Why Muscle Size Doesn’t Fully Explain Strength, with Professor Paul Comfort

How many sets does a muscle need to grow, and how much does each extra set add?In this episode of Stronger With Time, I speak with Dr Jake Remmert about volume, frequency and effort, and what the research means for how you program for muscle growth.Jake is an exercise physiology professor at Illinois State University and a strength and physique coach. He did his PhD in Dr Mike Zourdos's Muscle Physiology Laboratory at Florida Atlantic University, is one of the primary authors of the recent meta regression on per session training volume, and co-authored the dose response analysis on weekly volume, frequency and proximity to failure with Josh Pelland and Zac Robinson.Throughout, Jake makes the case that the big rocks (effort, recoverable volume and consistency over time) matter more than the fine details.Modern Hypertrophy, my four-week live course on programming for muscle growth, starts 9 November: https://go.tonyboutagy.com/modern-hypertrophy-courseIn this episode:The eras of hypertrophy thinking, and why the language has moved from certainty to nuancePer session volume, and the diminishing returns of each extra setWhy doubling your sets doesn't double your muscle growthHow many sets per session are productive for most people, and the minimum effective doseExercise variety and regional growthWhat short, controlled studies can and cannot tell usWhether training a muscle more often builds more muscle once weekly volume is matchedThe point of undetectable outcome superiority, and the millimetre differences behind the debatesHow close to failure you need to train, and whether that changes between heavy compound sets and isolation workOverload techniques such as drop sets and supersets, and what they do and do not addPeriodisation for hypertrophy, and training for the area under the curveTimestamps: 00:00 The eras of hypertrophy thinking04:23 Per session volume, and why Jake looked at it06:34 The diminishing returns of each set10:47 Finding the productive range12:17 How many sets to double your first set15:19 Regional growth and exercise variety17:47 What a ten-week study can and cannot tell you25:06 Re-analysing the open data with Mark McKean29:05 The minimum effective dose31:25 The point of undetectable outcome superiority37:26 The frequency debate47:30 Proximity to failure52:33 Overload techniques58:05 Periodisation for hypertrophy1:01:50 Rapid fire: overrated or underrated1:04:25 Where to find Jake's workDr Jake Remmert:Instagram: https://www.instagram.com/jake.remmert.phd/Website: https://jakeremmert.com/Dr Tony Boutagy / Stronger With TimeModern Hypertrophy (starts 9 November): https://go.tonyboutagy.com/modern-hypertrophy-courseWebsite: https://tonyboutagy.com/Instagram: https://www.instagram.com/tonyboutagy/This episode is for general educational purposes only and is not intended as individualised exercise advice.

Professor Roger Enoka is one of the world’s leading authorities on the neuromuscular system and has spent more than four decades studying how the nervous system produces movement, strength and fatigue. He is the author of Neuromechanics of Human Movement, now in its sixth edition.In this episode of Stronger With Time, we discuss why Type II muscle fibres are not simply high-threshold motor units, why light and heavy loads taken to failure can produce similar muscle growth despite differences in motor unit activity, and what can limit your ability to continue a set as you approach failure.In this episode, we discuss:What a motor unit is, and why muscle fibre type and recruitment threshold are not the same thingHow motor unit recruitment and rate coding change as force demands increaseLight versus heavy loads to failure, and the relationship between motor unit activity and muscle growthFatigue, fatigability and why the distinction matters when we talk about training to failureHow mechanical tension is generated and what we can measure in human muscleFree weights versus machines, and how balance and stability change the demands on the nervous systemLengthening contractions and the neural demands of controlling a loadNeuromechanical matching and regional hypertrophyMotor neuron loss, rate coding and the role of resistance training as we ageSex differences in fatigability and what they may mean for exercise prescriptionResistance training, balance and the role of impact exercise as we ageTimestamps00:00 Introduction00:52 What is a motor unit?03:20 Recruitment thresholds and the size principle04:11 Muscle fibre type versus motor unit type05:50 Fatigue, fatigability and failure14:13 Light versus heavy loads and muscle growth17:55 Mechanical tension and what we can measure in humans25:40 What happens from brain to muscle across a set29:01 Free weights versus machines30:58 Lengthening contractions34:34 Neuromechanical matching and regional growth38:15 Ageing and the nervous system42:19 Sex differences46:52 Resistance training, balance and impact exercise49:00 Where to find Roger’s workResourcesProfessor Roger EnokaUniversity of Colorado Boulder: https://www.colorado.edu/iphy/people/faculty/roger-m-enokaNeuromechanics of Human Movement, 6th Edition: https://us.humankinetics.com/products/neuromechanics-of-human-movement-6th-editionThe Science of Movement on Coursera: https://www.coursera.org/specializations/science-of-movementDr Tony Boutagy / Stronger With TimeWebsite: https://tonyboutagy.com/Explore Tony’s courses: https://tonyboutagy.com/explore-the-courses-pageInstagram: https://www.instagram.com/tonyboutagy/This episode is for general educational purposes only and is not intended as individualised exercise advice.

