People exercise less on weight-loss drugs, research shows

Many GLP-1 users are getting smaller around the midsection. Unfortunately, their daily step counts are shrinking, too.

A recent study of 753 adults taking weight-loss drugs like Ozempic, Wegovy, and Mounjaro found that physical activity started to decline once treatment began.

• It’s one of the first large-scale analyses to track how exercise habits change once treatment begins by using data from real-world wearable devices.
• The team found average daily steps fell by ~10%, from 5,047 to 4,487, while moderate-to-vigorous exercise dropped from 28 mins/day to 22.

The findings, presented at the Endocrine Society's annual meeting this weekend, raise an important question: If the scale is moving in the right direction, why does exercise still matter?

It all comes down to muscle mass

While GLP-1 medications primarily target fat, they can also reduce lean muscle mass during rapid weight loss. But consistent exercise—especially resistance training—helps preserve patients’ strength, mobility, and long-term metabolic health.

Many doctors are also encouraging GLP-1 users to eat more protein to maintain their lean muscle mass while losing weight. Demand for whey protein has surged in recent months, with prices climbing to record highs and some suppliers reportedly sold out through the rest of 2026.

Looking ahead…The upcoming launch of a Medicare program providing weight-loss drugs for $50/month is expected to unleash pent-up demand for Wegovy, Zepbound, and other GLP-1 drugs. The program, set to begin July 1, is being hailed as one of the biggest drug rollouts in US history.