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.

Timestamps

• 00:00 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 instead

Resources:

• 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.com
• Nicotine 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 Plan
• New Barbell Medicine Hybrid 5K and 10K Run + Lift Programs

1. Baz-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-2022-0017
2. Pedersen 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.12055
3. Currier 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.0000000000003897
4. 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
5. Refalo 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-y
6. Robinson 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/s40279-024-02069-2
7. Isenmann 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-y
8. Šrámek 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/s004210050065
9. Buijze 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.0161749
10. Søberg 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.2021.100408
11. Cain 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.0317615
12. Muzik 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.112.111336
13. Shattock 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.2012.229864
14. Grgic 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:10.1080/17461391.2022.2033851
15. Leproult 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.86.1.7102
16. Epstein 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-47-2-397
17. Kageyama 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.0.1350147
18. Methlie 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-11-0518
19. Sigurjónsdóttir 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.1001215
20. Lilja 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.x
21. Chida 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.2008.10.004
22. Vastbinder 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.
23. Johnston JG, Pollock DM. Circadian regulation of renal function. Free Radic Biol Med. 2018;119:93-107. doi:10.1016/j.freeradbiomed.2018.01.018
24. Jordan 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.101.5.504
25. Killer 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.0084154
26. Hakam 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.2024.47621
27. Altieri 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/s40618-025-02673-7
28. Zick 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:10.1186/1472-6882-11-78
29. Howatson 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/s00394-011-0263-7
30. Pase 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.0000000000004373
31. Qaseem 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/M15-2175
32. Trauer 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/M14-2841
33. Ferracioli-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.0063773
34. Burgess 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.2009-2590
35. Erland 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.6462
36. McCurry 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.2016.1795
37. The 2022 hormone therapy position statement of The North American Menopause Society. Menopause. 2022;29(7):767-794. doi:10.1097/GME.0000000000002028
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39. Griesar WS, Zajdel DP, Oken BS. Nicotine effects on alertness and spatial attention in non-smokers. Nicotine Tob Res. 2002;4(2):185-194. doi:10.1080/14622200210123617
40. Heishman 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/s00213-010-1848-1
41. DiFranza 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.11.3.228
42. Travis 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/ntag203
43. Antonio 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:10.1186/1550-2783-11-19
44. Delimaris I. Adverse effects associated with protein intake above the recommended dietary allowance for adults. ISRN Nutr. 2013;2013:126929. doi:10.5402/2013/126929
45. Matta 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.2019.20747
46. Ding 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)00164-1
47. Engeroff 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/s40279-022-01808-7
48. Gulati 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.110.93924

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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.

Timestamps

• 00:00 A 22-year-old needs a form signed
• 02:16 The history and exam
• 05:49 Reading his EKG 
• 13:13 The echo and the MRI
• 18:26 The rest of the workup, and Austin commits to a diagnosis
• 24:02 Patient course
• 27:54 What his care team decided
• 29:45 How much the heart changes with training
• 36:45 A second case that went differently
• 41:52 Should a finding like this end a career
• 45:47 Should an EKG be mandatory for amateur athletes
• 55:59 What would actually move the needle

Resources

Buy the book, Signal: https://www.barbellmedicine.com/shop/learning/signal/

Free Vital 5 Action Plan

New Barbell Medicine Hybrid 5K and 10K Run + Lift Programs

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

Get 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:
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* 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.com


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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 plunges
• 19:44 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 4
• 1:56 Mouth tape, Zone 2, and saunas 
• 47:44 What actually works

Resources

• Buy the book, Signal: https://www.barbellmedicine.com/shop/learning/signal/
• Free Vital 5 Action Plan
• New Barbell Medicine Hybrid 5K and 10K Run + Lift Programs
• Barbell Medicine coaching and templates: https://www.barbellmedicine.com
• Get 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/

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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.

