Is a person on Mounjaro experiencing weight loss and wondering if they should still exercise?

In the quest for weight loss, a combination of medications and lifestyle changes is proving to be an effective approach. One such medication gaining attention is Mounjaro (Tirzepatide), a weight loss drug that works in conjunction with diet changes and increased physical activity.

These drugs, including Mounjaro and Ozempic, were originally developed to fight diabetes. They work by reducing appetite, leading to a calorie deficit and subsequent weight loss. The drugs suppress appetite by mimicking the hormone GLP-1 (glucagon-like peptide-1).

GLP-1, a key player in how the body processes food, plays a significant role in this process. When the body is in a calorie deficit, especially driven by eating less, it taps stored fat for energy. However, it's essential to note that these drugs do not burn fat directly; instead, they enable healthier food choices and create a calorie deficit.

Exercise is crucial in this weight loss journey, particularly when on GLP-1 medications. PT Adam Enaz explains that these drugs work by suppressing appetite rather than directly increasing fat burning. Therefore, physical activity becomes even more important for maintaining muscle mass, metabolism, and overall weight management.

Combining cardio with weight training supports weight loss, while providing enough stimulus to ensure muscles still grow. PT Farren Morgan echoes this sentiment, stating that physical activity is essential to preserve muscle mass and maintain metabolism while on GLP-1 medications like semaglutide.

A structured approach to maintaining muscle mass and fitness during GLP-1 use is recommended. This approach includes daily low-intensity movement, transitioning to resistance training (60 to 90 minutes per week), and progressing to regular aerobic exercise (30 to 60 minutes per day).

Research supports the benefits of combining weight loss drugs with structured exercise. In one trial, people who combined liraglutide with structured exercise kept far more of the weight off after a year compared to those who did not exercise. Those who combine weight loss drugs with structured exercise are more likely to lose a greater proportion of fat, hold onto more muscle, and keep the weight off once the medication stops.

Nutritionist Gráinne Quinn Jordan asserts that exercise and medication together give the best outcomes for weight loss. A July 2025 report published in the Journal of the American Medical Association further emphasises this, suggesting a structured approach to maintaining muscle mass and fitness during GLP-1 use.

While the amount of exercise necessary while on weight loss drugs is not clear-cut, it is not advisable to stop exercising or to engage in harmful exercise levels. The key is to find a balanced and sustainable approach that works for each individual. The drug helps with weight loss, but movement makes the difference long term.