Strength Training Helps Protect Muscle During Weight-Loss Treatment, Study Finds
10 Nov 2026
The University of Western Australia research team published the findings in Nature Medicine.It highlights the importance of exercise alongside GLP-1 medication to support muscle health during significant weight loss.
The Tirzepatide and Resistance Exercise (T-REx) study followed 120 men and post-menopausal women aged between 50 and 70 over 40 weeks. Participants were either living with obesity or had excess weight alongside a related health condition, excluding type 2 diabetes.
All participants received tirzepatide for weight management. Half also completed resistance training three times a week, while everyone received general advice about protein, fibre and hydration.
Both groups lost a similar amount of weight. Those who exercised lost an average of 22.8 kg, compared with 22.61 kg in the group that did not do resistance training.
However, the results showed a clear difference in muscle health. Participants who completed strength training lost 25% less lean tissue, including muscle, and improved their upper and lower body strength by 10%.
In comparison, participants who did not exercise experienced a 10% decline in strength.
Lead researcher Professor Danny Green said resistance training could not completely prevent muscle loss during weight reduction. However, maintaining and improving strength was particularly important for reducing the risk of frailty.
Researchers also used DEXA scans every eight weeks to track changes in body composition. This helped them understand how quickly weight, fat and lean tissue changed during treatment.
Professor Green said GPs could use simple assessments during consultations to monitor patients' muscle strength and physical function.
These include asking patients about everyday activities, checking hand grip strength and carrying out a sit-to-stand test. Both physical tests can be completed in less than a minute.
He also highlighted the importance of identifying patients who may be approaching frailty, rather than waiting until significant physical weakness develops.
For patients with concerns about muscle strength or muscle mass, Professor Green suggested referral to an accredited exercise physiologist.
He said resistance training was accessible, relatively inexpensive and could be included in routine primary care.
Professor Green added that weight-loss medications are only one part of treatment, with GPs playing an important role in supporting patients through a broader approach to health and wellbeing.
Strength Training Helps Protect Muscle During Weight-Loss Treatment, Study Finds
Source: Nature Medicine – Tirzepatide and Resistance Exercise (T-REx) Study.