophy and strength gains. Sports Med. 2026;56(2):481-505. doi:10.1007/s40279-025-02344-w. PMID 41343037.Ortega FB, Silventoinen K, Tynelius P, Rasmussen F. Muscular strength in male adolescents and premature death: cohort study of one million participants. BMJ. 2012;345:e7279. doi:10.1136/bmj.e7279. PMID 23144234.Ruiz JR, Sui X, Lobelo F, et al. Association between muscular strength and mortality in men: prospective cohort study. BMJ. 2008;337:a439. doi:10.1136/bmj.a439. PMID 18595904.Timpka S, Petersson IF, Zhou C, Englund M. Muscle strength in adolescent men and risk of cardiovascular disease events and mortality in middle age. BMC Med. 2014;12:62. doi:10.1186/1741-7015-12-62. PMID 24731728.Leong DP, Teo KK, Rangarajan S, et al. Prognostic value of grip strength: findings from the Prospective Urban Rural Epidemiology (PURE) study. Lancet. 2015;386(9990):266-273. doi:10.1016/S0140-6736(14)62000-6. PMID 25982160.Tieland M, Verdijk LB, de Groot LCPGM, van Loon LJC. Handgrip strength does not represent an appropriate measure to evaluate changes in muscle strength during an exercise intervention program in frail older people. Int J Sport Nutr Exerc Metab. 2015;25(1):27-36. doi:10.1123/ijsnem.2013-0123. PMID 24903908.Grgic J, Garofolini A, Orazem J, Sabol F, Schoenfeld BJ, Pedisic Z. Effects of resistance training on muscle size and strength in very elderly adults: a systematic review and meta-analysis of randomized controlled trials. Sports Med. 2020;50(11):1983-1999. doi:10.1007/s40279-020-01331-7. PMID 32740889.Huebner M, Riemann B, Hatchett A. Grip strength and sports performance in competitive master weightlifters. Int J Environ Res Public Health. 2023;20(3):2033. doi:10.3390/ijerph20032033. PMID 36767396.López-Bueno R, Andersen LL, Koyanagi A, et al. Thresholds of handgrip strength for all-cause, cancer, and cardiovascular mortality: a systematic review with dose-response meta-analysis. Ageing Res Rev. 2022;82:101778. doi:10.1016/j.arr.2022.101778.MacDonald HV, Johnson BT, Huedo-Medina TB, et al. Dynamic resistance training as stand-alone antihypertensive lifestyle therapy: a meta-analysis. J Am Heart Assoc. 2016;5(10):e003231. doi:10.1161/JAHA.116.003231. PMID 27680663.Bhasin S, Travison TG, Manini TM, et al. Sarcopenia definition: the position statements of the Sarcopenia Definition and Outcomes Consortium. J Am Geriatr Soc. 2020;68(7):1410-1418. doi:10.1111/jgs.16372. PMID 32150289.Cawthon PM, Manini T, Patel SM, et al. Putative cut-points in sarcopenia components and incident adverse health outcomes: an SDOC analysis. J Am Geriatr Soc. 2020;68(7):1429-1437. doi:10.1111/jgs.16517. PMID 32633824.Rubin CT, Lanyon LE. Regulation of bone formation by applied dynamic loads. J Bone Joint Surg Am. 1984;66(3):397-402. PMID 6699056.Rubin CT, Lanyon LE. Regulation of bone mass by mechanical strain magnitude. Calcif Tissue Int. 1985;37(4):411-417. doi:10.1007/BF02553711. PMID 3930039.Zhao R, Zhang M, Zhang Q. The effects of differing resistance training modes on the preservation of bone mineral density in postmenopausal women: a meta-analysis. Osteoporos Int. 2015;26(5):1605-1618. PMID 25603795.Watson SL, Weeks BK, Weis LJ, Harding AT, Horan SA, Beck BR. High-intensity resistance and impact training improves bone mineral density and physical function in postmenopausal women with osteopenia and osteoporosis: the LIFTMOR randomized controlled trial. J Bone Miner Res. 2018;33(2):211-220. doi:10.1002/jbmr.3284.Reid IR, Horne AM, Mihov B, et al. Fracture prevention with zoledronate in older women with osteopenia. N Engl J Med. 2018;379(25):2407-2416. doi:10.1056/NEJMoa1808082. PMID 30575489.Muniyappa R, Lee S, Chen H, Quon MJ. Current approaches for assessing insulin sensitivity and resistance in vivo: advantages, limitations, and appropriate usage. Am J Physiol Endocrinol Metab. 2008;294(1):E15-E26. PMID 17957034.Koopman R, Manders RJF, Jonkers RAM, Hul GBJ, Kuipers H, van Loon LJC. Intramyocellular lipid and glycogen content are reduced following resistance exercise in untrained healthy males. Eur J Appl Physiol. 2006;96(5):525-534. doi:10.1007/s00421-006-0139-3. PMID 16369816.Goodpaster BH, He J, Watkins S, Kelley DE. Skeletal muscle lipid content and insulin resistance: evidence for a paradox in endurance-trained athletes. J Clin Endocrinol Metab. 2001;86(12):5755-5761. doi:10.1210/jcem.86.12.8075. PMID 11739435.van Loon LJC, Goodpaster BH. Increased intramuscular lipid storage in the insulin-resistant and endurance-trained state. Pflugers Arch. 2005;451(5):606-616. doi:10.1007/s00424-005-1509-0. PMID 16155759.Richter EA, Mikines KJ, Galbo H, Kiens B. Effect of exercise on insulin action in human skeletal muscle. J Appl Physiol. 1989;66(2):876-885. PMID 2496078.Holten MK, Zacho M, Gaster M, Juel C, Wojtaszewski JFP, Dela F. Strength training increases insulin-mediated glucose uptake, GLUT4 content, and insulin signaling in skeletal muscle in patients with type 2 diabetes. Diabetes. 2004;53(2):294-305. PMID 14747278.Mikines KJ, Sonne B, Tronier B, Galbo H. Effects of acute exercise and detraining on insulin action in trained men. J Appl Physiol. 1989;66(2):704-711. PMID 2496077.Kjøbsted R, Wojtaszewski JFP, Treebak JT. Role of AMP-activated protein kinase for regulating post-exercise insulin sensitivity. Experientia Suppl. 2016;107:81-126. doi:10.1007/978-3-319-43589-3_4. PMID 27812978.Bird SR, Hawley JA. Update on the effects of physical activity on insulin sensitivity in humans. BMJ Open Sport Exerc Med. 2017;2(1):e000143. doi:10.1136/bmjsem-2016-000143. PMID 28879026.Iaccarino G, Franco D, Sorriento D, Strisciuglio T, Barbato E, Morisco C. Modulation of insulin sensitivity by exercise training: implications for cardiovascular prevention. J Cardiovasc Transl Res. 2021;14(2):256-270. doi:10.1007/s12265-020-10057-w. PMID 32737757.Hingst, Janne R et al. “Insulin Sensitization Following a Single Exercise Bout Is Uncoupled to Glycogen in Human Skeletal Muscle: A Meta-analysis of 13 Single-Center Human Studies.” Diabetes vol. 71,11 (2022): 2237-2250. doi:10.2337/db22-0015Gillen JB, Estafanos S, Williamson E, et al. Interrupting prolonged sitting with repeated chair stands or short walks reduces postprandial insulinemia in healthy adults. J Appl Physiol. 2020;130(1):104-113. doi:10.1152/japplphysiol.00796.2020. PMID 33180640.Francois ME, Baldi JC, Manning PJ, et al. "Exercise snacks" before meals: a novel strategy to improve glycaemic control in individuals with insulin resistance. Diabetologia. 2014;57(7):1437-1445. doi:10.1007/s00125-014-3244-6. PMID 24817675.US Department of Health and Human Services. Physical Activity Guidelines for Americans. 2nd ed. USDHHS; 2018.Our Sponsors:* Check out Cometeer and use my code BBM for a great deal: https://www.cometeer.com* Check out Cometeer and use my code BBM for a great deal: https://www.cometeer.com* Check out FIGS and use my code FIGSRX for a great deal: https://wearfigs.com* Check out Factor and use my code factormeals.com/bbm50off for a great deal: https://www.factor75.com* Check out Quince and use my code BBM for a great deal: https://www.quince.comAdvertising Inquiries: https://redcircle.com/brands

Nearly every warning you've heard about lifting weights was written down before anybody checked it. We trace where those warnings came from, starting with a Harvard student in 1854 and ending with a curve on a graph that's being used today to argue you can lift too much.Along the way: the men who built themselves with barbells and then sold the public five-pound dumbbells, because iron was expensive to mail and a booklet cost pennies. The muscle-bound myth, which nobody could define when a graduate student surveyed 45 physiologists about it. The 1961 report that took the deep squat out of every branch of the American military, measured with a device its author built himself and never validated. The claim that lifting stunts a child's growth, which no professional body ever actually made. And the argument women got, which was never about injury at all.Timestamps:0:00 Intro2:33 2,500 years of people picking up heavy things7:24 George Windship and the Health Lift10:56 Blaikie's truck horse and the muscle-bound myth14:59 Bernarr Macfadden19:39 Charles Atlas and Dynamic Tension27:01 Carl Klein, a homemade device, and the parallel squat30:57 Thomas Delorme and three sets of ten35:20 Kids, growth plates, and where the stunting idea came from41:43 Women, "you'll get bulky," and Dudley Sargent in 191250:05 Pregnancy, from 1949 to a 2025 barbell study53:40 The pattern, and the curve on next week's graphResources:Buy the book, Signal: https://www.barbellmedicine.com/shop/learning/signal/New Barbell Medicine Hybrid 5K and 10K Run + Lift ProgramsBarbell Medicine coaching and templates: https://www.barbellmedicine.com1. Downs DS, Chasan-Taber L, Evenson KR, Leiferman J, Yeo S. Physical activity and pregnancy: past and present evidence and future recommendations. Res Q Exerc Sport. 