Uploaded June 2026 | Updated September 2026, 2 weeks ago
If GLP-1 medications cause the muscle loss everyone worries about, the cleanest way to settle it would be a trial with strength as the primary endpoint: drug versus placebo, training versus no training. So where are those trials? Jordan and Dr. Austin Baraki walk through what the published evidence actually shows and what is still coming.
We cover the Copenhagen trial published in the New England Journal of Medicine in 2021, where the drug-alone group lost more weight without a meaningful decline in knee-extensor strength, plus the 2024 follow-up on bone density. We get into the semaglutide data on grip strength and intramuscular fat, the BELIEVE trial pairing a myostatin-pathway antibody with semaglutide, the enobosarm work, and the trials still in progress (T-REX, a lean-mass prep study, and Regeneron’s myostatin-inhibitor programs). Most of these use grip strength or stair-climb power rather than a one-rep max, which is part of the problem.
The throughline is measurement. Much of the muscle-loss panic is an artifact of DEXA reading “lean mass” as if it were contractile muscle, when force production depends on training and neural coordination the drug does not provide. Austin closes with how he frames the strength conversation with patients starting a GLP-1: keep training, use the muscle you have, and adjust if early signs say otherwise. For infotainment purposes only; we are not your doctors. Full AMA episode and reference list linked below.
Resources:
Subscribe to BBM Plus for the full unabridged Direct Line: barbellmedicine.supercast.com
Barbell Medicine coaching and templates: barbellmedicine.com
Signal book pre-order: barbellmedicine.com/shop/learning/signal
Lundgren J.R. et al. 2021 (S-LiTE trial). Healthy weight loss maintenance with exercise, liraglutide, or both combined. N Engl J Med 384(18):1719-1730.
pubmed.ncbi.nlm.nih.gov/33951361
Jensen S.B.K. et al. 2024. Bone health after exercise alone, GLP-1 receptor agonist, or combination: follow-up of the S-LiTE trial. JAMA Netw Open 7(6):e2416775. pubmed.ncbi.nlm.nih.gov/38869898
Heymsfield S.B. et al. 2024 (BELIEVE trial). Bimagrumab and semaglutide for treatment of obesity. NEJM Evid
Pratley R.E. et al. 2024 (T-REX preliminary data).
If GLP-1 medications cause the muscle loss everyone worries about, the cleanest way to settle it would be a trial with strength as the primary endpoint: drug versus placebo, training versus no training. So where are those trials? Jordan and Dr. Austin Baraki walk through what the published evidence actually shows and what is still coming.
We cover the Copenhagen trial published in the New England Journal of Medicine in 2021, where the drug-alone group lost more weight without a meaningful decline in knee-extensor strength, plus the 2024 follow-up on bone density. We get into the semaglutide data on grip strength and intramuscular fat, the BELIEVE trial pairing a myostatin-pathway antibody with semaglutide, the enobosarm work, and the trials still in progress (T-REX, a lean-mass prep study, and Regeneron’s myostatin-inhibitor programs). Most of these use grip strength or stair-climb power rather than a one-rep max, which is part of the problem.
The throughline is measurement. Much of the muscle-loss panic is an artifact of DEXA reading “lean mass” as if it were contractile muscle, when force production depends on training and neural coordination the drug does not provide. Austin closes with how he frames the strength conversation with patients starting a GLP-1: keep training, use the muscle you have, and adjust if early signs say otherwise. For infotainment purposes only; we are not your doctors. Full AMA episode and reference list linked below.
Resources:
Subscribe to BBM Plus for the full unabridged Direct Line: barbellmedicine.supercast.com
Barbell Medicine coaching and templates: barbellmedicine.com
Signal book pre-order: barbellmedicine.com/shop/learning/signal
Lundgren J.R. et al. 2021 (S-LiTE trial). Healthy weight loss maintenance with exercise, liraglutide, or both combined. N Engl J Med 384(18):1719-1730.
pubmed.ncbi.nlm.nih.gov/33951361
Jensen S.B.K. et al. 2024. Bone health after exercise alone, GLP-1 receptor agonist, or combination: follow-up of the S-LiTE trial. JAMA Netw Open 7(6):e2416775. pubmed.ncbi.nlm.nih.gov/38869898
Heymsfield S.B. et al. 2024 (BELIEVE trial). Bimagrumab and semaglutide for treatment of obesity. NEJM Evid
Pratley R.E. et al. 2024 (T-REX preliminary data).
