The landscape of medications to treat obesity has rapidly changed since 2023 when we authored A Perspective on Anti-Obesity Medications. Semaglutide had captured public attention, tirzepatide was approaching approval for obesity, and dozens of new therapies were moving through development. The focus of our original perspective was: What does this mean for exercise professionals?
Today, the question is: Is the exercise profession evolving in this rapidly changing landscape?
These therapies are now referred to as obesity management medications (OMMs). This reflects recognition of obesity as a chronic disease requiring long-term management rather than a short-term pursuit of weight loss.
The landscape is quickly evolving, with multiple highly effective injectable and oral OMM options, and more advancing through research and development pipelines. Importantly, the focus is shifting from weight loss to broader health benefits related to type 2 diabetes, cardiovascular disease, chronic kidney disease, obstructive sleep apnea, and metabolic dysfunction-associated steatohepatitis.
These are not “weight-loss drugs.” They are medications being used to treat the complex chronic disease of obesity and its health complications.
The Opportunity for Exercise Has Not Changed
We positioned the emergence of effective OMMs as an enhanced opportunity for exercise. We emphasized focusing on how exercise could improve health and support quality of life, rather than on energy expenditure and weight loss, within the context of comprehensive obesity care. This should continue to be the focus.
However, exercise, particularly resistance training, is increasingly being promoted as the solution to “protect,” “preserve,” or even “build” muscle during obesity treatment. While the concern about muscle loss is reasonable, claims about fully preserving muscle and lean tissue with exercise during substantial weight loss exceed the available evidence.
Lean Mass Is Not Muscle Mass
Lean mass is not synonymous with muscle mass, and common measures of body composition do not directly measure muscle. Lean mass includes water, organs, connective tissues, other non-adipose components, in addition to muscle. During substantial weight reduction, changes in some of these compartments may be expected and, in some cases, reflect health improvements.
We also do not yet adequately understand what proportion of lean soft-tissue loss during contemporary obesity pharmacotherapy represents actual muscle tissue. This is why our group and others are actively investigating these questions.
Exercise Does Not Make Underlying Biology Disappear
Historically, lean tissue is not completely preserved during substantial weight loss, even when exercise is included. Thus, claims stating that exercise will “prevent muscle loss” with GLP-1–based therapies may not be accurate.
There are good physiological reasons to be cautious. Accreting skeletal muscle is challenging in a hypocaloric state. We cannot assume that what we know about resistance training and hypertrophy under other physiological conditions will result in a similar response with substantial weight reduction that is assisted with an OMM.
Emerging data of exercise combined with contemporary OMMs are reinforcing the need to separate changes in body composition from other important adaptations to exercise. These data demonstrate that a patient can lose some lean tissue and simultaneously become stronger, fitter, more physically capable, and experience better quality of life with exercise.
From One Metric Obsession to Another
For decades, the emphasis with exercise was on weight change, while downplaying the other health benefits of exercise within obesity treatment. With a shift from weight to body composition, we need to be careful not to overemphasize body composition metrics. Body composition is an important clinical signal, but similar to weight, it doesn’t fully represent health gains. Thus, overemphasizing a number on a body-composition report, is not person-centered care.
Instead, we should also be asking, can this person:
- Climb stairs more easily?
- Get off the floor? Play with their children or grandchildren?
- Maintain independence? Become stronger?
- Feel less fatigued? Improve cardiorespiratory fitness?
- Develop a relationship with movement that can be sustained?
And perhaps most importantly: How do they feel and function every day?
Weight Loss Is Not the End of Obesity Care
Obesity treatment does not end when weight loss levels off.
Obesity is a chronic, relapsing disease, and long-term disease management remains necessary. Exercise may play an important role in that long-term relationship, but enthusiasm for exercise should not run ahead of evidence.
