Overview

• GLP-1 receptor agonists markedly reduce body weight and fat mass but yield no clear improvement in VO2max, a key measure of cardiorespiratory fitness.
• Patients lose 25–40% of total weight as fat-free mass, with muscle accounting for up to half of that loss.
• Researchers caution that reductions in lean muscle may elevate risks of cardiovascular disease, increased mortality and diminished quality of life.
• Experts recommend screening for malnutrition and low muscle mass before treatment and prescribing structured exercise to mitigate muscle depletion.
• The review calls for further research into nutritional supplements, adjunctive medications and robust trials to enhance the cardiorespiratory benefits of GLP-1 therapies.