How GLP-1s Affect Muscle Mass

Semaglutide, sold as Ozempic and Wegovy, and tirzepatide, sold as Zepbound and Mounjaro, are new weight loss drugs that actually work, helping millions around the world to feel better and become healthier. But some people are fearful of side effects, such as loss of muscle mass. Are their fears warranted? To find out, Marty and Stu talk to the two University of Kansas weight loss scientists, Renee Rogers and ACSM president-elect John Jakicic, who are leading a clinical trial investigating the way aerobic and resistance training can affect the muscle mass of people who are on GLP-1s, or the other new weight loss drugs. In this episode we discuss: —the latest findings on how GLP-1s affect muscle mass —the difference between lean mass and muscle mass —the research that Jakicic and Rogers are doing into GLP-1s, weight loss and muscle mass —we provide guidance on whether people should be concerned about GLP-1s and muscle mass —we also provide pointers on how to minimize muscle loss while on GLP-1s Plus, Renee and John answer a listener question about whether the new weight loss drugs affect men and women differently. Have a listener question or an idea for a future episode? Email us at [realexercisescience@gmail.com](mailto:realexercisescience@gmail.com) Exercise Science is powered by EverMe, the longevity intelligence app. Exercise Science listeners get a free two-month trial to EverMe at this link. You can also download EverMe for free at your favourite app store. **LINKS** Follow or subscribe at your favourite platform @realexercisescience: Substack. YouTube. TikTok. Instagram. Apple Podcasts. Spotify. On X you can find us @realexscience. Stu is everywhere, too, but mostly on Instagram and X. Follow him on TikTok too! Marty just started his own Instagram. Give him a follow! He’s also on X!Exercise Science is produced by Ghost Bureau, the Toronto content agency. **EPISODE LINKS** New York Times: They Hated Exercise. Weight Loss Drugs Changed Everything. Renee Rogers and John Jakicic’s clinical trial: Muscle and Movement With Anti-Obesity Medications (M3) A paper by John Jakicic and Renee Rogers advocating for a prescription of exercise along with obesity medication in obesity treatment: The Role of Exercise in the Contemporary Era of Obesity Management Medications - ACSM-CSMR Jakicic led, and Rogers coauthored, the largest targeted NIH investment of funds into the mechanisms of how physical activity improves health and prevents disease. Study website. Article from the Journal of Applied Physiology: Molecular Transducers of Physical Activity Consortium (MoTrPAC): human studies design and protocol Analysis: Preserving muscle mass on GLP-1 weight loss drugs: Big Deal or Nothing to Worry About? By Stuart Phillips **DISCUSSION POINTS** 00:00 Cold open 01:29 Muscle mass and GLP-1s 04:19 Introducing Renee and John 06:19 GLP-1 context 07:50 How GLP-1s work 10:50 More than GLP-1s 12:44 Body composition & weight loss 15:00 Lean tissue is not muscle 16:50 Overblown fears 18:55 Muscle moment 20:39 R01 study described 23:15 Early results 26:04 Behavioural influences 28:45 Rediscovering exercise 31:09 Comprehensive care 33:00 Renting weight loss 36:55 Obesity drivers 37:47 Older adults 40:39 Wraparound care 41:30 Muscle health context 43:12 Function measures matter 44:44 Lean v. muscle 46:15 Unloading the body 47:40 GLP-1 sex differences 49:44 How to minimize muscle loss on GLP-1s 53:33 Wrap up **DISCLAIMER** The Exercise Science podcast is for educational and entertainment purposes only and is not a substitute for professional medical advice. Strength training and fitness carry inherent risks. Always consult with a physician or qualified healthcare provider before starting any new exercise program or making changes to your diet. The hosts, producers, sponsors and guests of this podcast disclaim any liability for any injuries or losses connected with the information discussed in this show. The science of strength and fitness is continually evolving. While we strive to provide accurate, evidence-based information, we make no representations or warranties regarding the completeness, accuracy, or timeliness of the information discussed. Martin Gibala is an advisor to and holds equity in Longevity League Ltd., a US-based company whose services in part relate to exercise. This is a public episode. If you would like to discuss this with other subscribers or get access to bonus episodes, visit www.realexercisescience.com