Watts Doc #54: Glycogen's Effects On AMPK

We take a deep look at ten commonly used ways to test or estimate FTP, and dissect how and why each method does (or is supposed to) work, how often we might expect accurate result and who it'd be accurate for, and the Empirical Cycling standards for test accuracy. We also dig into some data on ramp test accuracy and bias, plus how anaerobic capacity, RPE, and daily fluctuations in performance can play a role in test results. Plus time in zone, %FTP, normalized power, lactate tests, the "Kolie Moore" test, and your listener questions on DFA-alpha1, eFTP, and more.

Our coaches sit down to discuss the downsides of using FTP as an anchor for many types of intervals, how your individual physiology can make those targets suboptimal for the best stimulus, and the many alternative approaches that we use instead. We dig into VO2max, anaerobic and sprint efforts, plus first threshold and endurance riding. Then we answer your questions on minimum effective dose, breaking out of a rut, assessing realistic targets, and more.

Dr. Eric Trexler joins the podcast for a nuanced discussion on energy expenditure and endurance sports. He explains measurement methods, the constrained energy expenditure model and its interpretations, the difficulty of calculating your total energy expenditure and needs and practical solutions, some curious results from papers on energy expenditure in cycling grand tours, and much more.

Our coaches answer your questions on identifying limiters, how to take a rest week on a low volume plan, resuming training after a break, training for fitness vs racing, total time in zone vs structured intervals, the things that cyclists under-optimize, making the most of unusually large training weeks, the benefits of ice cream, and much more.

This is a critical look at our previous podcast episodes on VO2max training, and with hindsight provide new and additional context on those training recommendations, plus other effective ways to do VO2max training, with their coaching and contextual aspects. We investigate some instances of "VO2max blocks" in the scientific literature, reexamine the 30/15s paper, and discuss additional factors that confound the interpretation of those and other published results before considering how we can use that information to our advantage when training.

This is a practical guide to FTP training, through three lenses: where you are in your season, where you are in your training journey, and opportunity cost. In each instance we think about reasonable expectations for improvement, if you should add more power or interval time, when to switch to VO2max training, periodization strategies, and how to prioritize your training. We also answer listener questions on over unders, progressing longer or shorter intervals, block training, in-season maintenance, and more.

This is a dive into research showing increased AMPK activation with low glycogen stores. We break down a paper discerning how AMPK does this, subsequent changes to AMPK's activity levels, and then come to some logical training conclusions. Along the way are some takeaways on interpreting and applying mechanistic research.

Our coaches Will and Giancarlo join the podcast to talk through their experience with cramps, and what's been done to attenuate them. We briefly discuss predictors of exercise associated muscle cramps as well as current theories about why they do occur, while most of the episode is spent on practical considerations, and the long list of potential solutions.

Taking enough rest can be intimidating if it's unfamiliar territory. Our resident philosophers of rest Rory and Maeghan join to take a deep dive into the most common reasons we see people being scared of sufficient recovery. We include plenty of practical takeaways for what to expect when resting, how much is too much, building new habits, knowing when you can get back into training, what not to do, and more.

Six of our Empirical Cycling coaches put their heads together to answer your questions on whether mid season breaks will set your fitness back to the dark ages, managing burnout and disappointment, if younger athletes can still overtrain, balancing intensity and volume, work and family stress, being a "good student" as a coached athlete, training habits, and things cyclists put an emphasis on that they shouldn't.