As people age, their bodies naturally undergo several changes, including a decline in muscle mass and an increase in body fat. These changes can reduce strength and balance while also raising the risk of heart disease, diabetes, and falls. However, a new study suggests that one type of exercise may help older adults burn fat while protecting their muscles.

Researchers from the University of the Sunshine Coast in Australia found that High-Intensity Interval Training (HIIT) is an effective way for older adults to reduce body fat without losing muscle mass.

The study included 123 healthy adults between the ages of 65 and 85, with an average age of 72. Participants were divided into three groups based on exercise intensity: low, moderate, and high.

All participants exercised for 45 minutes, three times a week, over a period of six months. The results showed that both moderate- and high-intensity exercise reduced body fat. However, only those who performed HIIT were able to maintain their muscle mass while losing fat.

According to the study’s lead researcher, Dr. Grace Rose, all exercise intensities led to some reduction in body fat, but only high-intensity interval training successfully preserved muscle.

HIIT involves short bursts of vigorous exercise followed by brief periods of rest or light activity. For example, a person might walk briskly, cycle, or climb stairs for one minute, then rest or move slowly for one minute before repeating the cycle several times.

Experts say this style of exercise challenges both the heart and muscles, encouraging the body to burn fat while preserving lean muscle tissue.

The researchers also emphasized that body composition is more important than weight loss alone. Simply losing weight is not enough—reducing body fat while maintaining muscle mass is essential for healthy aging.

Although the findings are encouraging, experts caution that people with heart disease, joint problems, or other medical conditions should consult their healthcare provider before starting a HIIT program.

The researchers concluded that any form of physical activity is beneficial, but for older adults who can safely perform higher-intensity exercise, HIIT may be one of the best options for reducing fat while protecting muscle mass.