Research Examines Role of High-Intensity Interval Training in Healthy Aging
A study from the University of the Sunshine Coast suggests that high-intensity interval training (HIIT) may assist older adults in reducing body fat while preserving lean muscle mass. While other exercise intensities also contributed to fat loss, researchers observed that moderate-intensity training was associated with a slight decline in lean tissue. However, subsequent research indicates that the benefits of HIIT may vary depending on the population and the inclusion of other training methods, such as resistance exercise. Experts emphasize that while HIIT is a potential tool for healthy aging, it is not the only effective approach, and individuals should consider their personal fitness levels and medical history before starting demanding programs.
Key points
- A University of the Sunshine Coast study found HIIT helped older adults lose fat while retaining lean muscle.
- Moderate-intensity exercise reduced fat but was linked to a small decline in lean muscle mass.
- Lean mass includes muscle, water, and other tissues, meaning these findings do not directly measure muscle strength.
- Other 2026 studies suggest resistance training can also help preserve lean mass, regardless of aerobic intensity.
- A broad review found no consistent evidence that HIIT is superior to moderate-intensity exercise for all older adults.
What Happened
Researchers from the University of the Sunshine Coast conducted a six-month trial involving 123 healthy older adults to determine how exercise intensity affects body composition. Participants were assigned to high-intensity interval training (HIIT), moderate-intensity exercise, or a low-intensity comparison group. The study found that while all groups experienced some fat loss, only the HIIT group maintained lean tissue throughout the trial.
Lead author Dr. Grace Rose noted that while moderate training reduced fat mass, it also resulted in a small decline in lean muscle. HIIT, which involves alternating short bursts of demanding effort with recovery periods, appeared to provide a stronger signal to the body to retain muscle tissue.
Context
Maintaining muscle mass is critical for physical independence in older adults, aiding in balance, mobility, and daily activities. The researchers highlighted that weight loss alone does not necessarily improve body composition, as losing lean tissue alongside fat can be counterproductive for healthy aging.
Recent 2026 research has provided a more nuanced view of these findings. A study published in The Journals of Gerontology, Series A, found that when combined with resistance training, both HIIT and moderate-intensity exercise led to increased lean mass in older adults living with HIV, with no significant difference between the two groups. Additionally, a review in the Journal of Clinical Medicine concluded that while HIIT improves cardiovascular fitness, it is not consistently superior to moderate-intensity exercise across all metrics.
What's Next
Health organizations, including the Centers for Disease Control and Prevention, continue to recommend a balanced approach for adults over 65, incorporating aerobic exercise, muscle strengthening, and balance training. Experts advise that individuals who are currently inactive or have underlying medical conditions should consult with professionals before beginning high-intensity programs.