2012;83(4):485-502. doi:10.1080/02701367.2012.10599138. PMID 23367811.2. McMurray RG, Mottola MF, Wolfe LA, Artal R, Millar L, Pivarnik JM. Recent advances in understanding maternal and fetal responses to exercise. Med Sci Sports Exerc. 1993;25(12):1305-1321. PMID 8107536.3. Smith KM, Campbell CG. Physical activity during pregnancy: impact of applying different physical activity guidelines. J Pregnancy. 2013;2013:165617. doi:10.1155/2013/165617. PMID 23476778.4. American College of Obstetricians and Gynecologists. Physical activity and exercise during pregnancy and the postpartum period. ACOG Committee Opinion No. 804. Obstet Gynecol. 2020;135(4):e178-e188. doi:10.1097/AOG.0000000000003772. PMID 32217980.5. American Academy of Pediatrics Committee on Sports Medicine and Fitness. Strength training by children and adolescents. Pediatrics. 2001;107(6):1470-1472. doi:10.1542/peds.107.6.1470. PMID 11389279.6. Stricker PR, Faigenbaum AD, McCambridge TM; Council on Sports Medicine and Fitness. Resistance training for children and adolescents. Pediatrics. 2020;145(6):e20201011. doi:10.1542/peds.2020-1011. PMID 32457216.7. Gardiner EN. Athletics of the Ancient World. Clarendon Press; 1930:54. See also Gardiner EN. Olympia: Its History and Remains. Clarendon Press; 1925.8. Heffernan C. The Bybon stone and ancient strength. Physical Culture Study. 2021. Accessed September 2026. https://physicalculturestudy.com.9. Pausanias. Description of Greece. 6.14.5. Jones WHS, trans. Loeb Classical Library. Harvard University Press.10. Quintilian. Institutio Oratoria. 1.9.5. Butler HE, trans. Loeb Classical Library. Harvard University Press.11. Heffernan C. Milo of Croton and the invention of progressive overload. Physical Culture Study. 2026. Accessed September 2026. https://physicalculturestudy.com. See also H.J. Lutcher Stark Center for Physical Culture and Sports, University of Texas at Austin, Milo Bar-Bell Company holdings.12. Liddell HG, Scott R. A Greek-English Lexicon. 9th ed. Clarendon Press; entry γυμνάσιον. Thucydides. History of the Peloponnesian War. 1.6. Crawley R, trans.13. Tomlinson RA. Gymnasium. In: Oxford Classical Dictionary. Oxford University Press; 2015. doi:10.1093/acrefore/9780199381135.013.2963. See also Stavrou D. The Greek Gymnasium [thesis]. University of Leicester; 2016:38.14. Xenophon. Constitution of the Lacedaimonians. 1.4. Marchant EC, trans. Loeb Classical Library. Harvard University Press.15. Plutarch. Life of Lycurgus. 14. Perrin B, trans. Loeb Classical Library. Harvard University Press.16. Ollier F. Le Mirage Spartiate. Vols 1-2. Boccard; 1933-1943. Discussed in Rahe PA. The Grand Strategy of Classical Sparta. Yale University Press; 2016. See also Christesen P. Utopia on the Eurotas: Economic Aspects of the Spartan Mirage. In: Powell A, Hodkinson S, eds. Sparta: The Body Politic. Classical Press of Wales; 2010.17. Pausanias. Description of Greece. 5.16. Jones WHS, trans. Loeb Classical Library. Harvard University Press.18. Scarborough J. Galen and the gladiators. Episteme. 1971;5:98-111.19. Tipton CM. The history of "Exercise Is Medicine" in ancient civilizations. Adv Physiol Educ. 2014;38(2):109-117. doi:10.1152/advan.00136.2013. PMCID PMC4056176.20. Vegetius FR. De Re Militari (The Military Institutions of the Romans). Book I. Clarke J, trans. 1767.21. Surviving halteres: a catalogue. EXARC Journal. 2017;(3). Accessed September 2026. https://exarc.net.22. Talaga M. Physical culture in the Middle Ages: revisiting the disappearance thesis. Cogent Arts Humanit. 2025. doi:10.1080/23311983.2025.2482388.23. Rawcliffe C. Health and the environment in the medieval hospital. History. 2022. doi:10.1111/1468-229X.13238.24. Elyot T. The Boke Named the Governour. 1531. Croft HHS, ed. Kegan Paul; 1883:171.25. Campillo P, Caballero D. Girolamo Mercuriale and the art of gymnastics. Hektoen International. 2020. Accessed September 2026. https://hekint.org.26. Todd T. The myth of the muscle-bound lifter. NSCA J. 1985;7(3):37-41. Citing Van Doren C. Benjamin Franklin. Viking Press; 1938.27. Galen. Exhortation to the Study of the Arts (Protrepticus). Chapters 9-14. Walsh J, trans. Medical Life. 1930;37:507-529. See also Xenophontos S. Galen's Exhortation to the Study of Medicine. In: Bouras-Vallianatos P, Xenophontos S, eds. Greek Medical Literature and Its Readers. Routledge; 2018:67-93.28. Todd J. "Strength is Health": George Barker Windship and the first American weight training boom. Iron Game History. 1993;3(1):3-14. https://starkcenter.org/igh/igh-v3/igh-v3-n1/igh0301c.pdf.29. Windship GB. Autobiographical sketches of a strength-seeker. Atlantic Monthly. 1862;9(51):102-115.30. US Patent 46,413. Improvement in graduated dumb-bells. GB Windship, Boston. Granted 14 February 1865.31. Savage DF. US Patent 28,505. 1860.32. The Health-Lift Reduced to a Science: Cumulative Exercise, A Thorough Gymnastic System in Ten Minutes Once a Day. New York: Health-Lift Company; 1875.33. Blaikie W. How to Get Strong and How to Stay So. New York: Harper & Brothers; 1879:99-100.34. Bryant D. William Blaikie and physical fitness in late nineteenth century America. Iron Game History. 1992;2(3):3.35. Sandow E. Sandow on Physical Training. Adam GM, ed. 1894:12, 23, 207.36. Sandow E. Strength and How to Obtain It. London: Gale & Polden; 1897:34, Table 7.37. Sandow E. Strength and How to Obtain It. Revised ed. London: Gale & Polden; [c1899]. Project Gutenberg ebook 65987.38. Todd J, Todd T. Requiem for a strongman: reassessing the career of Professor Louis Attila. Iron Game History. 2002;7(2-3):42-55.39. Pall Mall Gazette. December 1889. Clipping in Attila's scrapbook, Todd-McLean Collection, H.J. Lutcher Stark Center, University of Texas at Austin.40. Chapman D. Sandow's first triumph. Iron Game History. 1994;3(3):3-8.41. Robert Hoffman Business Papers finding aid. H.J. Lutcher Stark Center for Physical Culture and Sports, University of Texas at Austin.42. Hall DT, Fair JD. The pioneers of protein. Iron Game History. 2004;8(3):26-28.43. Shurley J, Todd J. Joe Weider, All American Athlete, and the promotion of strength training for sport: 1940-1969. Iron Game History. 2012;12(1):9-12.44. Todd J. Bernarr Macfadden: reformer of feminine form. Iron Game History. 1991;1(4-5):3-8.45. Yagoda B. The true story of Bernarr Macfadden. American Heritage. 1981;33(1):22-28.46. Murtha R, Heffernan C, Hunt T. Building American supermen? Bernarr MacFadden, Benito Mussolini and American fascism in the 1930s. Sport in Society. 2020. doi:10.1080/17430437.2020.1865313.47. New York Times. 6 October 1905:10; 10 October 1905:9.48. Macfadden B. Macfadden's Encyclopedia of Physical Culture. New York: Physical Culture Publishing; 1912:847. Quoted in Todd T, NSCA J. 1985;7(3):37-41.49. Danna S. Charles Atlas: muscle man. Iron Game History. 1996;4(4):3-6, 12-14. https://starkcenter.org/igh/igh-v4/igh-v4-n4/igh0404c.pdf.50. Guide to the Charles Atlas Records, NMAH.AC.0654. Archives Center, National Museum of American History, Smithsonian Institution.51. Charles Atlas course text, undated later edition.52. Charles P. Roman: a gloriously healthy life. Chief Marketer.53. Kannenberg G Jr. The ad that made an icon out of Mac. Hogan's Alley. 1999;2(3).54. Michigan State University Libraries comic art index, Charles Atlas advertisements. https://comics.lib.msu.edu/rri/arri/atlas.htm.55. Charles Atlas. Encyclopedia.com.56. Todd J, Todd T. The conversion of Dr. Peter Karpovich. Iron Game History. 2005;8(4):4-12. https://starkcenter.org/igh/igh-v8/igh-v8-n4/igh0804c.pdf.57. Murray J, Karpovich P. Weight Training in Athletics. Englewood Cliffs, NJ: Prentice-Hall; 1956.58. Murray J. John Carrol Grimek: the nonpareil. Iron Game History. 1994;3(3):10-12.59. Zorbas WS, Karpovich PV. The effect of weight lifting upon the speed of muscular contractions. Res Q. 1951;22(2):145-148.60. Klein KK. The deep squat exercise as utilized in weight training for athletes and its effect on the ligaments of the knee. J Assoc Phys Ment Rehabil. 1961;15(1):6-11, 23.61. Sports Illustrated. Coverage of Klein's knee-ligament findings. 