How much of what we do in the gym today is genuinely new, and how much has been around for decades?In this episode of Stronger With Time, I speak with Dr Conor Heffernan about where many of the training ideas we now take for granted came from, how they changed over time, and what their history can teach us about how we train today.Conor is a historian and sociologist of sport at Ulster University whose work focuses on the history of strength training and physical culture. He is the author of The History of Physical Culture and When Fitness Went Global, and writes at Physical Culture Study.In this episode:How physical culture evolved into modern bodybuilding and gym cultureEugen Sandow, the first modern physique star, and why he sold light dumbbells while training heavy himselfWhere the squat, three sets of ten and body-part splits came fromWhat lifters already understood about progressive overload by the 1930sThe steroid era, and what changed in training once anabolic steroids arrivedWhere single-set and high-intensity training came fromThe history of women in strength, from calisthenics and “toning” to progressive strength trainingWhat Conor takes from more than a century of strength-training history into how he thinks about training todayTimestamps00:00 Introduction00:57 Physical culture and the origins of modern gym culture06:28 Where three sets of ten and body-part splits came from13:08 What lifters already knew by the 1930s16:50 Eugen Sandow and early fitness marketing21:39 What a 1930s lifter would recognise today31:33 Silver Era training and the pre-steroid physique39:18 When anabolic steroids entered strength sports43:01 How steroids changed training49:18 Single-set and high-intensity training52:49 The history of women in strength59:53 Where “toning” and light weights for women came from01:06:15 What Conor takes from strength-training history01:11:23 Where to learn moreDr Conor Heffernan Ulster University: https://www.ulster.ac.uk/staff/c-heffernanPhysical Culture Study: https://physicalculturestudy.com/Physical Culture Study Substack: https://physicalculture.substack.com/BooksThe History of Physical Culture: https://cgscholar.com/publishers/books/the-history-of-physical-cultureWhen Fitness Went Global: https://www.bloomsbury.com/us/when-fitness-went-global-9781350500785/Dr Tony Boutagy / Stronger With TimeWebsite: https://tonyboutagy.com/Explore Tony’s courses: https://tonyboutagy.com/explore-the-courses-pageInstagram: https://www.instagram.com/tonyboutagy/This episode is for general educational purposes only and is not intended as individualised exercise advice.