Timestamps

• 00:00 The jogging J-curve and the headlines
• 02:42 The Danish study, its confidence interval, and what a MET measures
• 08:02 Better measurement: 15 check-ins and fitness on a treadmill
• 12:51 Atrial fibrillation: the dose, the mechanism, and stroke risk
• 22:06 Coronary calcium and heart scarring in masters athletes
• 25:58 The marathon death story and cardiac arrest rates
• 29:08 How much training it takes to keep getting fitter
• 34:12 Does cardio interfere with your lifting gains
• 39:52 Flux, the athlete's paradox, and liver fat
• 44:12 Cardio, weight loss, and metabolic compensation
• 51:13 Bone density in cyclists and energy availability
• 57:51 Writing the cardio guidelines

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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.2026.01.025

33. 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.0b013e3181c6a116

35. 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:10.1186/1741-7015-10-168

36. 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.2016.02.013

37. 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-2018-000424

38. 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-2019-000523

39. 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-2024-108121

40. Kim JH, Malhotra R, Chiampas G, et al. Cardiac arrest during long-distance running races. N Engl J Med. 2012. doi:10.1056/NEJMoa1106468

41. 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.2023-0275

42. 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.

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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 them
• 
  

Resources

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New Barbell Medicine Hybrid 5K and 10K Run + Lift Programs

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Get early access, ad-free listening, and exclusive content here: https://barbellmedicine.supercast.com/

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28. 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.
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30. 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.
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33. 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.
34. 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.
35. 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.
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38. 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.
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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

Resources:

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

1. 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.

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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.

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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.

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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.

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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.

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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.

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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.

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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

Resources

Tainio 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 27156248

Ku 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 41310726

Giallouros 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 32353667

Sun 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 31504557

Robles 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 28858033

Liang 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 34465624

Aguilera 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 33674571

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

Resources:

Buy the book, Signal: https://www.barbellmedicine.com/shop/learning/signal/

New Barbell Medicine Hybrid 5K and 10K Run + Lift Programs

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1. 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
2. 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.
3. 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.
4. 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
5. 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
6. 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
7. 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
8. 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
9. 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
10. 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
11. 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?

Resources:

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

1.   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.1989.66.2.876

2.   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/glz081

3.   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.16372

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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?

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2. Baillargeon 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.2013.6895
3. Bhasin 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.2018-00229
4. Mulhall 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.2018.03.115
5. Corona 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.12770
6. Morgentaler 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.12546
7. Mok 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/glz195
8. Clift 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.250245
9. Malik 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.2015.01.027
10. Donatucci 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.12608
11. Saad 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-11-0221
12. Ly 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/deh834
13. Liu 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)68614-5
14. Ko 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.2011.10.137
15. Kohn 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.2016.10.004
16. Wenker 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.12890
17. Basaria 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/NEJMoa1000485
18. Vigen 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.2013.280386
19. Basaria 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.2015.8881
20. Budoff 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.2016.21043
21. Lincoff 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/NEJMoa2215025
22. Huggins 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.
23. 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.2008.09.024
24. Khera 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.2013.08.015
25. Bhasin 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.2023.48692
26. Snyder 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/NEJMoa1506119

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In 2004 a surgeon removed about ten kilograms of fat from fifteen women and measured everything that mattered. Nothing improved. Four years later, it still hadn't.

That result should have ended an argument about body fat. Instead the argument got more specific, and the version you've heard most recently is that visceral fat, the fat around your organs, is the dangerous kind. I've said a version of that myself on this show, and in this episode I expand upon it.

This one starts from the beginning: what your fat is actually for, what insulin is, and what insulin resistance means, in plain terms and assuming nothing. Then four experiments that all point the same direction. Fat removed surgically, and the disease doesn't follow. People born with no fat tissue at all, who get the entire disease anyway. A hormone that reversed a 48% fatty liver without adding a gram of fat. And a diabetes drug that made people heavier and healthier at the same time.

The second half is practical. What a fatty liver actually does over twenty years, what BMI can and can't do, why the Lancet Commission changed the definition of obesity in 2025, and the exact order of tests I'd use, including the TyG index, FIB-4, and where each one stops working.

Part one of two. Next episode is about muscle.