1962.62. Todd T. Karl Klein and the squat. NSCA J. 1984;6(3):26-31.63. Chandler TJ, Wilson GD, Stone MH. The effect of the squat exercise on knee stability. Med Sci Sports Exerc. 1989;21(3):299-303. PMID 2733579.64. Panariello RA, Backus SI, Parker JW. The effect of the squat exercise on anterior-posterior knee translation in professional football players. Am J Sports Med. 1994;22(6):768-773. doi:10.1177/036354659402200607. PMID 7856800.65. Berryman JW. Exercise is medicine: a historical perspective. Curr Sports Med Rep. 2010;9(4):195-201. doi:10.1249/JSR.0b013e3181e7d86d.66. Todd JS, Shurley JP, Todd TC. Thomas L. DeLorme and the science of progressive resistance exercise. J Strength Cond Res. 2012;26(11):2913-2923. doi:10.1519/JSC.0b013e31825adcb4.67. Kraus H, Hirschland RP. Minimum muscular fitness tests in school children. Res Q. 1954;25(2):178-188. doi:10.1080/10671188.1954.10624957.68. The President's Council on Youth Fitness. Exhibit. H.J. Lutcher Stark Center for Physical Culture and Sports, University of Texas at Austin. Accessed September 2026.69. Bonnie Prudden: biography. Bonnie Prudden Foundation. Accessed September 2026. https://bonnieprudden.com.70. Executive Order 10673: Fitness of American Youth. 21 Fed Reg 5341. July 16, 1956.71. Heady JA, Morris JN, Kagan A, Raffle PAB. Coronary heart disease in London busmen: a progress report with particular reference to physique. Br J Prev Soc Med. 1961;15(4):143-153.72. US Department of Health and Human Services. Physical Activity and Health: A Report of the Surgeon General. Chapter 2. Centers for Disease Control and Prevention; 1996.73. American College of Sports Medicine. Position stand: the recommended quantity and quality of exercise for developing and maintaining cardiorespiratory and muscular fitness in healthy adults. Med Sci Sports Exerc. 1990;22(2):265-274. PMID 2355825.74. Brady TA, Cahill BR, Bodnar LM. Weight training-related injuries in the high school athlete. Am J Sports Med. 1982;10(1):1-5. doi:10.1177/036354658201000101. PMID 6459035.75. Dahab KS, McCambridge TM. Strength training in children and adolescents: raising the bar for young athletes? Sports Health. 2009;1(3):223-226. doi:10.1177/1941738109334215. PMID 23015875.76. American Academy of Pediatrics Committee on Sports Medicine. Weight training and weight lifting: information for the pediatrician. Physician Sportsmed. 1983;11(3):157-161.77. American Academy of Pediatrics Committee on Sports Medicine. Strength training, weight and power lifting, and body building by children and adolescents. Pediatrics. 1990;86(5):801-803.78. Smith NJ, Stanitski CL. Sports Medicine: A Practical Guide. Philadelphia, PA: WB Saunders; 1987:33.79. Stricker PR, Faigenbaum AD, McCambridge TM; American Academy of Pediatrics Council on Sports Medicine and Fitness. Resistance training for children and adolescents. Pediatrics. 2020;145(6):e20201011. doi:10.1542/peds.2020-1011.80. Faigenbaum AD. Youth resistance training. President's Council on Physical Fitness and Sports Research Digest. 2003;4(3):1-8.81. Kato S, Ishiko T. Obstructed growth of children's bones due to excessive labor in remote corners. In: Kato K, ed. Proceedings of the International Congress of Sport Sciences. Tokyo, Japan: Japanese Union of Sport Sciences; 1964:476.82. Rowe PH. Colles fracture due to weightlifting. Br J Sports Med. 1979;13(3):130-131. doi:10.1136/bjsm.13.3.130. PMID 486885.83. Ryan JR, Salciccioli GG. Fractures of the distal radial epiphysis in adolescent weight lifters. Am J Sports Med. 1976;4(1):26-27. doi:10.1177/036354657600400105.84. Benton JW. Epiphyseal fracture in sports. Physician Sportsmed. 1982;10(11):63-71.85. Gumbs VL, Segal D, Halligan JB, Lower G. Bilateral distal radius and ulnar fractures in adolescent weight lifters. Am J Sports Med. 1982;10(6):375-379. doi:10.1177/036354658201000612.86. Jenkins NH, Mintowt-Czyz WJ. Bilateral fracture separations of the distal radial epiphyses during weight-lifting. Br J Sports Med. 1986;20(2):72-73. doi:10.1136/bjsm.20.2.72.87. Weiss AC, Sponseller PD. Salter-Harris type I fracture of the distal radius due to weightlifting. Orthop Rev. 1989;18(3):233-235.88. Browne TD. Bilateral wrist fractures in an adolescent weightlifter. Orthopedics. 1990.89. Faigenbaum AD, Myer GD. Resistance training among young athletes: safety, efficacy and injury prevention effects. Br J Sports Med. 2010;44(1):56-63. doi:10.1136/bjsm.2009.068098.90. Sadres E, Eliakim A, Constantini N, Lidor R, Falk B. The effect of long-term resistance training on anthropometric measures, muscle strength, and self concept in pre-pubertal boys. Pediatr Exerc Sci. 2001;13(4):357-372. doi:10.1123/pes.13.4.357.91. Malina RM. Weight training in youth: growth, maturation, and safety: an evidence-based review. Clin J Sport Med. 2006;16(6):478-487. doi:10.1097/01.jsm.0000248843.31874.be.92. Lloyd RS, Faigenbaum AD, Stone MH, et al. Position statement on youth resistance training: the 2014 international consensus. Br J Sports Med. 2014;48(7):498-505. doi:10.1136/bjsports-2013-092952.93. American Academy of Pediatrics Council on Sports Medicine and Fitness. Strength training by children and adolescents. Pediatrics. 2008;121(4):835-840. doi:10.1542/peds.2007-3790. PMID 18381549.94. Faigenbaum AD, Kraemer WJ, Blimkie CJR, et al. Youth resistance training: updated position statement paper from the National Strength and Conditioning Association. J Strength Cond Res. 2009;23(5 Suppl):S60-S79. doi:10.1519/JSC.0b013e31819df407. PMID 19620931.95. Milone MT, Bernstein J, Freedman KB, Tjoumakaris F. There is no need to avoid resistance training (weight lifting) until physeal closure. Phys Sportsmed. 2013;41(4):101-105. doi:10.3810/psm.2013.11.2040. PMID 24393806.96. Fiatarone MA, Marks EC, Ryan ND, Meredith CN, Lipsitz LA, Evans WJ. High-intensity strength training in nonagenarians: effects on skeletal muscle. JAMA. 1990;263(22):3029-3034. PMID 2342214.97. Fiatarone MA, O'Neill EF, Ryan ND, et al. Exercise training and nutritional supplementation for physical frailty in very elderly people. N Engl J Med. 1994;330(25):1769-1775. doi:10.1056/NEJM199406233302501. PMID 8190152.98. Sargent DA. Are athletics making girls masculine? A practical answer to a question every girl asks. 1912.99. Jones A. Weight-training for women. In: Nautilus Bulletin No. 2. Ch. 15. DeLand, FL: Nautilus Sports/Medical Industries; [c1971]. http://www.arthurjonesexercise.com/Bulletin2/15.PDF.100. Cureton KJ, Collins MA, Hill DW, McElhannon FM. Muscle hypertrophy in men and women. Med Sci Sports Exerc. 1988;20(4):338-344. PMID 3173042.101. Hubal MJ, Gordish-Dressman H, Thompson PD, et al. Variability in muscle size and strength gain after unilateral resistance training. Med Sci Sports Exerc. 2005;37(6):964-972. PMID 15947721.102. Roberts BM, Nuckols G, Krieger JW. Sex differences in resistance training: a systematic review and meta-analysis. J Strength Cond Res. 2020;34(5):1448-1460. doi:10.1519/JSC.0000000000003521. PMID 32218059.103. Refalo MC, Nuckols G, Galpin AJ, Gallagher IJ, Hamilton DL, Fyfe JJ. Sex differences in absolute and relative changes in muscle size following resistance training in healthy adults: a systematic review with Bayesian meta-analysis. PeerJ. 2025;13:e19042. doi:10.7717/peerj.19042. PMID 40028215.104. Handelsman DJ, Hirschberg AL, Bermon S. Circulating testosterone as the hormonal basis of sex differences in athletic performance. Endocr Rev. 2018;39(5):803-829. doi:10.1210/er.2018-00020. PMID 30010735.105. Bhasin S, Storer TW, Berman N, et al. The effects of supraphysiologic doses of testosterone on muscle size and strength in normal men. N Engl J Med. 1996;335(1):1-7. doi:10.1056/NEJM199607043350101. PMID 8637535.106. Huang G, Basaria S, Travison TG, et al. Testosterone dose-response relationships in hysterectomized women with or without oophorectomy. Menopause. 2014;21(6):612-623. doi:10.1097/GME.0000000000000093. PMID 24281237.107. Franke WW, Berendonk B. Hormonal doping and androgenization of athletes: a secret program of the German Democratic Republic government. Clin Chem. 1997;43(7):1262-1279. PMID 9216474.108. OpenPowerlifting database analysis of tested versus untested totals.109. Average player heights, National Basketball Association and Women's National Basketball Association, against US adult means from the National Health and Nutrition Examination Survey anthropometric reference data.110. History of women's weightlifting. International Weightlifting Federation. Accessed September 2026. https://iwf.sport.111. Adamfi A, IWF Director General, on the pre-1983 IWF constitution. Inside the Games. Accessed September 2026. https://www.insidethegames.biz.112. History of women's powerlifting. International Powerlifting Federation. Accessed September 2026. https://www.powerlifting.sport.113. Holloway JB, Gater D, Ritchie M, et al. Strength training for female athletes: a position paper. Part I. NSCA J. 1989;11(4):43-51. Part II. NSCA J. 1989;11(5):29-36.114. Kehler AK, Heinrich KM. A selective review of prenatal exercise guidelines since the 1950s until present: written for women, health care professionals, and female athletes. Women Birth. 