By Randall Cooper, Sports & Exercise Physiotherapist
There’s a lot of noise around GLP-1 medications like Ozempic and Wegovy. Originally developed for diabetes, they’re now prescribed widely for weight loss, and increasingly showing up in athlete and active populations.
In Episode 9 of Exercise Matters, I unpack what these drugs actually do, how they work, and whether they help or hinder performance, injury recovery, and training gains.
🎧 Listen to the full episode here
What Is Ozempic (and Other GLP-1 Drugs)?
GLP-1 receptor agonists mimic a gut hormone that helps regulate insulin and satiety. They reduce appetite, promote weight loss, and improve metabolic health.
Ozempic (semaglutide) became mainstream after the STEP 1 trial showed 15% weight loss in non-diabetic adults. That result changed everything - these meds are no longer just for diabetes.
The Upside
There are performance advantages, especially for endurance athletes or those with joint issues:
- Better power-to-weight ratio
- Less joint load (useful for those with osteoarthritis)
- Lower inflammation markers in some studies
The STEP 9 trial even showed less knee pain in overweight adults using semaglutide. So there’s legitimate therapeutic benefit here.
But There Are Trade-Offs
The main issue: muscle loss. When people lose weight on GLP-1 drugs, up to 40% of that loss can be lean mass if not combined with exercise and protein intake. That’s a massive concern for strength, power, and rehab outcomes.
Other side effects:
- Fatigue and low energy availability
- GI symptoms like nausea and appetite suppression
- Possible bone density reduction with long-term use
These are real risks for athletes and active people.
Mitigation: Resistance Training and Protein
The muscle loss isn’t inevitable. When combined with:
- Strength training
- Adequate protein intake
- Micronutrient support (e.g., calcium, vitamin D)
… the negative effects can be minimised. But many people on these meds aren’t doing enough in those areas.
What About Rehab?
Weight loss can help reduce joint load and improve function. But if the weight loss includes muscle? That’s a problem. Especially in:
- ACL rehab
- Knee OA
- Post-op recovery
We want to reduce joint stress, not compromise tissue integrity or delay strength gains.
Bottom Line
GLP-1 medications like Ozempic and Wegovy are effective, but not without cost. If you’re an athlete or active individual considering them, understand the trade-offs. You might be lighter, but you may also be weaker and slower if you don’t manage the process properly.