VO2 max matters, but what else determines endurance, and how should you train for it?In this episode of Stronger With Time, I sit down with Professor Andy Jones to explore where zone two and intervals fit, what elite endurance athletes can teach us, and what this means for training, performance and healthy ageing.Andy is Professor of Applied Physiology at the University of Exeter and one of the world's leading endurance physiologists. He served as a scientific editor on Nike's Breaking2 project, worked with marathon world-record holder Paula Radcliffe for more than a decade, and has helped shape research on critical power, dietary nitrate and physiological resilience.In this episode:What VO2 max can and cannot tell you about enduranceWhere zone two fits within aerobic trainingWhether you should avoid the middle ground between easy work and hard intervalsHow Andy approaches intervals for improving VO2 maxHow to combine aerobic training with three weekly strength sessionsWhether men and women need different endurance trainingWhat Breaking2 and Paula Radcliffe reveal about endurance beyond VO2 maxWhat Andy's research shows about nitrate, beetroot and carbohydrate fuellingResources:Professor Andy JonesUniversity of Exeter academic profile: https://experts.exeter.ac.uk/1327-andy-jonesUniversity of Exeter Sports Physiology & Exercise Testing: https://sites.exeter.ac.uk/spet/meet-the-team/Dr Tony Boutagy / Stronger With TimeWebsite: https://tonyboutagy.com/Explore Tony's courses: https://tonyboutagy.com/explore-the-courses-pageInstagram: https://www.instagram.com/tonyboutagy/Follow Stronger With Time for more evidence-informed conversations on training, health and performance.This episode is for general educational purposes only and is not a training prescription or medical advice.

Two people can have similar muscle mass and very different levels of strength. What accounts for the difference?In this episode of Stronger With Time, Tony speaks with Professor Paul Comfort, one of the world’s leading strength and conditioning researchers, about what influences strength beyond muscle size, and what that means for training.Paul is Professor of Strength and Conditioning at the University of Salford in the UK, where he leads the Master of Strength and Conditioning program. He also holds an adjunct professorship at Edith Cowan University in Western Australia. His research focuses on strength training, force production and the assessment of physical performance.In this episode, they discuss:How strength is assessed, and whether a true one-repetition maximum is as fatiguing as people thinkWhether bar speed matters as much as intentWhen slow, controlled reps help, and when they may notHow psychology and neural inhibition can affect strength expressionWhat stability and unilateral work can reveal about a weak linkWhy lowering a weight is different from lifting itWhat happens when training frequency changes but weekly volume stays the same, and whether microdosing worksWhether strength, hypertrophy and power should be trained together or emphasised at different timesHow strength training priorities change with ageProfessor Paul ComfortUniversity of Salford https://www.salford.ac.uk/our-staff/paul-comfortResearchGate https://www.researchgate.net/profile/Paul-ComfortGoogle Scholar https://scholar.google.com/citations?user=xukgqDQAAAAJ&hl=enORCID https://orcid.org/0000-0002-1131-8626Instagram https://www.instagram.com/paulcomfort1975/X https://x.com/PaulComfort1975Books Advanced Strength and Conditioning https://www.routledge.com/Advanced-Strength-and-Conditioning-An-Evidence-based-Approach/Turner-Comfort/p/book/9780367491352Performance Assessment in Strength and Conditioning https://www.routledge.com/Performance-Assessment-in-Strength-and-Conditioning/Comfort-Jones/p/book/9781032831497Laboratory Manual for Strength and Conditioning https://www.routledge.com/Laboratory-Manual-for-Strength-and-Conditioning/Miller-Comfort-McMahon/p/book/9781032033259NSCA Developing Power https://us.humankinetics.com/products/developing-power-2nd-editionDr Tony Boutagy / Stronger With TimeWebsite https://tonyboutagy.com/Courses https://tonyboutagy.com/explore-the-courses-pageWeak Links in Movement https://tonyboutagy.com/weak-links-movement-full-courseInstagram https://www.instagram.com/tonyboutagy/Follow Stronger With Time for more evidence-informed conversations on training, health and performance.This episode is for general educational purposes only and is not intended as individualised exercise advice.