2015;28(4):e93-e98. doi:10.1016/j.wombi.2015.07.004. PMID 26210535.115. Berghella V, Saccone G. Exercise in pregnancy! Am J Obstet Gynecol. 2017;216(4):335-337. doi:10.1016/j.ajog.2017.01.023.116. Davenport MH, Ruchat SM, Poitras VJ, et al. Prenatal exercise for the prevention of gestational diabetes mellitus and hypertensive disorders of pregnancy: a systematic review and meta-analysis. Br J Sports Med. 2018;52(21):1367-1375. doi:10.1136/bjsports-2018-099355. PMID 30337463.117. Prevett C, Gingerich J, Sivak A, Davenport MH. Impact of resistance training on maternal and fetal outcomes: a systematic review and meta-analysis. Br J Sports Med. 2025;59(17):1173-1183. doi:10.1136/bjsports-2025-109626. PMID 40610191.118. Moolyk AN, Wowdzia JB, Matenchuk BA, et al. Acute fetal response to high-intensity resistance training in pregnancy. Br J Sports Med. 2025;59(3):159-167. doi:10.1136/bjsports-2024-108569. PMID 39694629.119. Momma H, Kawakami R, Honda T, Sawada SS. Muscle-strengthening activities are associated with lower risk and mortality in major non-communicable diseases: a systematic review and meta-analysis of cohort studies. Br J Sports Med. 2022;56(13):755-763. doi:10.1136/bjsports-2021-105061.120. Bennie JA, Lee DC, Khan A, et al. Muscle-strengthening exercise among 397,423 U.S. adults: prevalence, correlates, and associations with health conditions. Am J Prev Med. 2018;55(6):864-874. doi:10.1016/j.amepre.2018.07.022. PMID 30458949.Our Sponsors:* Check out Cometeer and use my code BBM for a great deal: https://www.cometeer.com* Check out Cometeer and use my code BBM for a great deal: https://www.cometeer.com* Check out FIGS and use my code FIGSRX for a great deal: https://wearfigs.com* Check out Factor and use my code factormeals.com/bbm50off for a great deal: https://www.factor75.com* Check out Quince and use my code BBM for a great deal: https://www.quince.comAdvertising Inquiries: https://redcircle.com/brands

Parts of the country now get a few weeks of wildfire smoke every year, and the obvious question is whether there is a point where the air is bad enough that the workout costs you more than it gives you. We went and looked. There is a real number, it comes from about 1.5 million people, and it is not the number that gets quoted.This is a free preview of Direct Line, our monthly ask-us-anything for Barbell Medicine Plus subscribers. Two of this month's twelve questions are here in full.First: training in wildfire smoke. What PM2.5 is, why the AQI on your phone and the number in the paper are not the same quantity, where the 90-minutes-at-100-micrograms figure comes from and why it is softer than it sounds, what happened when six cities modeled telling people to stay inside, and why your breathing rate during a set of squats matters more than you would think.Second: the effective reps model. A subscriber noticed that if a set only counts when you are within five reps of failure, the triceps in a heavy bench press should not count, and if you are going to count that as a fractional set for the triceps, then a warm-up set counts for the chest. Both cannot be true. We go through the meta-regression on proximity to failure, the 67-study analysis that tested whether an indirect set should count as one, as half, or as zero, and where we actually put our sets.Join Barbell Medicine Plus today: https://barbellmedicine.supercast.com/Buy the book, Signal: https://www.barbellmedicine.com/shop/learning/signal/New Barbell Medicine Hybrid 5K and 10K Run + Lift ProgramsBarbell Medicine coaching and templates: https://www.barbellmedicine.comTimestamps1:47 The question: is there a point where the air is too bad to train?2:37 What PM2.5 actually is3:05 AQI vs micrograms, and why your phone disagrees with the paper3:50 Where the "90 minutes" number comes from4:54 Austin: what breathing this air does to your lungs9:14 1.5 million adults: does dirty air cancel the benefit of exercise?10:44 Six cities modeled staying indoors. Mortality did not improve.11:22 Lifting vs cycling: breathing rate is the whole mechanism12:33 Indoor air during a wildfire, and what filtration does not fix13:24 Is wildfire smoke worse than city pollution?14:38 What we would actually tell a patient18:35 The question: hard sets, fractional sets, and the five-rep rule19:18 Reps in reserve, hard sets, and fractional sets defined20:19 The meta-regression: no threshold, just a line21:13 Do indirect sets count as half a set?23:08 Would you rather: every set at 5 RIR, or every set to failure?25:22 Why you get worse at judging RIR the further you are from failure28:42 The numbers we use: RPE 7 to 9 for hypertrophy, 4 to 6 for strength29:20 Austin: individual variation dwarfs all of this33:28 Why nobody can measure training load in the weight roomResourcesTainio M, de Nazelle AJ, Götschi T, et al. Can air pollution negate the health benefits of cycling and walking? Prev Med. 2016;87:233-236. doi:10.1016/j.ypmed.2016.02.002. PMID 27156248Ku PW, Steptoe A, Hamer M, et al. Does ambient PM2.5 reduce the protective association of leisure-time physical activity with mortality? A systematic review, meta-analysis, and individual-level pooled analysis of cohort studies involving 1.5 million adults. BMC Med. 2025;23(1):647. doi:10.1186/s12916-025-04496-y. PMID 41310726Giallouros G, Kouis P, Papatheodorou SI, Woodcock J, Tainio M. The long-term impact of restricting cycling and walking during high air pollution days on all-cause mortality: health impact assessment study. Environ Int. 2020;140:105679. doi:10.1016/j.envint.2020.105679. PMID 32353667Sun S, Cao W, Qiu H, et al. Benefits of physical activity not affected by air pollution: a prospective cohort study. Int J Epidemiol. 2020;49(1):142-152. doi:10.1093/ije/dyz184. PMID 31504557Robles P, Araujo T, Brooks D, et al. Cardiorespiratory responses to short bouts of resistance training exercises in individuals with chronic obstructive pulmonary disease: a comparison of exercise intensities. J Cardiopulm Rehabil Prev. 2017;37(5):356-362. doi:10.1097/HCR.0000000000000282. PMID 28858033Liang Y, Sengupta D, Campmier MJ, Lunderberg DM, Apte JS, Goldstein AH. Wildfire smoke impacts on indoor air quality assessed using crowdsourced data in California. Proc Natl Acad Sci U S A. 2021;118(36):e2106478118. doi:10.1073/pnas.2106478118. PMID 34465624Aguilera R, Corringham T, Gershunov A, Benmarhnia T. Wildfire smoke impacts respiratory health more than fine particles from other sources: observational evidence from Southern California. Nat Commun. 2021;12(1):1493. doi:10.1038/s41467-021-21708-0. PMID 33674571US Environmental Protection Agency. Air Quality Index (AQI) breakpoints. Air Quality System code tables. Accessed August 10, 2026. https://aqs.epa.gov/aqsweb/documents/codetables/aqi_breakpoints.htmlRobinson ZP, Pelland JC, Remmert JF, Refalo MC, Jukic I, Steele J, et al. Exploring the dose-response relationship between estimated resistance training proximity to failure, strength gain, and muscle hypertrophy: a series of meta-regressions. Sports Med. 2024;54(9):2209-2231. doi:10.1007/s40279-024-02069-2. PMID 38970765Pelland JC, Remmert JF, Robinson ZP, Hinson SR, Zourdos MC. The resistance training dose response: meta-regressions exploring the effects of weekly volume and frequency on muscle hypertrophy and strength gains. Sports Med. 2026;56(2):481-505. doi:10.1007/s40279-025-02344-wOur Sponsors:* Check out Cometeer and use my code BBM for a great deal: https://www.cometeer.com* Check out Cometeer and use my code BBM for a great deal: https://www.cometeer.com* Check out FIGS and use my code FIGSRX for a great deal: https://wearfigs.com* Check out Factor and use my code factormeals.com/bbm50off for a great deal: https://www.factor75.com* Check out Quince and use my code BBM for a great deal: https://www.quince.comAdvertising Inquiries: https://redcircle.com/brands

