If you’re on Ozempic, Wegovy, Mounjaro or a similar medication, you’ve probably been told it will help you lose weight. What you might not have been told is what else you could be losing along with it — and what that means for how you exercise while you’re on it.
We hear a version of this in clinic more and more: “The weight’s coming off, so I must be doing everything right.” It’s an understandable assumption. It’s also not the whole picture.
What the Research Is Actually Showing
A study presented at ENDO 2026, the Endocrine Society’s annual meeting, tracked 753 adults who started GLP-1 medications, using wearable fitness tracker data from the NIH’s All of Us Research Program. What they found surprised even the researchers: people became less active after starting these medications, not more.
Daily steps dropped from an average of 5,047 to 4,487. Moderate-to-vigorous activity fell from 28 minutes a day to 22. The biggest drops were seen in men and in people already dealing with joint or muscle pain.
As lead researcher Dr Sajana Maharjan put it: “Exercise cannot be optional for people taking these medications.”
Why This Matters More Than the Number on the Scale
GLP-1/GIP medications don’t just target fat. They reduce lean muscle mass too — and if activity levels are dropping at the same time, that muscle loss isn’t being offset by anything. You can end up lighter, but weaker, with less muscle doing more of the day-to-day work your body relies on.
This isn’t about willpower. The research is clear that weight loss on its own doesn’t naturally increase how much people move — if anything, the opposite tends to happen. Which means staying active on these medications has to be something you build in deliberately, not something you assume will follow along.
Why This Is Such a Big Conversation Right Now
This isn’t a niche issue. A UNSW study released in 2026 found that roughly half a million Australians are now regularly using GLP-1 medicines, with usage climbing sharply — from around 58,000 units sold in 2020 to 500,000 in 2025. If you’re on one of these medications, you’re part of a genuinely large and fast-growing group, and the exercise side of the conversation hasn’t caught up with how many people it now affects.
What “Exercise Isn’t Optional” Actually Looks Like
This doesn’t mean pushing through exhaustion or adding intense workouts on top of a big lifestyle change. It means a program built specifically around preserving and building strength while your body is going through this shift — one that accounts for changes in appetite, energy and recovery that often come with these medications.
At Optimum, that starts with resistance training prioritised over pure cardio, because it’s the most effective tool for protecting and building muscle. It’s paired with a plan that’s realistic for your energy levels on any given week, and adjusted as you go — not a generic program pulled off a template.
Where to Start
You don’t need to have this figured out on your own. This is exactly the kind of situation an Accredited Exercise Physiologist is trained for: understanding what’s happening in your body on these medications, and building a program that works with it rather than ignoring it.
To help make sense of it all, we’ve put together a free guide to exercising safely on GLP-1/GIP medications — covering what the research actually shows, what a supportive program looks like, and practical starting points you can use right away.
Download the free guide, so you can protect your strength and hold onto your results — without losing muscle, and without feeling lost on where to start. Click on the link, go to our resources section on our website, or call us on 8873 0628 for a chat about what a program built around your situation could look like.
