Mounjaro, Zepbound users gained strength with weight training, study finds

Adults taking tirzepatide lost less lean tissue and gained muscle strength when they combined the medication with resistance training, according to a new randomized trial led by researchers at the University of Western Australia.The findings, published November 9 in Nature Medicine, came from a 40-week trial that assigned 120 adults to either three resistance-training sessions a week or their usual activities. Everyone received tirzepatide.Tirzepatide is the active ingredient in Mounjaro and Zepbound. In the US, Mounjaro treats type 2 diabetes, while Zepbound is approved for weight management in eligible adults. The medication acts on two hormone receptors involved in appetite and food intake.Participants were men and postmenopausal women aged 50 to 70 who had obesity or overweight with a related health condition. They did not have type 2 diabetes. Both groups received general guidance on protein, fiber, and hydration.Both groups lost about 22 kilograms (roughly 49 pounds). Those who trained lost an average of 3.57 kg of lean soft tissue, compared with 4.67 kg among those receiving the medication alone. The difference was approximately 1.1 kg.Upper- and lower-body strength improved in the exercise group and declined in the medication-only group, including on tests involving the bench press and knee extension.Why strength matters during weight lossLean tissue includes muscle and other nonfat tissue. Lead investigator Prof.