Muscle Mass & Weight Loss Drugs: Overblown Fears or Justified Concerns?

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:

—how GLP-1s affect muscle mass

—the difference between lean and muscle mass

—the research that Jakicic and Rogers are doing into GLP-1s

—guidance on whether people should be concerned about GLP-1s and muscle mass

—how to minimize muscle loss while on GLP-1s 

Plus, whether the new weight loss drugs affect men and women differently. 

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Exercise Science sponsor Precision Nutrition is the #1 most recommended nutrition certification program in the world. And now it specializes in GLP-1 coaching. For a free assessment to learn your GLP-1 type, visit GLPCoaching.com. 

LINKS

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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: The Role of Exercise in the Contemporary Era of Obesity Management Medications

Jakicic led, and Rogers coauthored, the largest NIH investment into how physical activity improves health and prevents disease. Study website. Journal article: 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.

Martin Gibala is an advisor to and holds equity in Longevity League Ltd., a US-based company whose services in part relate to exercise.