Ozempic Users Took Fewer Steps After Starting

The Finding

People taking GLP-1 weight-loss drugs moved less after starting the medications, according to an analysis of Fitbit data. Average daily step counts among users dropped from 5,047 to 4,487, while daily moderate-to-vigorous activity fell from 28 minutes to 22.

That works out to roughly 560 fewer steps and six fewer minutes of meaningful exercise per day, measured before and after participants began their prescriptions. Because the comparison is within the same people over time, each participant effectively served as their own baseline, which is what lets the analysis frame the change as a shift that accompanied starting the drug rather than a difference between two separate groups.

Who Produced the Data

The analysis was conducted by doctors at HSHS Saint John’s Hospital in Illinois and collaborators, who examined Fitbit data from people with obesity who were prescribed a GLP-1 medication. The study focused on 753 volunteers who had Fitbit activity data available both before and after their prescriptions began.

Using wearable data rather than self-reported activity is a notable feature of the design. Step counts and activity minutes recorded by a device sidestep the recall errors that often complicate diet-and-exercise research. When people are asked to estimate how much they moved, answers tend to drift toward what they intended or what sounds reasonable; a wearable simply logs what happened, which is why this kind of data is treated as a more objective record of behavior.

Which Drugs Were Involved

The medications studied included the newest drugs on the market, such as semaglutide and tirzepatide, as well as older medications liraglutide and dulaglutide. That range means the pattern was not tied to a single product but appeared across the class.

The breadth matters for interpretation. A drop seen across multiple GLP-1 medications points to something about how the drugs affect behavior or energy, rather than a quirk of one formulation. When a single product shows an effect, it can be hard to separate the drug from the people who happen to take it; seeing the same direction across several medications in the class makes the pattern harder to dismiss as a one-off.

Why It Matters

The concern is not the weight loss itself but what happens to the body alongside it. Because these drugs can reduce muscle mass along with fat, a decline in physical activity raises questions about preserving strength and long-term health.

The researchers were direct about the implication, concluding that “exercise cannot be optional for people taking these medications.” In other words, the activity drop they measured is the opposite of what would best protect muscle during rapid weight loss.

What to Keep in Mind

The research was set to be presented at ENDO 2026, the Endocrine Society’s annual meeting, and had not yet been published in a peer-reviewed journal at the time of reporting. That status means the findings should be read as preliminary pending full review.

Preliminary does not mean unfounded, but it does mean the results have not yet cleared the scrutiny that peer review provides. Conference presentations let researchers share results early so other experts can react, while peer review is the slower process in which independent specialists examine the methods and analysis before formal publication. Until that step is complete, the figures are best treated as a strong early signal rather than a finished conclusion.

Where the Numbers Land

The measured declines are modest in absolute terms but consistent in direction across the group studied. For people on these medications, the takeaway from the researchers is to treat activity as part of the treatment rather than an optional add-on.

According to the analysis, daily steps among the 753 GLP-1 users fell from an average of 5,047 to 4,487 after starting treatment, with moderate-to-vigorous activity declining from 28 minutes a day to 22.

References: Releases | Ozempic Users Are Skimping Out On Exercise Study Finds