Barbell Medicine Podcast

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 Intro
2:33 2,500 years of people picking up heavy things
7:24 George Windship and the Health Lift
10:56 Blaikie's truck horse and the muscle-bound myth
14:59 Bernarr Macfadden
19:39 Charles Atlas and Dynamic Tension
27:01 Carl Klein, a homemade device, and the parallel squat
30:57 Thomas Delorme and three sets of ten
35:20 Kids, growth plates, and where the stunting idea came from
41:43 Women, "you'll get bulky," and Dudley Sargent in 1912
50:05 Pregnancy, from 1949 to a 2025 barbell study
53:40 The pattern, and the curve on next week's graph

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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 Programs
Barbell Medicine coaching and templates: https://www.barbellmedicine.com

Timestamps
1:47 The question: is there a point where the air is too bad to train?
2:37 What PM2.5 actually is
3:05 AQI vs micrograms, and why your phone disagrees with the paper
3:50 Where the "90 minutes" number comes from
4:54 Austin: what breathing this air does to your lungs
9:14 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 mechanism
12:33 Indoor air during a wildfire, and what filtration does not fix
13:24 Is wildfire smoke worse than city pollution?
14:38 What we would actually tell a patient
18:35 The question: hard sets, fractional sets, and the five-rep rule
19:18 Reps in reserve, hard sets, and fractional sets defined
20:19 The meta-regression: no threshold, just a line
21:13 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 failure
28:42 The numbers we use: RPE 7 to 9 for hypertrophy, 4 to 6 for strength
29:20 Austin: individual variation dwarfs all of this
33:28 Why nobody can measure training load in the weight room

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US 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.html
Robinson 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 38970765
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

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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 exceptions
2:08 Where "you need a surplus" came from
7:12 Heuristics versus theories
11:40 Hypertrophy, maintenance, deficit and surplus defined
14:58 Body fat as a savings account
18:24 How fast anyone can actually build muscle
23:39 What sets the ceiling: stimulus, not genetics
26:37 Microgravity, astronauts, and a 20 kg barbell
31:49 What constrains growth if steroids don't break the ceiling
36:44 If training sets the ceiling, what does energy do
38:45 What 1 kg of muscle costs to build
44:05 Why 3,500 Calories doesn't tell you what to eat
44:55 REDs and the dual intervention model
47:51 The 2000s bulking studies
51:34 Garthe 2013: elite athletes and a 500 Calorie surplus
58:30 Protein: 1.6 versus 2.5 g/kg
1:03:31 What starvation research shows the body protects
1:10:29 Vargas-Molina: maintenance versus deficit
1:19:17 What to do if you're lean
1:39:34 What would prove this wrong
1:57:57 Three buckets

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Nikolaidis MG, Paschalis V, Margaritelis NV. The energetic cost of building human skeletal muscle. bioRxiv. Preprint posted online August 17, 2026. doi:10.64898/2026.08.17.745156
Rozenek 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:10.1080/17461391.2011.643923
Helms 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.2013-0054
Slater 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.2019.00131
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
Helms 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-y
Mountjoy 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-2023-106994
Speakman 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.2022.0231
Vargas-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/s00421-026-06209-6

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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. 
Timestamps
0:00   The one-leg study, and the muscle-centric claim
02:06   What obesity is, and the garage analogy
05:06   How glucose gets into a muscle cell
11:21   Insulin sensitivity improves without building muscle
17:11   The best case for muscle-centric medicine
21:13   What predicts falls and death: strength, not lean mass
25:18   Separating muscle size from muscle function
31:33   Liver fat: amount, type, and flux
37:54   Should you build muscle first? The arithmetic
42:37   Building muscle in a calorie deficit
50:29   GLP-1s, DXA, and the lean mass panic
58:23   Sarcopenic obesity, and why the name is wrong
01:04:37 Why size still tells you something
01:11:46 So what is obesity?

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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 book

Resources:
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 Programs
Barbell Medicine coaching and templates: https://www.barbellmedicine.com
Testosterone Action Plan: https://www.barbellmedicine.com/testosterone-action-plan/ 

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