Most of the attention in training goes to the workout itself. But what happens after the workout that determines the result you get from it?In this episode of Stronger With Time, Tony speaks with Professor John Hawley, one of the most influential figures in exercise metabolism, about what four decades of research can teach us about how we train, fuel and recover.John is a Distinguished Professor at Australian Catholic University in Melbourne, where he directs the Centre for Human Metabolism and Performance. His research spans how exercise and diet regulate fat and carbohydrate metabolism in skeletal muscle, the molecular basis of training adaptation, circadian biology and nutrient timing, and how exercise improves insulin action.John helped run some of the pioneering interval-training studies in Cape Town in the 1990s and has spent the decades since studying the mechanisms behind how training works.In this episode:What happens inside the muscle after the workout endsHow short, hard intervals compare with longer intervals for improving VO₂max and performanceWhat high-intensity training does differently from steady-state exerciseHow often to go hard, and where lower-intensity training fitsWhy carbohydrate availability matters when the work gets hardWhen training with low carbohydrate availability may have a placeWhat the carbohydrate mouth rinse reveals about the brain’s role in performanceConcurrent training, the interference effect and when it mattersHow exercise changes insulin sensitivity and glucose disposalWhat John’s research on time-restricted eating is findingWhether sex meaningfully changes the metabolic response to exerciseWhere the search for an exercise mimetic standsHow John thinks about consistency, recovery and making exercise a priorityThis conversation is for anyone who wants to train with more intent and understand what is driving the results.ResourcesProfessor John HawleyACU profile: https://www.acu.edu.au/research-and-enterprise/our-research-institutes/mary-mackillop-institute-for-health-research/our-people/professor-john-hawleyResearch and publications: https://scholar.google.com/scholar?q=%22John+Hawley%22+exercise+metabolismOn PubMed: https://pubmed.ncbi.nlm.nih.gov/?term=Hawley+JA+exercise+metabolismBook: Peak Performance: Training and Nutritional Strategies for Sport, by John Hawley and Louise Burke https://books.google.com/books/about/Peak_Performance.html?id=3P5qQgAACAAJDr Tony Boutagy / Stronger With TimeWebsite: https://tonyboutagy.com/Explore Tony’s courses: https://tonyboutagy.com/explore-the-courses-pageInstagram: https://www.instagram.com/tonyboutagy/Subscribe to Stronger With Time for more evidence-informed conversations on training, health and performance.This episode is for general educational purposes only and is not intended as individualised exercise or nutrition advice.

How many sets should you do? How often should you train a muscle? How close to failure should you go?Before answering any of those questions, I want to know what the program is trying to achieve and what the person can recover from.In this episode of Stronger With Time, I'm resharing a conversation I had with Ariel and Matt from Raise the Bar about the way I think about exercise programming after more than 30 years of coaching and studying exercise science.We start with how I moved from endurance sport into strength and conditioning, why I have remained a student of the field, and what decades of coaching have taught me about translating research into practice.From there, we get into the programming questions that matter in the gym, including several areas where I have changed my mind.We discuss:Why the goal and the person’s ability to recover come before sets and repsWhy the first sets of an exercise appear to give the most benefit, what my new meta-analysis changed about how quickly returns diminish, and what that means for how much you doWhy strength and hypertrophy are related, but not the same adaptationWhy mechanical tension is central to muscle growthWhat soreness, muscle damage and metabolic stress do, and do not, tell us about hypertrophyRep ranges, proximity to failure and muscle fibre recruitmentExercise selection and why some muscles benefit from biomechanically different movementsTraining frequency versus doing more volume in one sessionWhy I often favour total-body training two or three times per weekHow I approach strength training for women who want to get stronger without maximising muscle sizeHow long to keep a program and why changing exercises too quickly can matterProgressive overload, periodisation and where the evidence is still developingWhere research can guide programming and where coaching judgement still mattersWhy I'd question any program that needs a deload, and what a drop in