Weight-loss medications like GLP-1 receptor agonists have transformed obesity care in recent years by helping millions reduce appetite and shed excess weight. These drugs like Ozempic, Wegovy and Mounjaro, many of whom were originally developed for type 2 diabetes and now widely used for obesity treatment, mimic the body's own glucagon-like peptide-1 hormone to suppress hunger and improve metabolic control. Meta-analyses have consistently shown that GLP-1 receptor agonists produce significantly greater weight loss than placebo or standard care across diverse populations with or without diabetes. However, recent clinical evidence suggests that weight loss alone may not translate into real improvements in physical fitness and functional capacity unless paired with structured exercise.
A new secondary analysis of a randomized controlled trial published in Sports Medicine shows that adults with obesity who lost weight either with a GLP-1 drug (liraglutide) or placebo improved physical fitness only if they also followed a formal exercise program. In contrast, participants who took liraglutide without structured physical activity did not show meaningful gains in cardiorespiratory fitness or functional mobility, despite significant weight loss.
This finding highlights a critical nuance that many jumping on the Ozempic trend have missed. Losing kilograms on medication is not the same as improving fitness or long-term health, and even that weight loss won't happen at the rate you're dreaming of without daily exercise. For sustainable outcomes and better functional health, combining pharmacotherapy with regular exercise may be essential.
GLP-1 Medications: Weight Loss Without Fitness Gains?
What GLP-1 Receptor Agonists Do
GLP-1 receptor agonists, such as liraglutide, semaglutide, and others, improve weight loss by reducing appetite and enhancing satiety. Systematic reviews of randomized controlled trials involving thousands of participants show that these drugs lead to a significantly greater reduction in body weight than controls, along with metabolic benefits such as lowered blood pressure and improved glycaemic control. Additionally, genetic evidence suggests GLP-1-based therapies preferentially reduce body fat more than lean mass, further confirming their effectiveness in altering body composition.
Trial Design: Exercise vs. Medication Alone
In the Sports Medicine analysis, adults with obesity first underwent an eight-week very low-calorie diet to achieve a minimum of 5% weight loss. They were then randomized into four groups for a 52-week intervention:
- Placebo with usual activity
- Placebo plus structured exercise
- Liraglutide with usual activity
- Liraglutide plus structured exercise
Exercise included supervised cycling and moderate-to-vigorous aerobic activity meeting World Health Organization (WHO) physical activity guidelines.
Also Read: Ozempic Enters India: Diabetes Drug, Not A Miracle Fix, Novo Nordisk MD To NDTV
Fitness Outcomes: Why Exercise Matters
The trial's key finding was clear. Structured exercise, not drug therapy alone, drove improvements in physical fitness and functional mobility.
- Participants in both exercise groups (with or without liraglutide) exhibited significant gains in cardiorespiratory fitness (measured by peak oxygen consumption relative to fat-free mass).
- They also showed faster stair-climb performance, reflecting better mobility and lower-limb function.
- By contrast, the group receiving liraglutide without structured exercise did not improve fitness measures despite comparable weight loss.
- These results suggest that while GLP-1 drugs help reduce body weight, they do not replace the cardiovascular and functional benefits of physical activity.
Muscle Strength and Body Composition
Interestingly, absolute muscle strength remained stable across all groups, indicating that neither exercise nor medication adversely affected raw muscle capacity. However, exercise enhanced strength relative to body weight, an important marker of functional ability in daily life.
The newest trial evidence makes one point clear. GLP-1 drugs like Ozempic, Mounjaro and Wegovy can help people lose weight, but physical fitness gains require structured exercise. Medications alone are a powerful tool for reducing body weight, yet they fall short in improving functional capacity, cardiorespiratory health, and mobility without physical activity. For individuals seeking sustainable weight management and comprehensive health benefits, combining pharmacotherapy with regular, structured exercise, including aerobic and resistance training, is essential. This integrated strategy aligns with global clinical recommendations for obesity and chronic disease management, underscoring the enduring importance of physical activity even in an era of advanced medical therapies.
Disclaimer: This content, including advice, provides generic information only. It is in no way a substitute for a qualified medical opinion. Always consult a specialist or your own doctor for more information. NDTV does not claim responsibility for this information.
