Show Notes
A methods-focused episode about how muscle and body-composition measurements can mislead you when reading the research. The main event is a new Balshaw and colleagues paper concluding that ultrasound muscle thickness is a poor index of MRI-measured muscle growth. Trexler and Helms argue this shouldn't be read as "throw out all ultrasound research" — the real culprit is that muscle thickness is a crude one-dimensional snapshot with measurement error large enough to swamp the small changes seen in typical short studies, whereas MRI captures growth in more dimensions with better fidelity. They walk through why comparing across different dimensions and different devices matters, what researchers can do about it (bigger doses, larger samples, multiple measurements), and use the famous "sleep restriction kills your gains by 60%" study as an example of over-reading a tiny difference in ten people. The second half turns to DEXA. Prompted by someone confused that DEXA fat mass didn't line up with the 3,500-calorie rule, they explain DEXA's three-compartment model, why it measures fat mass rather than adipose tissue, and why lean soft tissue readings are so sensitive to hydration. The practical upshot: don't build your worldview on a kilogram of day-to-day DEXA noise, be cautious using DEXA to estimate energy status, and understand that flattening a three-dimensional body into a two-dimensional scan introduces real limits. They close with an extended, tongue-in-cheek bit about trademarking "muscle journey" dimensions. Iron Culture is proudly presented by the MASS Research Review. Mostly because Helms and Trex are co-owners. massresearchreview.com If you're in the market for some new (ultra-high-quality) gym gear or apparel, be sure to use code "MRR10" for a 10% discount over at elitefts.com If you'd like to submit a question for a future episode, head over to: massresearchreview.com/ironculture Chapters 0:00 Intro 5:57 The paper: is ultrasound a poor muscle-growth measure? 18:04 What muscle thickness actually captures 25:38 Measurement error vs. a tiny signal 31:16 Different dimensions, different devices 37:52 What researchers should do about it 39:26 Case study: does sleep loss "kill gains"? 47:28 On to DEXA: where this started 53:26 How DEXA works & why fat mass ≠ adipose tissue 1:02:15 Why methods don't always agree 1:11:06 Water weight & the whooshing scale 1:16:43 Estimating energy status from DEXA 1:19:36 Wrap-up
More from Iron Culture presented by MASS
Trexler and Helms step back from training specifics to talk about how science gets interpreted, communicated, and applied. Trexler opens with two anecdotes that exposed a blind spot in his own communication — a one-minute clip of a talk on the Minnesota starvation experiment that drew online backlash, and a classroom tangent on macaque calorie-restriction research that a colleague worried could nudge students toward disordered eating — both cases where true, interesting science left too much room for misapplied conclusions. That leads into the academic-versus-applied distinction (when an idea is "ready for showtime"), what Trexler has absorbed from science communicators and evolutionary-biology seminars outside fitness, the case for structuring science as story, leading with a question rather than an attack on social media, and modeling intellectual humility. The back half covers how to tell when information isn't "ready for prime time," a worked example from a Mass article on weight-variability research, and the shared pull — across researchers, communicators, and audiences alike — to carry findings past what the evidence supports.
Trexler and Helms dig into training frequency and hypertrophy, prompted by a wave of recent discussion and two new papers: a new original study comparing three weekly sessions of three sets against one session of nine, and a new preprint from an independent research team utilizing the openly available data from Pelland's previously published meta-regression. They trace the long history of the frequency debate (including Helms's own shifting position), review where the science had settled, and put the current online discourse and the reanalysis under the microscope. The back half turns practical: a state-of-the-science recap, higher frequency as a tool for distributing volume and managing fatigue, and "zigging where the data zags," with a personal example of practical application. Join us for new episodes of Iron Culture, Tuesdays at 5:30 pm eastern time! Be sure to use code "MRR10" for 10% off your order at elitefts.com Iron Culture is proudly presented by the MASS Research Review massresearchreview.com Chapters 0:00 Intro & business 5:30 Tonight's topic: frequency & hypertrophy 8:54 A history of the frequency debate 21:19 Where the science had settled 29:33 The new claim & study under the microscope 42:39 The state of the science 56:24 Distributing volume & managing fatigue 1:04:52 Zigging where the data zags (a practical application) 1:18:32 Wrap-up
In this episode, Eric Helms and Steve Hall explore the nature of aging, the importance of self-awareness, and practical insights into nutrition and training for bodybuilders. They share personal stories, scientific perspectives, and coaching tips to help listeners optimize their health and performance. Catch new Iron Culture episodes every Tuesday at 5:30 pm eastern time! Be sure to use code "MRR10" for 10% off your order at elitefts.com Iron Culture is proudly presented by the MASS Research Review massresearchreview.com
This episode looks at bodybuilding before steroids became widespread, arguing that the era is far more useful (and more complicated) than the usual "pure, simple, natty golden age" story. Drs Eric Helms and Conor Heffernan break down how strength sport, judging standards, gym access, and culture shaped physiques from the 1940s through the 1950s. The big takeaway is that early bodybuilding was not a direct comparison to modern natural bodybuilding. The sport was tied to Olympic weightlifting, evaluated with very different criteria, and influenced by training tools and social norms that changed the entire game. Catch new Iron Culture episodes every Tuesday at 5:30 pm eastern time! Be sure to use code "MRR10" for 10% off your order at elitefts.com Iron Culture is proudly presented by the MASS Research Review massresearchreview.com Chapters 0:00 Intro 5:20 The "pre-steroid era" myth 13:48 Using history to break the rules 15:22 When did steroids actually arrive? 29:13 Were the silver-era physiques natural? 32:11 What the average lifter really looked like 39:33 Why old physiques look so different 43:02 Photography before Photoshop 51:37 Inside the Mr. America contest 1:05:27 Training shifts & the Weider–Hoffman rivalry 1:09:21 Equipment & accessibility 1:21:24 Why training volume was limited 1:22:41 The machine age changes everything 1:31:43 How your entry point shapes you 1:37:05 Lessons from the pre-steroid era 1:42:36 The "banned" lifts that were once normal 1:44:50 Wrap-up
Bodybuilders are laser-focused on retaining as much muscle as possible while dieting, and for very good reason. In that context, the smallest details matter. But what about everybody else? This episode explores a hot take on weight loss, lean mass loss, and why the usual fear of losing muscle may be overstated in the context of successful long-term weight loss. Drs Eric Helms and Eric Trexler break down what lean mass loss actually represents, how body composition changes in obesity differ from bodybuilding or weight cycling, and why the health benefits of sustained fat loss substantially outweigh moderate losses in fat-free mass. Catch new Iron Culture episodes every Tuesday at 5:30 pm eastern time! Be sure to use code "MRR10" for 10% off your order at elitefts.com Iron Culture is proudly presented by the MASS Research Review massresearchreview.com Chapters 00:00 Introduction 15:16 Helms' hot take on losing lean mass 19:02 Defining lean mass loss 23:28 Why obesity increases fat-free mass 30:14 Temporary versus lasting muscle loss 35:05 DEXA versus MRI measurements 42:12 Prioritizing function and quality of life 47:29 Obesity, stigma, and public health 73:35 Weighing health benefits against muscle loss