Timestamps:

00:00 The Liposuction Experiment

02:06 The Visceral Fat Correction

05:47 What Fat Is For

08:14 The Carb Insulin Model

10:51 Filling The Garage

14:35 Taking The Fat Out

17:57 Born Without Fat Tissue

22:52 Heavier And Healthier

25:05 Neptune And Vulcan

29:57 The Patient Nobody Checked

33:59 What Every Ruler Missed

36:00 What To Actually Order

40:29 What Obesity Actually Is

Resources:

Vital 5 (TyG , waist to height, etc. discussion):

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8. Al Yaarubi S, Alsagheir A, Al Shidhani A, et al. Analysis of disease characteristics of a large patient cohort with congenital generalized lipodystrophy from the Middle East and North Africa. Orphanet J Rare Dis. 2024;19(1):118. doi:10.1186/s13023-024-03084-2
9. Petersen KF, Oral EA, Dufour S, et al. Leptin reverses insulin resistance and hepatic steatosis in patients with severe lipodystrophy. J Clin Invest. 2002;109(10):1345-1350. doi:10.1172/JCI200215001
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12. Taylor R, Barnes AC, Hollingsworth KG, et al. Aetiology of type 2 diabetes in people with a 'normal' body mass index: testing the personal fat threshold hypothesis. Clin Sci (Lond). 2023;137(16):1333-1346. doi:10.1042/CS20230586
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14. Martin S, Sorokin EP, Thomas EL, et al. Estimating the effect of liver and pancreas volume and fat content on risk of diabetes: a Mendelian randomization study. Diabetes Care. 2022;45(2):460-468. doi:10.2337/dc21-1262
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16. Portillo-Sanchez P, Bril F, Maximos M, et al. High prevalence of nonalcoholic fatty liver disease in patients with type 2 diabetes mellitus and normal plasma aminotransferase levels. J Clin Endocrinol Metab. 2015;100(6):2231-2238. doi:10.1210/jc.2015-1966
17. Hagström H, Nasr P, Ekstedt M, et al. Fibrosis stage but not NASH predicts mortality and time to development of severe liver disease in biopsy-proven NAFLD. J Hepatol. 2017;67(6):1265-1273. doi:10.1016/j.jhep.2017.07.027
18. Rubino F, Cummings DE, Eckel RH, et al. Definition and diagnostic criteria of clinical obesity. Lancet Diabetes Endocrinol. 2025;13(3):221-262. doi:10.1016/S2213-8587(24)00316-4
19. Guerrero-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.2010-0288
20. Sánchez-García A, Rodríguez-Gutiérrez R, Mancillas-Adame L, et al. Diagnostic accuracy of the triglyceride and glucose index for insulin resistance: a systematic review. Int J Endocrinol. 2020;2020:4678526. doi:10.1155/2020/4678526
21. McLaughlin T, Abbasi F, Cheal K, Chu J, Lamendola C, Reaven G. Use of metabolic markers to identify overweight individuals who are insulin resistant. Ann Intern Med. 2003;139(10):802-809. doi:10.7326/0003-4819-139-10-200311180-00007
22. McPherson S, Hardy T, Dufour JF, et al. Age as a confounding factor for the accurate non-invasive diagnosis of advanced NAFLD fibrosis. Am J Gastroenterol. 2017;112(5):740-751. doi:10.1038/ajg.2016.453
23. Mózes FE, Lee JA, Selvaraj EA, et al. Diagnostic accuracy of non-invasive tests for advanced fibrosis in patients with NAFLD: an individual patient data meta-analysis. Gut. 2022;71(5):1006-1019. doi:10.1136/gutjnl-2021-324243
24. 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
25. 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
26. Wildman RP, Muntner P, Reynolds K, et al. The obese without cardiometabolic risk factor clustering and the normal weight with cardiometabolic risk factor clustering: prevalence and correlates of 2 phenotypes among the US population (NHANES 1999-2004). Arch Intern Med. 2008;168(15):1617-1624. doi:10.1001/archinte.168.15.1617
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35. Hinnouho GM, Czernichow S, Dugravot A, Batty GD, Kivimaki M, Singh-Manoux A. Metabolically healthy obesity and risk of mortality: does the definition of metabolic health matter? Diabetes Care. 2013;36(8):2294-2300. doi:10.2337/dc12-1654
36. Herman WH, Ye W, Griffin SJ, et al. Early detection and treatment of type 2 diabetes reduce cardiovascular morbidity and mortality: a simulation of the results of the Anglo-Danish-Dutch study of intensive treatment in people with screen-detected diabetes in primary care (ADDITION-Europe). Diabetes Care. 2015;38(8):1449-1455. doi:10.2337/dc14-2459
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* Check out Factor and use my code factormeals.com/bbm50off for a great deal: https://www.factor75.com
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