Most lifters have been told they need to eat in a Calorie surplus to build muscle. That rule has always come with a list of exceptions: unless you're new, unless you're carrying extra body fat, unless you're coming back from time off. Dr. Eric Helms joins Dr. Jordan Feigenbaum to work out what the rule is actually tracking, starting from a question with a real number attached: what does a pound of muscle cost to build? And then, do you need to be in a surplus to build muscle? Timestamps:0:00 The rule, and its exceptions2:08 Where "you need a surplus" came from7:12 Heuristics versus theories11:40 Hypertrophy, maintenance, deficit and surplus defined14:58 Body fat as a savings account18:24 How fast anyone can actually build muscle23:39 What sets the ceiling: stimulus, not genetics26:37 Microgravity, astronauts, and a 20 kg barbell31:49 What constrains growth if steroids don't break the ceiling36:44 If training sets the ceiling, what does energy do38:45 What 1 kg of muscle costs to build44:05 Why 3,500 Calories doesn't tell you what to eat44:55 REDs and the dual intervention model47:51 The 2000s bulking studies51:34 Garthe 2013: elite athletes and a 500 Calorie surplus58:30 Protein: 1.6 versus 2.5 g/kg1:03:31 What starvation research shows the body protects1:10:29 Vargas-Molina: maintenance versus deficit1:19:17 What to do if you're lean1:39:34 What would prove this wrong1:57:57 Three bucketsResources:Buy the book, Signal: https://www.barbellmedicine.com/shop/learning/signal/New Barbell Medicine Hybrid 5K and 10K Run + Lift ProgramsBarbell Medicine coaching and templates: https://www.barbellmedicine.comNikolaidis MG, Paschalis V, Margaritelis NV. The energetic cost of building human skeletal muscle. bioRxiv. Preprint posted online August 17, 2026. doi:10.64898/2026.08.17.745156Rozenek R, Ward P, Long S, Garhammer J. Effects of high-calorie supplements on body composition and muscular strength following resistance training. J Sports Med Phys Fitness. 2002;42(3):340-347.Garthe I, Raastad T, Refsnes PE, Koivisto A, Sundgot-Borgen J. Effect of two different weight-loss rates on body composition and strength and power-related performance in elite athletes. Int J Sport Nutr Exerc Metab. 2011;21(2):97-104.Garthe I, Raastad T, Refsnes PE, Sundgot-Borgen J. Effect of nutritional intervention on body composition and performance in elite athletes. Eur J Sport Sci. 2013;13(3):295-303. doi:10.1080/17461391.2011.643923Helms ER, Zinn C, Rowlands DS, Brown SR. A systematic review of dietary protein during caloric restriction in resistance trained lean athletes: a case for higher intakes. Int J Sport Nutr Exerc Metab. 2014;24(2):127-138. doi:10.1123/ijsnem.2013-0054Slater GJ, Dieter BP, Marsh DJ, Helms ER, Shaw G, Iraki J. Is an energy surplus required to maximize skeletal muscle hypertrophy associated with resistance training. Front Nutr. 2019;6:131. doi:10.3389/fnut.2019.00131Murphy C, Koehler K. Energy deficiency impairs resistance training gains in lean mass but not strength: a meta-analysis and meta-regression. Scand J Med Sci Sports. 2022;32(1):125-137. doi:10.1111/sms.14075Helms ER, Spence A, Sousa C, et al. Effect of small and large energy surpluses on strength, muscle, and skinfold thickness in resistance-trained individuals: a parallel groups design. Sports Med Open. 2023;9(1):102. doi:10.1186/s40798-023-00651-yMountjoy M, Ackerman KE, Bailey DM, et al. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). Br J Sports Med. 2023;57(17):1073-1097. doi:10.1136/bjsports-2023-106994Speakman JR, Hall KD. Models of body weight and fatness regulation. Philos Trans R Soc Lond B Biol Sci. 2023;378(1888):20220231. doi:10.1098/rstb.2022.0231Vargas-Molina S, García-Palumbo A, García-Sillero M, et al. Comparison of two nutritional protocols in body re-composition of resistance-trained participants. Eur J Appl Physiol. 2026;126(7):4019-4030. doi:10.1007/s00421-026-06209-6Our Sponsors:* Check out Cometeer and use my code BBM for a great deal: https://www.cometeer.com* Check out Cometeer and use my code BBM for a great deal: https://www.cometeer.com* Check out FIGS and use my code FIGSRX for a great deal: https://wearfigs.com* Check out Factor and use my code factormeals.com/bbm50off for a great deal: https://www.factor75.com* Check out Quince and use my code BBM for a great deal: https://www.quince.comAdvertising Inquiries: https://redcircle.com/brands

Muscle is where most of the glucose goes, and muscle insulin resistance is the first thing that breaks on the road to type 2 diabetes. Both of those are true, and neither one means that building more muscle is the treatment for obesity. This episode works through what actually decides whether a tissue handles fuel well: not how much of it you have, but how fast it's moving fuel through. We go through the one-legged exercise studies, the 18,000-person analysis of what body composition actually predicts, the athlete's paradox, the energy cost of building a kilogram of muscle, the GLP-1 lean mass panic, and why sarcopenic obesity is named after the wrong organ.This is part two of a two-part series on storage capacity. Part one covered where body fat goes and what happens when the storage runs out. Timestamps0:00   The one-leg study, and the muscle-centric claim02:06   What obesity is, and the garage analogy05:06   How glucose gets into a muscle cell11:21   Insulin sensitivity improves without building muscle17:11   The best case for muscle-centric medicine21:13   What predicts falls and death: strength, not lean mass25:18   Separating muscle size from muscle function31:33   Liver fat: amount, type, and flux37:54   Should you build muscle first? The arithmetic42:37   Building muscle in a calorie deficit50:29   GLP-1s, DXA, and the lean mass panic58:23   Sarcopenic obesity, and why the name is wrong01:04:37 Why size still tells you something01:11:46 So what is obesity?Resources:Buy the book, Signal: https://www.barbellmedicine.com/shop/learning/signal/New Barbell Medicine Hybrid 5K and 10K Run + Lift ProgramsBarbell Medicine coaching and templates: https://www.barbellmedicine.com1.   Richter EA, Mikines KJ, Galbo H, Kiens B. Effect of exercise on insulin action in human skeletal muscle. J Appl Physiol (1985). 1989;66(2):876-885. doi:10.1152/jappl.1989.66.2.876. PMID: 2496078. https://doi.org/10.1152/jappl.1989.66.2.8762.   Cawthon PM, Travison TG, Manini TM, et al. Establishing the link between lean mass and grip strength cut points with mobility disability and other health outcomes. J Gerontol A Biol Sci Med Sci. 2020;75(7):1317-1323. doi:10.1093/gerona/glz081. PMID: 30869772. https://doi.org/10.1093/gerona/glz0813.   Bhasin S, Travison TG, Manini TM, et al. Sarcopenia definition: the position statements of the Sarcopenia Definition and Outcomes Consortium. J Am Geriatr Soc. 2020;68(7):1410-1418. doi:10.1111/jgs.16372. PMID: 32150289. https://doi.org/10.1111/jgs.163724.   Elgaddal N, Kramarow EA, Reuben C. Physical activity among adults aged 18 and over: United States, 2020. NCHS Data Brief No. 443. Hyattsville, MD: National Center for Health Statistics; 2022. PMID: 36043905. https://www.cdc.gov/nchs/products/databriefs/db443.htm5.   Whitfield GP, Carlson SA, Ussery EN, Fulton JE, Galuska DA, Petersen R. Trends in meeting physical activity guidelines among urban and rural dwelling adults, United States, 2008-2017. MMWR Morb Mortal Wkly Rep. 2019;68(23):513-518. doi:10.15585/mmwr.mm6823a1. PMID: 31194722. https://doi.org/10.15585/mmwr.mm6823a16.   Wang T, Wang J, Hu X, Huang XJ, Chen GX. Current understanding of glucose transporter 4 expression and functional mechanisms. World J Biol Chem. 2020;11(3):76-98. doi:10.4331/wjbc.v11.i3.76. PMID: 33274014. https://doi.org/10.4331/wjbc.v11.i3.767.   DeFronzo RA, Tripathy D. Skeletal muscle insulin resistance is the primary defect in type 2 diabetes. Diabetes Care. 2009;32(Suppl 2):S157-S163. doi:10.2337/dc09-S302. PMID: 19875544. https://doi.org/10.2337/dc09-S3028.   Richter EA, Hargreaves M. Exercise, GLUT4, and skeletal muscle glucose uptake. Physiol Rev. 2013;93(3):993-1017. doi:10.1152/physrev.00038.2012. PMID: 23899560. https://doi.org/10.1152/physrev.00038.20129.   