performance is actually telling youThis conversation is for coaches, trainers and serious lifters who want to make better programming decisions without reducing exercise science to a set of universal rules.I am building a short course on the science of hypertrophy: I'm building a short course on the science of hypertrophy. Over the past year I've reviewed the hypertrophy research in full and spoken with many of the researchers behind it on this podcast, and that work has changed a few things about how I program for muscle. The short course covers exactly those changes. Join the interest list to be the first to hear when it opens:https://go.tonyboutagy.com/register-you-interest-pageIf you want the complete foundation on program design, that is Advanced Program Mastery. After all of this work, very little in it has needed to change:https://tonyboutagy.com/advanced-program-mastery-course-page

When you raise your arm, which muscles produce the movement, and which keep the shoulder stable enough for it to happen?In this episode of Stronger With Time, I speak with Professor Donald Neumann, PT, PhD, FAPTA, about how muscles produce, control and stabilise movement as part of a coordinated system, using the shoulder as the primary example.Don is Professor Emeritus of Physical Therapy at Marquette University and the author of Neumann’s Kinesiology of the Musculoskeletal System.We discuss:What it means for a muscle to be functioning wellWhy few muscles perform a meaningful action independentlyHow muscular force couples produce and control movementWhy the shoulder’s mobility places greater demands on muscular controlHow the deltoid and rotator cuff share the work of raising the armHow the serratus anterior and trapezius contribute to scapular movementWhat the commonly cited two-to-one scapulohumeral rhythm describesWhen scapular dyskinesis may warrant closer attentionWhy external-rotation strength depends partly on the muscles anchoring the scapulaWhether the lower trapezius and serratus anterior should be trained separately or within larger movementsHow anatomical variation influences the way we assess the shoulder and hipWhat Don’s current research may reveal about the actions of individual scapular musclesThis conversation is for coaches, trainers, physiotherapists and serious lifters who want a clearer understanding of what produces, controls and stabilises shoulder movement, and what this means for assessment and training.See how these principles apply to movement assessment and program design in Weak Links & Movement:https://tonyboutagy.com/weak-links-movement-full-courseProfessor Donald NeumannMarquette University profile:https://www.marquette.edu/physical-therapy/directory/donald-neumann.phpNeumann’s Kinesiology of the Musculoskeletal System, Fourth Edition:https://shop.elsevier.com/books/neumann-s-kinesiology-of-the-musculoskeletal-system/neumann/978-0-323-71859-2Review of the serratus anterior:https://pubmed.ncbi.nlm.nih.gov/30737019/Review of the trapezius:https://pubmed.ncbi.nlm.nih.gov/30797676/Professor Neumann’s publications on PubMed:https://pubmed.ncbi.nlm.nih.gov/?term=Neumann+DA%5BAuthor%5DTony Boutagy / Stronger With TimeWebsite:https://tonyboutagy.com/Explore the courses:https://tonyboutagy.com/explore-the-courses-pageInstagram:https://www.instagram.com/tonyboutagy/Apple Podcasts:https://podcasts.apple.com/us/podcast/stronger-with-time/id1815428150Spotify:https://open.spotify.com/show/5Yydg6y3dA8OiA8hyHcJON

How close to failure do you need to train to build muscle?And how accurately can you judge how many repetitions you still have in reserve?In this episode of Stronger With Time, I speak with Dr Martin Refalo about how accurately lifters can judge repetitions in reserve, how close to failure a set needs to be, and when training to failure may be useful.Martin is Co-Owner and Education Manager at JPS Health & Fitness. He holds a PhD in Exercise Science, has authored multiple peer-reviewed publications and has more than a decade of practical coaching experience. Proximity to failure and its relationship with hypertrophy, fatigue and discomfort have been central areas of his research.We discuss:Why lifters can misjudge how close they are to failureHow to develop a more accurate sense of repetitions in reserveHow close to failure Martin generally recommends trainingWhen recording a set may help calibrate effortHow fatigue across a session can affect performanceWhen training to failure may be more appropriate in lower-volume programmesWhether load and repetition range affect muscle growthWhy higher-repetition sets can be more difficult to judgeWhat the evidence suggests about sex differences in fatigue, recovery and hypertrophyWhether women require fundamentally different resistance-training programmesHow Martin