A new study using wearable device data found that people who start GLP-1 weight-loss medications like Ozempic and Wegovy actually move less once treatment begins — not more. Among 753 adults tracked in the NIH's All of Us Research Program, daily step counts fell from 5,047 to 4,487 — an 11% drop — while moderate-to-vigorous exercise declined from 28 to 22 minutes per day.
The findings, presented at ENDO 2026, the Endocrine Society's annual meeting in Chicago, challenge the common assumption that losing weight naturally encourages people to be more active. Lead researcher Dr. Sajana Maharjan of HSHS St. John's Hospital warned that "exercise cannot be optional" for people on these medications, since GLP-1 drugs erode muscle mass alongside fat — making inactivity doubly harmful.
The study covered 1,950 adults prescribed GLP-1 drugs including semaglutide (Ozempic, Wegovy), tirzepatide (Mounjaro, Zepbound), liraglutide, and dulaglutide. The steepest activity decline occurred in men and in those with musculoskeletal pain. Researchers called for targeted interventions to keep patients moving alongside their medication regimens.