GLP-1 Medications and Exercise: What You Should Know About Your Energy and Performance

As a sports and family medicine doctor, I’ve had many patients ask: “Will these medications help or hurt my workouts?” Let's dive into the discussion!

GLP-1 Medications and Appetite: Helpful, But Sometimes Too Effective

These medications work by slowing digestion, stabilizing blood sugar, and reducing appetite. For many people, that’s a huge win—especially if they’ve struggled with overeating or energy crashes. But the decrease in appetite can sometimes lead to under-fueling, especially if you’re active.

Without enough calories—especially carbohydrates and protein—your body may not have the energy it needs to support:

• Endurance

• Strength

• Recovery

• Lean muscle maintenance

Some patients on GLP-1 meds report early fatigue, low energy during workouts, or longer recovery times—often tied to undernutrition rather than the drug itself.

Nausea and GI Issues Can Disrupt Exercise

Nausea, reflux, or bloating—common side effects in the first few weeks of GLP-1 therapy—can also make exercise uncomfortable. This may cause people to move less, skip workouts, or avoid more intense training, at least temporarily.

Weight Loss May Improve Movement and Joint Health

On the flip side, losing excess body weight often leads to improved mobility, joint comfort, and cardiovascular function. Patients with knee pain or back pain frequently find they can move more comfortably and consistently after even modest weight loss.

So while some people may experience an initial dip in performance, others report feeling lighter, faster, and more motivated after starting treatment.

What About Muscle Strength?

As we covered in a related blog, GLP-1 medications may lead to lean muscle loss if weight loss is too rapid or not supported by strength training and adequate protein intake. Muscle is key for long-term metabolic health and exercise performance, so the goal is to preserve or even build muscle while on medication.

Tips to Support Exercise While Using GLP-1 Medications

If you’re taking a GLP-1 medication and want to stay active (which I strongly encourage), here are some strategies:

1. Eat with Intention
   Even if you’re not hungry, fuel your workouts with light, balanced meals or snacks that include carbs and protein.

2. Hydrate Well
   Slowed digestion and reduced thirst cues can lead to underhydration. This can hurt performance and increase the risk of cramps or fatigue.

3. Time Workouts Thoughtfully
   Avoid high-intensity sessions immediately after taking your medication, especially if you tend to experience GI symptoms.

4. Prioritize Strength Training
   Incorporating resistance work 2–3 times a week helps maintain lean muscle and boosts long-term exercise capacity.

5. Listen to Your Body
   Start slow if you’re new to movement. Some people need a few weeks for their body to adjust to the medication before pushing intensity.

Final Thoughts

GLP-1 medications can be powerful allies in managing weight and blood sugar, but they’re most effective when used as part of a comprehensive lifestyle approach—one that includes movement, strength, nutrition, and recovery.

If you’re starting one of these medications and want to keep—or improve—your fitness, talk to your healthcare team about an exercise plan tailored to your body and your goals. With the right support, you can feel stronger, not weaker, on your journey.

At Princeton Sports and Family Medicine, P.C., our doctors specialize in sports medicine services, including weight loss, exercise counseling and physician services to assess your risk for injury and assist in your performance goals.

Call or click to book a session with our professionals at Princeton Sports and Family Medicine, P.C. In addition to problem-focused visits, we offer sports performance evaluations to stop problems before they start. Plan your visit today!

Author

Peter Wenger, MD Peter C. Wenger, MD, is an orthopedic and non-operative sports injury specialist at Princeton Sports and Family Medicine, P.C., in Lawrenceville, New Jersey. He is board certified in both family medicine and sports medicine. Dr. Wenger brings a unique approach to sports medicine care with his comprehensive understanding of family medicine, sports medicine, and surgery. As a multisport athlete himself, he understands a patient’s desire to safely return to their sport.