Petersen KF, Dufour S, Savage DB, et al. The role of skeletal muscle insulin resistance in the pathogenesis of the metabolic syndrome. Proc Natl Acad Sci U S A. 2007;104(31):12587-12594. doi:10.1073/pnas.0705408104. PMID: 17640906. https://doi.org/10.1073/pnas.070540810410. Rabøl R, Petersen KF, Dufour S, Flannery C, Shulman GI. Reversal of muscle insulin resistance with exercise reduces postprandial hepatic de novo lipogenesis in insulin resistant individuals. Proc Natl Acad Sci U S A. 2011;108(33):13705-13709. doi:10.1073/pnas.1110105108. PMID: 21808028. https://doi.org/10.1073/pnas.111010510811. Perseghin G, Price TB, Petersen KF, et al. Increased glucose transport-phosphorylation and muscle glycogen synthesis after exercise training in insulin-resistant subjects. N Engl J Med. 1996;335(18):1357-1362. doi:10.1056/NEJM199610313351804. PMID: 8857019. https://doi.org/10.1056/NEJM19961031335180412. Mikines KJ, Sonne B, Farrell PA, Tronier B, Galbo H. Effect of physical exercise on sensitivity and responsiveness to insulin in humans. Am J Physiol. 1988;254(3 Pt 1):E248-E259. doi:10.1152/ajpendo.1988.254.3.E248. PMID: 3126668. https://doi.org/10.1152/ajpendo.1988.254.3.E24813. Mikines KJ, Sonne B, Tronier B, Galbo H. Effects of acute exercise and detraining on insulin action in trained men. J Appl Physiol (1985). 1989;66(2):704-711. doi:10.1152/jappl.1989.66.2.704. PMID: 2496077. https://doi.org/10.1152/jappl.1989.66.2.70414. Yu R, Duncombe SL, Nemoto Y, et al. Physical activity trajectories and mortality. Br J Sports Med. 2025;59(17):1228-1241. doi:10.1136/bjsports-2024-109122. PMID: 40639966. https://doi.org/10.1136/bjsports-2024-10912215. Saint-Maurice PF, Coughlan D, Kelly SP, et al. Association of leisure-time physical activity across the adult life course with all-cause and cause-specific mortality. JAMA Netw Open. 2019;2(3):e190355. doi:10.1001/jamanetworkopen.2019.0355. PMID: 30848809. https://doi.org/10.1001/jamanetworkopen.2019.035516. Wang Y, Luo D, Liu J, Song Y, Jiang B, Jiang H. Low skeletal muscle mass index and all-cause mortality. PLoS One. 2023;18(6):e0286745. doi:10.1371/journal.pone.0286745. PMID: 37288745. https://doi.org/10.1371/journal.pone.028674517. Umpierre D, Ribeiro PAB, Kramer CK, et al. Physical activity advice only or structured exercise training and association with HbA1c levels in type 2 diabetes. JAMA. 2011;305(17):1790-1799. doi:10.1001/jama.2011.576. PMID: 21540423. https://doi.org/10.1001/jama.2011.57618. Goodpaster BH, Carlson CL, Visser M, et al. Attenuation of skeletal muscle and strength in the elderly: the Health ABC Study. J Appl Physiol (1985). 2001;90(6):2157-2165. doi:10.1152/jappl.2001.90.6.2157. PMID: 11356778. https://doi.org/10.1152/jappl.2001.90.6.215719. Paquin J, Lagacé JC, Brochu M, Dionne IJ. Exercising for insulin sensitivity, is there a mechanistic relationship with quantitative changes in skeletal muscle mass? Front Physiol. 2021;12:656909. doi:10.3389/fphys.2021.656909. PMID: 34054574. https://doi.org/10.3389/fphys.2021.65690920. Eriksson J, Taimela S, Eriksson K, Parviainen S, Peltonen J, Kujala U. Resistance training in the treatment of non-insulin-dependent diabetes mellitus. Int J Sports Med. 1997;18(4):242-246. doi:10.1055/s-2007-972627. PMID: 9231838. https://doi.org/10.1055/s-2007-97262721. Cuff DJ, Meneilly GS, Martin A, Ignaszewski A, Tildesley HD, Frohlich JJ. Effective exercise modality to reduce insulin resistance in women with type 2 diabetes. Diabetes Care. 2003;26(11):2977-2982. doi:10.2337/diacare.26.11.2977. PMID: 14578226. https://doi.org/10.2337/diacare.26.11.297722. Bucci M, Huovinen V, Guzzardi MA, et al. Resistance training improves skeletal muscle insulin sensitivity in elderly offspring of overweight and obese mothers. Diabetologia. 2016;59(1):77-86. doi:10.1007/s00125-015-3780-8. PMID: 26486356. https://doi.org/10.1007/s00125-015-3780-823. Mavros Y, Kay S, Anderberg KA, et al. Changes in insulin resistance and HbA1c are related to exercise-mediated changes in body composition in older adults with type 2 diabetes: interim outcomes from the GREAT2DO trial. Diabetes Care. 2013;36(8):2372-2379. doi:10.2337/dc12-2196. PMID: 23474589. https://doi.org/10.2337/dc12-219624. Janssen I, Heymsfield SB, Wang ZM, Ross R. Skeletal muscle mass and distribution in 468 men and women aged 18-88 yr. J Appl Physiol (1985). 2000;89(1):81-88. doi:10.1152/jappl.2000.89.1.81. PMID: 10904038. https://doi.org/10.1152/jappl.2000.89.1.8125. Orwoll ES, Peters KE, Hellerstein M, Cummings SR, Evans WJ, Cawthon PM. The importance of muscle versus fat mass in sarcopenic obesity: a re-evaluation using D3-creatine muscle mass versus DXA lean mass measurements. J Gerontol A Biol Sci Med Sci. 2020;75(7):1362-1368. doi:10.1093/gerona/glaa064. PMID: 32232396. https://doi.org/10.1093/gerona/glaa06426. Holten MK, Zacho M, Gaster M, Juel C, Wojtaszewski JFP, Dela F. Strength training increases insulin-mediated glucose uptake, GLUT4 content, and insulin signaling in skeletal muscle in patients with type 2 diabetes. Diabetes. 2004;53(2):294-305. doi:10.2337/diabetes.53.2.294. PMID: 14747278. https://doi.org/10.2337/diabetes.53.2.29427. Manca A, Dragone D, Dvir Z, Deriu F. Cross-education of muscular strength following unilateral resistance training: a meta-analysis. Eur J Appl Physiol. 2017;117(11):2335-2354. doi:10.1007/s00421-017-3720-z. PMID: 28936703. https://doi.org/10.1007/s00421-017-3720-z28. Bilet L, Phielix E, van de Weijer T, et al. One-leg inactivity induces a reduction in mitochondrial oxidative capacity, intramyocellular lipid accumulation and reduced insulin signalling upon lipid infusion. Diabetologia. 2020;63(6):1211-1222. doi:10.1007/s00125-020-05128-1. PMID: 32185462. https://doi.org/10.1007/s00125-020-05128-129. Lee J, Kim D, Kim C. Resistance training for glycemic control, muscular strength, and lean body mass in old type 2 diabetic patients: a meta-analysis. Diabetes Ther. 2017;8(3):459-473. doi:10.1007/s13300-017-0258-3. PMID: 28382531. https://doi.org/10.1007/s13300-017-0258-330. Goodpaster BH, He J, Watkins S, Kelley DE. Skeletal muscle lipid content and insulin resistance: evidence for a paradox in endurance-trained athletes. J Clin Endocrinol Metab. 2001;86(12):5755-5761. doi:10.1210/jcem.86.12.8075. PMID: 11739435. https://doi.org/10.1210/jcem.86.12.807531. Amati F, Dubé JJ, Alvarez-Carnero E, et al. Skeletal muscle triglycerides, diacylglycerols, and ceramides in insulin resistance: another paradox in endurance-trained athletes? Diabetes. 2011;60(10):2588-2597. doi:10.2337/db10-1221. PMID: 21873552. https://doi.org/10.2337/db10-122132. Bergman BC, Perreault L, Hunerdosse DM, Koehler MC, Samek AM, Eckel RH. Increased intramuscular lipid synthesis and low saturation relate to insulin sensitivity in endurance-trained athletes. J Appl Physiol (1985). 2010;108(5):1134-1141. doi:10.1152/japplphysiol.00684.2009. PMID: 20299618. https://doi.org/10.1152/japplphysiol.00684.200933. Dubé JJ, Amati F, Stefanovic-Racic M, Toledo FGS, Sauers SE, Goodpaster BH. Exercise-induced alterations in intramyocellular lipids and insulin resistance: the athlete's paradox revisited. Am J Physiol Endocrinol Metab. 2008;294(5):E882-E888. doi:10.1152/ajpendo.00769.2007. PMID: 18319352. https://doi.org/10.1152/ajpendo.00769.200734. Dubé JJ, Amati F, Toledo FGS, et al. Effects of weight loss and exercise on insulin resistance, and intramyocellular triacylglycerol, diacylglycerol and ceramide. Diabetologia. 2011;54(5):1147-1156. doi:10.1007/s00125-011-2065-0. PMID: 21327867. https://doi.org/10.1007/s00125-011-2065-035. Ter Horst KW, Vatner DF, Zhang D, et al. Hepatic insulin resistance is not pathway selective in humans with nonalcoholic fatty liver disease. Cell Rep. 2017;19(10):1997-2004. doi:10.1016/j.celrep.2017.05.035. PMID: 28591572. PMCID: PMC5469939. https://doi.org/10.1016/j.celrep.2017.05.03536. Lyu K, Zhang Y, Zhang D, et al. A membrane-bound diacylglycerol species induces PKCepsilon-mediated hepatic insulin resistance. Cell Metab. 2020;32(4):654-664.e5. doi:10.1016/j.cmet.2020.08.001. PMID: 32882164. PMCID: PMC7544641. https://doi.org/10.1016/j.cmet.2020.08.00137. Sargeant JA, Gray LJ, Bodicoat DH, et al. The effect of exercise training on intrahepatic triglyceride and hepatic insulin sensitivity: a systematic review and meta-analysis. Obes Rev. 2018;19(10):1446-1459. doi:10.1111/obr.12719. PMID: 30092609. https://doi.org/10.1111/obr.1271938. Rinella ME, Lazarus JV, Ratziu V, et al. A multisociety Delphi consensus statement on new fatty liver disease nomenclature. Hepatology. 2023;78(6):1966-1986. doi:10.1097/HEP.0000000000000520. PMID: 37363821. https://doi.org/10.1097/HEP.000000000000052039. Stine JG, DiJoseph K, Pattison Z, et al. Exercise training is associated with treatment response in liver fat content by magnetic resonance imaging independent of clinically significant body weight loss in patients with nonalcoholic fatty liver disease: a systematic review and meta-analysis. Am J Gastroenterol. 