Weight-loss medicines may be changing the way obesity is treated, but regular exercise remains the key to protecting heart health, according to a new study published in Nature Metabolism.

Researchers found that while weight-loss medication helped people maintain their weight after losing it, only those who exercised showed significant improvements in the health of their blood vessels and reductions in inflammation—two important factors linked to heart disease and stroke.

The study, led by researchers at the University of Copenhagen in Denmark, included 130 adults with severe obesity. All participants first completed an eight-week low-calorie diet and lost an average of around 30 pounds.

After the initial weight loss, the participants were followed for one year and divided into four groups. One group followed an exercise programme, another received weight-loss medication, a third combined exercise with medication, while the fourth received a placebo.

The results showed that people who exercised—whether or not they also took weight-loss medication—experienced healthier blood vessels and lower levels of inflammation. Researchers observed a 6% to 7% reduction in artery wall thickness, an important marker associated with the risk of heart disease and stroke.

Participants who combined exercise with weight-loss medication also achieved additional weight loss, suggesting that the two approaches can work together to improve overall obesity management.

However, people who relied only on medication or received a placebo did not experience the same cardiovascular benefits, indicating that medication alone may not be enough to protect heart health.

Lead researcher Dr. Signe Torekov, Professor of Biomedical Sciences at the University of Copenhagen, said the findings show that while weight-loss medicines are valuable for maintaining weight loss, they cannot replace the benefits of physical activity.

"Our study shows that medication helps maintain weight loss, but it is exercise—with or without medication—that improves vascular health," she said, adding that regular physical activity remains essential for protecting the heart and blood vessels.

Participants in the exercise groups completed an average of 150 minutes of physical activity each week, matching the amount currently recommended for adults in public health guidelines.

The researchers said the findings highlight the importance of combining lifestyle changes with modern obesity treatments to achieve the greatest long-term health benefits.