GLP-1 medications have changed the way many people approach weight management.

But when body weight decreases, not everything lost is necessarily body fat. Significant weight loss can also include some lean tissue, including muscle.

A 2026 systematic review of randomised trials found that lean mass represented a meaningful proportion of weight lost with incretin-based therapies such as semaglutide and tirzepatide. The same review found the most favourable lean-mass preservation in interventions that incorporated resistance training.

For people using GLP-1 medication, that makes strength training an important part of the bigger picture.

Why Maintaining Muscle Matters

Muscle isn't just about appearance. It contributes to strength, mobility, balance and your ability to perform everyday tasks. For adults in their 30s, 40s and 50s, maintaining muscle while losing weight can help ensure that becoming lighter doesn't also mean becoming unnecessarily weaker.

Resistance exercise during weight loss has been shown to reduce the loss of fat-free mass and improve muscular strength compared with dietary weight loss alone.

Strength training also provides mechanical loading to the musculoskeletal system, which is one reason muscle-strengthening activity forms part of international recommendations for maintaining muscle and bone health.

You Don't Need Extreme Exercise

Someone losing weight on GLP-1 medication does not automatically need high-intensity workouts, exhausting circuits or aggressive exercise programs. A more sensible approach is structured resistance training that can be adjusted as strength, energy levels and ability change.

At Rosebery Personal Training, GLP-1 clients train primarily with controlled pin-loaded and plate-loaded machines. Resistance can be adjusted to suit the individual, with coaching focused on technique and gradual progression.

That might include exercises for:

• Legs and glutes
• Back
• Chest
• Shoulders
• Arms
• Core and supporting muscles

The objective isn't to see how exhausted you can become. It is to provide enough resistance to challenge the muscles and gradually improve strength.

Why Supervision Can Help

Starting strength training can be daunting even without the added changes that can accompany substantial weight loss. An experienced coach can select appropriate exercises, set the resistance, watch technique and adjust the program as you progress.

Rosebery PT sessions run for a full 60 minutes, beginning with 30 minutes of dedicated one-on-one coaching followed by 30 minutes of supervised strength training.

For someone who hasn't exercised for years or has never used resistance equipment before, having that guidance can make training much easier to understand.

What About Nutrition?

Nutrition remains important while losing weight, particularly when appetite and food intake are changing.Adequate nutrition and protein intake are among the

strategies discussed in current research for supporting lean mass during

significant weight loss.

Individual dietary needs vary, however, particularly for anyone managing medical conditions or medication.

Rosebery PT can support the training and nutrition side of a body transformation program, but GLP-1 medication itself should be prescribed and managed by an appropriately qualified healthcare professional. Rosebery PT does not prescribe, supply or manage GLP-1 medication.

The Goal Is Stronger Weight Loss

Successful weight management isn't simply about making the number on the scales smaller. For many adults, the better goal is to lose unwanted body fat while doing what you reasonably can to maintain strength, muscle and physical function.

Resistance training gives your muscles a reason to keep working while your body weight changes. You don't need to train like an athlete. You simply need a sensible program, appropriate resistance, good technique and consistent progression.

Using a GLP-1 and unsure where to begin with strength training? Talk to Rosebery PT about supervised training in our private Rosebery studio.