designs studies around practical training questionsThis conversation is for coaches and serious lifters who want to prescribe effort with greater accuracy and understand how proximity-to-failure research applies in the gym.Timestamps:00:05 Introduction to Dr. Martin Rafalo and His Expertise01:03 Exploring Resistance Training and Training to Failure01:31 Practical Applications of Exercise Science01:56 Introduction and guest introduction02:30 Why study training to failure? The research focus05:10 Context-dependent nature of training intensity08:39 The strike zone: 2 reps shy of failure09:45 Is it worth pushing to true failure? Practical tips12:02 Perception of effort and actual proximity to failure13:46 Muscle tension, fatigue, and hypertrophy mechanisms18:04 Monitoring progress and fatigue through performance20:40 Fatigue impact across sessions and exercises25:17 Research findings on proximity to failure and growth27:31 Programming considerations: volume, load, and recovery30:54 Training to failure in beginners vs. advanced33:42 Sex differences in fatigue and recovery36:25 Applying science to coaching practice47:04 Designing research studies in exercise science51:05 Within-subject vs. group studies on failure54:08 Gender responses to resistance training58:22 Hormonal influences and muscle growth in females01:01:27 Bridging science and coaching practice01:05:10 Program design for different athlete goals01:08:10 Program duration and auto-regulation01:10:26 Where to find more about Martin RefaloDr Martin RefaloInstagram: https://www.instagram.com/mrfitness__/JPS profile: https://www.jpshealthandfitness.com.au/team/martin-refalo/JPS Education: https://www.instagram.com/jps_education/JPS Health & Fitness: https://www.jpshealthandfitness.com.au/JPS YouTube: https://www.youtube.com/channel/UCi6aTw95QXJHjv8ucdxnL7QTony Boutagy / Stronger With TimeWebsite: https://tonyboutagy.com/Explore Tony’s courses: https://tonyboutagy.com/explore-the-courses-pageInstagram: https://www.instagram.com/tonyboutagy/Subscribe to Stronger With Time for more evidence-informed conversations on training, health and performance.This episode is for general educational purposes only and is not a substitute for individualised training advice.

There is a lot of conflicting advice about how women should train and fuel through midlife.Should they prioritise high-intensity work over Zone 2? Train around the menstrual cycle? Cut back on carbohydrates?In this episode of Stronger With Time, I speak with Rachel Neylan, Olympic cyclist, world championship silver medallist, physiotherapist and high-performance coaching psychologist.We discuss under-fuelling and carbohydrate fear, bone health after years of cycling, and whether Zone 2 is really overrated for women. Rachel explains why the aerobic base that supported her professional career also helped her absorb harder training and recover from it.We also talk about training around the menstrual cycle without rigid rules, rebuilding after serious injury, the difference between motivation and identity, and creating systems around training, nutrition, sleep, recovery and community.This conversation is for women who want to stay strong, fit and capable through midlife, and for the coaches and health professionals who work with them.Timestamps00:00 Introduction01:40 Rapid-fire cycling questions06:30 Leaving physiotherapy for professional cycling09:45 Matching your physiology to the right sport14:15 Why children need variety before specialisation17:00 Movement variety for healthy ageing19:25 What endurance sport teaches you about doing hard things21:40 Motivation versus identity24:35 Training after retiring from professional sport26:15 Bone density and the hidden cost of cycling29:25 Recovering from a major crash33:15 Resilience and training around injury37:30 Under-fuelling and fear of carbohydrate42:45 Fuelling around a one-hour training session44:55 Why every workout should not be hard47:15 Is Zone 2 overrated for women?52:00 Why an aerobic base supports high-intensity training55:05 Female physiology and training differences57:50 Menstrual-cycle tracking without rigid rules01:01:25 Building a personal performance ecosystem01:04:00 Rachel’s current work in performance coaching01:06:20 Closing thoughtsResourcesRachel Neylan’s websitehttps://www.rachelneylan.com/Rachel Neylan’s Australian Olympic profilehttps://www.olympics.com.au/olympians/rachel-neylan/Tony’s websitehttps://tonyboutagy.com/Explore Tony’s courseshttps://tonyboutagy.com/explore-the-courses-pageFollow Tony on Instagramhttps://www.instagram.com/tonyboutagy/Subscribe to Stronger With Time for more evidence-informed conversations on training, health and performance.This episode is for general educational purposes only and does not constitute medical advice.