2023;118(7):1204-1213. doi:10.14309/ajg.0000000000002098. PMID: 36705333. https://doi.org/10.14309/ajg.000000000000209840. Mucinski JM, Salvador AF, Moore MP, et al. Histological improvements following energy restriction and exercise: the role of insulin resistance in resolution of MASH. J Hepatol. 2024;81(5):781-793. doi:10.1016/j.jhep.2024.06.017. PMID: 38914313. PMCID: PMC12007730. ClinicalTrials.gov NCT03151798. https://doi.org/10.1016/j.jhep.2024.06.01741. Nikolaidis MG, Paschalis V, Margaritelis NV. The energetic cost of building human skeletal muscle. bioRxiv. Preprint posted August 20, 2026. doi:10.64898/2026.08.17.745156. Preprint, not peer reviewed. https://doi.org/10.64898/2026.08.17.74515642. Helms ER, Spence AJ, Sousa C, et al. Effect of small and large energy surpluses on strength, muscle, and skinfold thickness in resistance-trained individuals: a parallel groups design. Sports Med Open. 2023;9(1):102. doi:10.1186/s40798-023-00651-y. PMID: 37914977. https://doi.org/10.1186/s40798-023-00651-y43. Murphy C, Koehler K. Energy deficiency impairs resistance training gains in lean mass but not strength: a meta-analysis and meta-regression. Scand J Med Sci Sports. 2022;32(1):125-137. doi:10.1111/sms.14075. PMID: 34623696. https://doi.org/10.1111/sms.1407544. Elia M, Stubbs RJ, Henry CJ. Differences in fat, carbohydrate, and protein metabolism between lean and obese subjects undergoing total starvation. Obes Res. 1999;7(6):597-604. doi:10.1002/j.1550-8528.1999.tb00720.x. PMID: 10574520. https://doi.org/10.1002/j.1550-8528.1999.tb00720.x45. Colles SL, Dixon JB, Marks P, Strauss BJ, O'Brien PE. Preoperative weight loss with a very-low-energy diet: quantitation of changes in liver and abdominal fat by serial imaging. Am J Clin Nutr. 2006;84(2):304-311. doi:10.1093/ajcn/84.1.304. PMID: 16895876. https://doi.org/10.1093/ajcn/84.1.30446. Vargas-Molina S, García-Palumbo A, García-Sillero M, et al. Effects of a moderate caloric deficit on body composition in resistance-trained individuals. Eur J Appl Physiol. 2026;126(7):4019-4030. doi:10.1007/s00421-026-06209-6. PMID: 41940947. https://doi.org/10.1007/s00421-026-06209-647. Longland TM, Oikawa SY, Mitchell CJ, Devries MC, Phillips SM. Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: a randomized trial. Am J Clin Nutr. 2016;103(3):738-746. doi:10.3945/ajcn.115.119339. PMID: 26817506. https://doi.org/10.3945/ajcn.115.11933948. Wilding JPH, Batterham RL, Calanna S, et al. Once-weekly semaglutide in adults with overweight or obesity. N Engl J Med. 2021;384(11):989-1002. doi:10.1056/NEJMoa2032183. PMID: 33567185. https://doi.org/10.1056/NEJMoa203218349. Wilding JPH, Batterham RL, Davies M, et al. Impact of semaglutide on body composition in adults with overweight or obesity: exploratory analysis of the STEP 1 study. J Endocr Soc. 2021;5(Suppl 1):A16-A17. doi:10.1210/jendso/bvab048.030. https://doi.org/10.1210/jendso/bvab048.03050. Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide once weekly for the treatment of obesity. N Engl J Med. 2022;387(3):205-216. doi:10.1056/NEJMoa2206038. PMID: 35658024. https://doi.org/10.1056/NEJMoa220603851. Look M, Dunn JP, Kushner RF, et al. Body composition changes during weight reduction with tirzepatide in the SURMOUNT-1 study of adults with obesity or overweight. Diabetes Obes Metab. 2025;27(5):2720-2729. doi:10.1111/dom.16275. PMID: 39996356. https://doi.org/10.1111/dom.1627552. Wang Z, Deurenberg P, Wang W, Pietrobelli A, Baumgartner RN, Heymsfield SB. Hydration of fat-free body mass: review and critique of a classic body-composition constant. Am J Clin Nutr. 1999;69(5):833-841. doi:10.1093/ajcn/69.5.833. PMID: 10232621. https://doi.org/10.1093/ajcn/69.5.83353. Wang ZM, Pierson RN Jr, Heymsfield SB. The five-level model: a new approach to organizing body-composition research. Am J Clin Nutr. 1992;56(1):19-28. doi:10.1093/ajcn/56.1.19. PMID: 1609756. https://doi.org/10.1093/ajcn/56.1.1954. Wadden TA, Neiberg RH, Wing RR, et al. Four-year weight losses in the Look AHEAD study: factors associated with long-term success. Obesity (Silver Spring). 2011;19(10):1987-1998. doi:10.1038/oby.2011.230. PMID: 21779086. https://doi.org/10.1038/oby.2011.23055. Fildes A, Charlton J, Rudisill C, Littlejohns P, Prevost AT, Gulliford MC. Probability of an obese person attaining normal body weight: cohort study using electronic health records. Am J Public Health. 2015;105(9):e54-e59. doi:10.2105/AJPH.2015.302773. PMID: 26180980. https://doi.org/10.2105/AJPH.2015.30277356. Alissou M, Demangeat T, Folope V, et al. Effect of semaglutide on sarcopenic obesity. Diabetes Obes Metab. 2026;28(1):112-121. doi:10.1111/dom.70141. PMID: 41068996. https://doi.org/10.1111/dom.7014157. Bansal MB, Patton H, Morgan TR, Carr RM, Dranoff JA, Allen AM. Semaglutide therapy for metabolic dysfunction-associated steatohepatitis: November 2025 updates to AASLD Practice Guidance. Hepatology. 2025;83(5):1326-1340. doi:10.1097/HEP.0000000000001608. PMID: 41201884. https://doi.org/10.1097/HEP.000000000000160858. Sardeli AV, Komatsu TR, Mori MA, Gáspari AF, Chacon-Mikahil MPT. Resistance training prevents muscle loss induced by caloric restriction in obese elderly individuals: a systematic review and meta-analysis. Nutrients. 2018;10(4):423. doi:10.3390/nu10040423. PMID: 29596307. https://doi.org/10.3390/nu1004042359. Rosenberg IH. Summary comments. Am J Clin Nutr. 1989;50(5):1231-1233. doi:10.1093/ajcn/50.5.1231. Not indexed in PubMed. https://doi.org/10.1093/ajcn/50.5.123160. Rosenberg IH. Sarcopenia: origins and clinical relevance. J Nutr. 1997;127(5 Suppl):990S-991S. doi:10.1093/jn/127.5.990S. PMID: 9164280. https://doi.org/10.1093/jn/127.5.990S61. Kirk B, Cawthon PM, Arai H, et al. The conceptual definition of sarcopenia: Delphi consensus from the Global Leadership Initiative in Sarcopenia. Age Ageing. 2024;53(3):afae052. doi:10.1093/ageing/afae052. PMID: 38520141. https://doi.org/10.1093/ageing/afae05262. Goodpaster BH, Park SW, Harris TB, et al. The loss of skeletal muscle strength, mass, and quality in older adults: the Health, Aging and Body Composition Study. J Gerontol A Biol Sci Med Sci. 2006;61(10):1059-1064. doi:10.1093/gerona/61.10.1059. PMID: 17077199. https://doi.org/10.1093/gerona/61.10.105963. Pascual-Fernández J, Fernández-Montero A, Córdova-Martínez A, Pastor D, Martínez-Rodríguez A, Roche E. Sarcopenia: molecular pathways and potential targets for intervention. Int J Mol Sci. 2020;21(22):8844. doi:10.3390/ijms21228844. PMID: 33266508. https://doi.org/10.3390/ijms2122884464. Kwon YN, Yoon SS. Sarcopenia: neurological point of view. J Bone Metab. 2017;24(2):83-89. doi:10.11005/jbm.2017.24.2.83. PMID: 28642851. https://doi.org/10.11005/jbm.2017.24.2.8365. Batsis JA, Villareal DT. Sarcopenic obesity in older adults: aetiology, epidemiology and treatment strategies. Nat Rev Endocrinol. 2018;14(9):513-537. doi:10.1038/s41574-018-0062-9. PMID: 30065268. https://doi.org/10.1038/s41574-018-0062-966. Lincoff AM, Brown-Frandsen K, Colhoun HM, et al. Semaglutide and cardiovascular outcomes in obesity without diabetes. N Engl J Med. 2023;389(24):2221-2232. doi:10.1056/NEJMoa2307563. PMID: 37952131. https://doi.org/10.1056/NEJMoa230756367. Deanfield J, Lincoff AM, Kahn SE, et al. Impact of semaglutide on cardiovascular outcomes by adiposity measures in SELECT. Lancet. 2025;406(10516):2257-2268. doi:10.1016/S0140-6736(25)01375-3. PMID: 41138739. https://doi.org/10.1016/S0140-6736(25)01375-368. Perkovic V, Tuttle KR, Rossing P, et al. Effects of semaglutide on chronic kidney disease in patients with type 2 diabetes. N Engl J Med. 2024;391(2):109-121. doi:10.1056/NEJMoa2403347. PMID: 38785209. https://doi.org/10.1056/NEJMoa240334769. Obesity Medicine Association. Definition of obesity. https://obesitymedicine.org/blog/why-is-obesity-a-disease/70. Tomiyama AJ, Hunger JM, Nguyen-Cuu J, Wells C. Misclassification of cardiometabolic health when using body mass index categories in NHANES 2005-2012. Int J Obes (Lond). 2016;40(5):883-886. doi:10.1038/ijo.2016.17. PMID: 26841729. https://doi.org/10.1038/ijo.2016.17Our Sponsors:* Check out Cometeer and use my code BBM for a great deal: https://www.cometeer.com* Check out Cometeer and use my code BBM for a great deal: https://www.cometeer.com* Check out FIGS and use my code FIGSRX for a great deal: https://wearfigs.com* Check out Factor and use my code factormeals.com/bbm50off for a great deal: https://www.factor75.com* Check out Quince and use my code BBM for a great deal: https://www.quince.comAdvertising Inquiries: https://redcircle.com/brands

