A new scientific statement from the American Heart Association (AHA) underscores that regular physical activity should be a "critical" component of any weight loss programme. The report, published in the journal Circulation, highlights that exercise—whether jogging, swimming, walking, or cycling—improves blood pressure, insulin sensitivity, cholesterol levels, and overall fitness in adults who are overweight or obese.
Physical Activity as a Cornerstone of Obesity Treatment
The AHA statement calls for a comprehensive treatment approach that places physical activity front and centre. It notes that even when combined with weight-loss medications or surgery, exercise adds significant health benefits. Professor Damon Swift, chair of the AHA writing group, emphasised that doctors often focus solely on weight loss to reduce heart disease risk, but encouraging physical activity should always be part of the care plan. "Physical activity delivers powerful heart and metabolic health gains even when the scale doesn't move," he said.
The Role of Exercise in Weight Loss and Muscle Preservation
While dietary changes remain the primary driver of weight loss, physical activity plays a powerful supporting role. Exercise can help people lose a little more weight, preserve important lean mass—especially with resistance training—and improve overall health. Professor Swift, from the University of Virginia, noted that when people lose weight by cutting calories, they often lose muscle as well. Studies show that adding exercise to dietary weight loss helps preserve more muscle compared with dieting alone. Strength or resistance training appears particularly effective, especially for middle-aged and older adults. Consuming at least the recommended daily amount of protein also aids in maintaining muscle while losing fat.
How Much Exercise Is Needed?
The statement highlights that exercise by itself rarely leads to clinically meaningful weight loss (5% or more of body weight) unless aerobic activity levels are quite high—at least 225 to 420 minutes per week. Fewer than 15% of people achieve significant weight loss through exercise alone. However, modest weight loss of around 3% to 5% of body weight is more achievable and still supports health benefits. The AHA recommends that adults get at least 150 minutes per week of moderate-intensity aerobic activity or 75 minutes per week of vigorous aerobic activity. Currently, only one in four adults and one in five youngsters aged six to 17 meet these national recommendations.
Long-Term Weight Maintenance
Maintaining weight loss is often more difficult than achieving it. The statement points to strong evidence that high levels of consistent physical activity—often 200 to 300 minutes per week of moderate-intensity activity—are associated with long-term weight-loss maintenance. However, even if people cannot reach those levels, it is still beneficial to maintain a regular schedule with some exercise and stay as active as possible. Professor Swift stressed that doing any physical activity is much better than doing nothing. "Many of the health benefits achieved from weight loss may be reversed if the weight is gained back. Physical activity can not only help maintain weight loss, it also may protect cardiovascular health even if some weight regain occurs," he added.
Individualised Treatment and Healthcare Support
The AHA statement emphasises that obesity treatment should be individually tailored and often requires a comprehensive, multipronged approach best achieved with guidance from a health professional. This includes setting realistic goals, staying motivated, and using evidence-based approaches such as medications, surgery, counselling, and digital tools. Dr Stacey Rosen, volunteer president of the AHA, noted that many people face challenges being active, including time constraints and limited access to safe or convenient ways to move. Addressing these barriers can help support healthier habits over time.
Professor Swift concluded: "For many people, lasting weight loss can feel out of reach. When movement is added as part of obesity care, it not only supports weight loss goals, but improves key health risk factors. Physical activity should be prescribed and prioritised for its cardiovascular and metabolic benefits in obesity treatment. Exercise can help you be healthier even if you don't lose weight."
