New research indicates that patients prescribed GLP-1 medications—such as Ozempic, Wegovy, and Mounjaro—may experience a decline in physical activity levels shortly after beginning treatment. Data presented at the Endocrine Society’s annual meeting, ENDO 2026, reveals that average daily step counts dropped from 5,047 to 4,487 among study participants, while moderate-to-vigorous physical activity (MVPA) fell from 28 to 22 minutes per day. These findings suggest that weight loss success driven by medication does not automatically translate into a more active lifestyle.
Why does physical activity decrease on GLP-1 therapy?
The reduction in movement is often linked to the physical side effects of the medication, primarily fatigue. According to Dr. Mir Ali, medical director of the MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center, patients frequently report that the weight loss process feels physically draining, which turns routine exercise into a significant chore. While the study—which analyzed Fitbit data from 753 participants—did not identify age or prior heart conditions as primary drivers of this decline, it did highlight that males and individuals with musculoskeletal pain showed the most pronounced drops in activity.
The study found no evidence that the weight loss achieved through GLP-1 medications encourages users to become more active. Instead, the data suggests a potential “sedentary trap” where users move less as the medication takes effect.
What are the risks of reduced movement during weight loss?
A sedentary lifestyle during medical weight loss can undermine long-term health goals. Dr. Ali warns that a lack of exercise during this period can lead to accelerated muscle loss, heightened fatigue, and results that fall short of a patient’s goals. Prior research consistently demonstrates that maintaining muscle mass is vital for metabolic health, and exercise is the primary tool for preserving that tissue while fat stores decrease.
Pro Tips for Maintaining Activity Levels
- Consistency over intensity: You don’t need to train like an athlete. Aim for 30 minutes of movement, five days a week.
- Break it up: If a 30-minute block feels too daunting, split your exercise into three 10-minute segments throughout the day.
- Prioritize resistance: Combine aerobic activity with resistance training to specifically target muscle preservation.
How do experts recommend balancing medication and exercise?
Dr. Sajana Maharjan, a board-certified internist at HSHS St. John’s Hospital and lead author of the study, emphasizes that exercise must remain a non-negotiable component of a weight management plan. She argues that clinicians must provide targeted interventions to encourage physical activity alongside medication. Relying solely on dietary changes may lead to weight loss, but it fails to build the cardiorespiratory fitness and mental well-being that regular movement provides.
Frequently Asked Questions
Does everyone lose muscle mass on GLP-1s?
Muscle loss is a common risk when weight is lost rapidly. However, combining GLP-1 treatment with consistent resistance training and adequate protein intake can help mitigate this effect, according to general clinical guidelines.
Is walking enough for weight maintenance?
Yes, walking provides significant health benefits. Dr. Ali notes that even low-intensity, consistent movement is far better than a sedentary lifestyle for preserving metabolic function.
Should I stop my medication if I feel too tired to exercise?
No. Patients should consult their healthcare provider to adjust their treatment plan or activity goals rather than stopping medication abruptly. Managing side effects like fatigue is a standard part of clinical oversight for these drugs.
Are you currently managing a weight loss plan with GLP-1 medication? Share your experience with balancing movement and treatment in the comments below, or sign up for our newsletter for the latest updates on metabolic health research.