Most men who start testosterone never needed it, and some who genuinely do never get treated. In the final episode of the Signal series, Dr. Jordan Feigenbaum and Dr. Austin Baraki work through who actually needs testosterone replacement, who got sold it, and what the evidence says about the risks that scared the field for a decade. We cover the blinded trial where men couldn't tell real testosterone from placebo, what the heart and prostate data actually show now that we have the trials, what testosterone does to fertility, and the framework we use to decide. We also close the story of Mark, the patient whose lab result started the series.This is educational content, not medical advice. Talk to your physician about your personal situation.Here we cover the real diagnosis of testosterone deficiency, primary versus secondary low testosterone, how the system both over- and under-prescribes, the SHBG trap that makes a normal level look low, the gray-zone crossover study, what replacement should actually target, why most men quit within a year, testosterone as a male contraceptive, the TRAVERSE cardiovascular results, the saturation model and prostate safety, the blood side effect worth monitoring, and when not to start at all.Timestamps:00:00 The study almost nobody mentions 01:31 Who this episode is for 03:35 What a real testosterone diagnosis requires 07:18 Primary vs secondary low testosterone 10:12 How testosterone gets over-prescribed 11:35 The SHBG trap: when a low number misleads 18:10 Would GLP-1 plus testosterone work better? 22:19 Why genuine deficiency gets under-treated 24:15 The cardiovascular scare and where it came from 34:11 The gray-zone study, in full 41:02 What TRT should actually target, and the "900" myth 47:38 Running TRT as a trial, and why 70% quit 52:36 Testosterone as a contraceptive: the fertility cost 57:19 Does TRT cause heart problems? The TRAVERSE trial 01:01:40 Testosterone and the prostate 01:09:13 The blood side effect worth watching 01:12:02 When not to start testosterone 01:14:26 Who actually benefits from TRT 01:18:28 The Signal framework, and what happened to Mark 01:21:14 Five things to take away 01:23:33 Our conflict of interest, and the bookResources:Buy the book, Signal: https://www.barbellmedicine.com/shop/learning/signal/Part 1: Is the testosterone crisis real?Part 2: Is you testosterone actually low?Part 3: What's actually driving your testosterone down?New Barbell Medicine Hybrid 5K and 10K Run + Lift ProgramsBarbell Medicine coaching and templates: https://www.barbellmedicine.comTestosterone Action Plan: https://www.barbellmedicine.com/testosterone-action-plan/ Mulligan T, Frick MF, Zuraw QC, Stemhagen A, McWhirter C. Prevalence of hypogonadism in males aged at least 45 years: the HIM study. Int J Clin Pract. 2006;60(7):762-769. doi:10.1111/j.1742-1241.2006.00992.xBaillargeon J, Urban RJ, Ottenbacher KJ, Pierson KS, Goodwin JS. Trends in androgen prescribing in the United States, 2001-2011. JAMA Intern Med. 2013;173(15):1465-1466. doi:10.1001/jamainternmed.2013.6895Bhasin S, Brito JP, Cunningham GR, et al. Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2018;103(5):1715-1744. doi:10.1210/jc.2018-00229Mulhall JP, Trost LW, Brannigan RE, et al. Evaluation and management of testosterone deficiency: AUA guideline. J Urol. 2018;200(2):423-432. doi:10.1016/j.juro.2018.03.115Corona G, Goulis DG, Huhtaniemi I, et al. European Academy of Andrology (EAA) and European Society of Endocrinology (ESE) recommendations on the diagnosis and management of male hypogonadism. Andrology. 2020;8(5):970-987. doi:10.1111/andr.12770Morgentaler A, Zitzmann M, Traish AM, et al. Commentary: who is a candidate for testosterone therapy? A synthesis of international expert opinions. J Sex Med. 2014;11(7):1636-1645. doi:10.1111/jsm.12546Mok SF, Fennell C, Savkovic S, et al. Testosterone for androgen deficiency-like symptoms in men without pathologic hypogonadism: a randomized, placebo-controlled cross-over with masked choice extension clinical trial. J Gerontol A Biol Sci Med Sci. 2020;75(9):1723-1731. doi:10.1093/gerona/glz195Clift AK, Johnson H, Huang DR, Morgentaler A. Real-world outcomes and safety of testosterone therapy: a longitudinal, retrospective cohort study of over 9,000 men. World J Mens Health. 2026;44(2):438-450. doi:10.5534/wjmh.250245Malik RD, Wang CE, Lapin B, Lakeman JC, Helfand BT. Characteristics of men undergoing testosterone replacement therapy and adherence to follow-up recommendations in a metropolitan multicenter health care system. Urology. 2015;85(6):1382-1388. doi:10.1016/j.urology.2015.01.027Donatucci C, Cui Z, Fang Y, Muram D. Long-term treatment patterns of testosterone replacement medications. J Sex Med. 2014;11(8):2092-2099. doi:10.1111/jsm.12608Saad F, Aversa A, Isidori AM, Zafalon L, Zitzmann M, Gooren L. Onset of effects of testosterone treatment and time span until maximum effects are achieved. Eur J Endocrinol. 2011;165(5):675-685. doi:10.1530/EJE-11-0221Ly LP, Liu PY, Handelsman DJ. Rates of suppression and recovery of human sperm output in testosterone-based hormonal contraceptive regimens. Hum Reprod. 2005;20(6):1733-1740. doi:10.1093/humrep/deh834Liu PY, Swerdloff RS, Christenson PD, Handelsman DJ, Wang C; Hormonal Male Contraception Summit Group. Rate, extent, and modifiers of spermatogenic recovery after hormonal male contraception: an integrated analysis. Lancet. 2006;367(9520):1412-1420. doi:10.1016/S0140-6736(06)68614-5Ko EY, Siddiqi K, Brannigan RE, Sabanegh ES Jr. Empirical medical therapy for idiopathic male infertility: a survey of the American Urological Association. J Urol. 2012;187(3):973-978. doi:10.1016/j.juro.2011.10.137Kohn TP, Louis MR, Pickett SM, et al. Age and duration of testosterone therapy predict time to return of sperm count after human chorionic gonadotropin therapy. Fertil Steril. 2017;107(2):351-357.e1. doi:10.1016/j.fertnstert.2016.10.004Wenker EP, Dupree JM, Langille GM, et al. The use of HCG-based combination therapy for recovery of spermatogenesis after testosterone use. J Sex Med. 2015;12(6):1334-1337. doi:10.1111/jsm.12890Basaria S, Coviello AD, Travison TG, et al. Adverse events associated with testosterone administration. N Engl J Med. 2010;363(2):109-122. doi:10.1056/NEJMoa1000485Vigen R, O’Donnell CI, Barón AE, et al. Association of testosterone therapy with mortality, myocardial infarction, and stroke in men with low testosterone levels. JAMA. 2013;310(17):1829-1836. doi:10.1001/jama.2013.280386Basaria S, Harman SM, Travison TG, et al. Effects of testosterone administration for 3 years on subclinical atherosclerosis progression in older men with low or low-normal testosterone levels: a randomized clinical trial. JAMA. 2015;314(6):570-581. doi:10.1001/jama.2015.8881Budoff MJ, Ellenberg SS, Lewis CE, et al. Testosterone treatment and coronary artery plaque volume in older men with low testosterone. JAMA. 2017;317(7):708-716. doi:10.1001/jama.2016.21043Lincoff AM, Bhasin S, Flevaris P, et al. Cardiovascular safety of testosterone-replacement therapy. N Engl J Med. 2023;389(2):107-117. doi:10.1056/NEJMoa2215025Huggins C, Hodges CV. Studies on prostatic cancer. I. The effect of castration, of estrogen and of androgen injection on serum phosphatases in metastatic carcinoma of the prostate. Cancer Res. 1941;1(4):293-297.Morgentaler A, Traish AM. Shifting the paradigm of testosterone and prostate cancer: the saturation model and the limits of androgen-dependent growth. Eur Urol. 2009;55(2):310-320. doi:10.1016/j.eururo.2008.09.024Khera M, Crawford D, Morales A, Salonia A, Morgentaler A. A new era of testosterone and prostate cancer: from physiology to clinical implications. Eur Urol. 2014;65(1):115-123. doi:10.1016/j.eururo.2013.08.015Bhasin S, Lincoff AM, Nissen SE, et al. Prostate safety events during testosterone replacement therapy in men with hypogonadism: a randomized clinical trial. JAMA Netw Open. 2023;6(12):e2348692. doi:10.1001/jamanetworkopen.2023.48692Snyder PJ, Bhasin S, Cunningham GR, et al. Effects of testosterone treatment in older men. N Engl J Med. 2016;374(7):611-624. doi:10.1056/NEJMoa1506119Our Sponsors:* Check out Cometeer and use my code BBM for a great deal: https://www.cometeer.com* Check out Cometeer and use my code BBM for a great deal: https://www.cometeer.com* Check out FIGS and use my code FIGSRX for a great deal: https://wearfigs.com* Check out Factor and use my code factormeals.com/bbm50off for a great deal: https://www.factor75.com* Check out Quince and use my code BBM for a great deal: https://www.quince.comAdvertising Inquiries: https://redcircle.com/brands