Weight loss medications (GLP-1 e.g. Ozempic) and Strength Training
: Why Muscle Matters During Weight Loss
GLP-1 medications such as semaglutide and tirzepatide have changed the way many people approach weight management.
GLP-1 medications are prescription drugs that mimic a natural gut hormone to lower blood sugar, slow stomach digestion, and reduce appetite. Primarily used to treat Type 2 diabetes and manage chronic weight, common examples include Ozempic (semaglutide), Trulicity (dulaglutide), and Wegovy (semaglutide)
They can be highly effective for reducing appetite, improving metabolic health and supporting meaningful weight loss. But there is one important piece of the puzzle that should not be overlooked: maintaining muscle.
When weight loss happens quickly, the body can lose more than fat. Research indicates that 20-40% of weight loss during treatment with GLP-1 based therapies may come from lean tissue, including skeletal muscle (1,2).
While some lean mass change is expected with any significant weight loss, preserving skeletal muscle is especially important because muscle supports strength, mobility, glucose control, metabolism, and long-term weight maintenance.
Why Strength Training Should Be Part of Your GLP-1 Plan
Strength training gives your body a clear signal to hold on to muscle while your weight is changing. It also helps you build confidence in movement, improve bone density, support joint health and maintain the strength needed for daily tasks like climbing stairs, carrying groceries, gardening or getting up from the floor.
Preserve muscle mass: Resistance training helps reduce the amount of muscle lost during weight loss.
Support metabolism: Muscle is active tissue that helps your body use energy and manage blood sugar.
Improve function: Stronger muscles make everyday movement easier and safer.
Protect long-term results: Maintaining strength can make it easier to sustain weight loss and stay active.
Improve confidence: A structured program helps you progress safely, especially if you are new to exercise or returning after a break.
What Should Strength Training Look Like?
For most people, a safe starting point is two to three strength sessions per week, focusing on major movement patterns such as squatting, hinging, pushing, pulling, carrying and core control. The goal is not to train as hard as possible on day one. The goal is to build consistency, learn good techniques and gradually increase challenge over time.
If you are using a GLP-1 medication, your exercise plan may need to consider changes in appetite, nausea, fatigue, hydration, and recovery. This is where an exercise physiologist can help. We can assess your current strength, movement quality, injury history, and health goals, then design a program that meets you where you are.
Strength Training Works Best with Smart Recovery
Because GLP-1 medications can reduce appetite, it can be harder to eat enough protein and overall energy to support muscle repair. Speak with your doctor or dietitian about nutrition targets that are appropriate for you. From an exercise perspective, prioritise regular strength training, adequate hydration, enough sleep, and gradual progression.
How Our Exercise Physiologists Can Help
Whether you are just starting a GLP-1 medication, already seeing weight changes or planning for long-term maintenance, our exercise physiologists can help you protect your strength while you work toward your health goals. We provide individualised assessments, safe strength programs, progress tracking and support that adapts as your body changes.
Ready to build strength alongside your weight-loss journey? Book an exercise physiology assessment and let us design a personalised program that supports muscle, movement and long-term health.
This article is general information only and is not a substitute for medical advice. Always speak with your prescribing doctor before changing medication use, and consult an appropriately qualified health professional before beginning a new exercise program.
References:
Karakasis P, Patoulias D, Fragakis N, Mantzoros CS. Effect of GLP-1 receptor agonists and co-agonists on body composition: systematic review and network meta-analysis. Metabolism. 2025;164:156113.
Neeland IJ, et al. Changes in lean body mass with glucagon-like peptide-1-based therapies and mitigation strategies. Diabetes Obes Metab. 2024;26(Suppl 4):16–27. doi:10.1111/dom.15728.
Written by Rachel Danaher, Accredited Exercise Physiologist, Mount Barker myPhysioSA