We currently do not have evidence that exercise, or building muscle, allows patients to “off-ramp” OMMs. OMMs are intended for chronic management, and reducing or discontinuing treatment can allow the biological drivers of obesity to re-emerge. Exercise has profound independent health benefits, and this should be the emphasis of exercise rather than focusing on off-ramping the OMM.
The Next Opportunity: A Better-Trained Exercise Profession
We previously emphasized that effective exercise counseling in this new era would require appropriately trained exercise professionals prepared to work alongside clinicians treating obesity. Today, that call is even more urgent with a need for contemporary obesity-specific education within the exercise profession. Exercise and sports medicine professionals need education in the biology and heterogeneity of obesity; weight bias and stigma; contemporary treatment approaches; body composition and its limitations; behavioral and environmental barriers to movement; and the role of exercise within multidisciplinary, long-term obesity management.
To meet this educational need, ACSM’s Obesity Care Exercise Specialist Certificate course was developed. It’s intentionally not focused only on “GLP-1.” Rather, it is built around a larger premise: if exercise professionals are to participate meaningfully in the care of people living with obesity, they first need to understand the disease they are helping to manage.
As obesity therapies become more effective and comprehensive care continues to evolve, the opportunities for exercise professionals are enhanced. However, this requires higher qualification standards to participate in obesity care.
It’s time to move beyond teaching exercise professionals simply how to help someone lose weight, or preserve muscle, and instead prepare them to participate in person-centered obesity care. The future will be defined by how well we use science and not our professional bias to support the individual living with the disease of obesity to feel, function, and live better each day.
Renee J. Rogers, PhD, FACSM, is an expert in developing bio-behavioral healthy lifestyle interventions for obesity treatment with special focus on physical activity and relevant strategies to promote long-term success. She has worked in obesity and physical activity research and programming for 20+ years playing many professional roles that include working as an instructor, practitioner, program director, researcher, designer, and consultant and strategist to large corporations. She blends her background in production with her formal academic training in exercise physiology, body composition and quality, bio-behavior interaction, and comprehensive care to develop and implement innovative initiatives that encourage well-being, healthy lifestyle engagement, and person-centered approaches. Her current work is focused on body composition, tissue quality and function, and comprehensive lifestyle factors related to contemporary obesity treatments and pharmacotherapy. Dr. Rogers also serves in leadership and committee roles for the American College of Sports Medicine and The Obesity Society, and has recently created ACSM’s Obesity Care Exercise Specialist Certificate to educate exercise professionals on understanding obesity as a disease, engagement on comprehensive care teams, and implementing person-centered exercise and obesity programming.
John M. Jakicic, PhD, FACSM, ACSM-CEP, is a professor at the University of Kansas Medical Center in the Department of Internal Medicine and the Division of Physical Activity and Weight Management. Central to his interdisciplinary research program is a focus on the prevention and treatment of obesity as a chronic disease that includes lifestyle, pharmacotherapy, and metabolic and bariatric surgery. He also has expertise in body composition methodology applied to research and clinical settings. He served on national committees focused on obesity, physical activity, and other chronic health conditions, which included his appointment by the US Department of Health and Human Services to the 2018 Physical Activity Guidelines Scientific Advisory Committee. He authored the 2024 American College of Sport Medicine’s Consensus paper focused on obesity and excess adiposity, and he is currently the President-Elect of the American College of Sports Medicine.
Sara J. Kovacs, PhD, FACSM, is an associate professor of instruction and Undergraduate Program Director in the Department of Health and Rehabilitation Sciences at Temple University. She has extensive training in physical activity, weight management, and obesity care, with research focused on improving participation and long-term engagement in physical activity among individuals living with obesity or undergoing metabolic bariatric surgery. As an educator, Dr. Kovacs prepares current and future exercise professionals to promote physical activity in inclusive, sustainable, and evidence-based ways. She has expertise in active learning and learner-centered teaching strategies that enhance student engagement and support meaningful learning. The courses she teaches bridge science and practice, helping students apply evidence-based concepts to real-world professional settings.
