Losing weight after 65 can come with an unwanted trade-off: losing muscle along with body fat. But researchers who compared three exercise programs discovered that one approach helped older adults avoid that problem.
High-intensity interval training (HIIT) preserved lean mass while reducing fat, according to a University of the Sunshine Coast study published in Maturitas. Moderate-intensity exercise also reduced fat, but participants experienced a small decline in lean tissue.
The distinction matters because maintaining muscle becomes increasingly important for mobility and independence with age.
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Why One Workout Outperformed the Others
Researchers followed 123 healthy adults averaging 72 years old. Participants completed three supervised, 45-minute sessions weekly for six months, using high-, moderate-, or low-intensity exercise.
“We found that high, medium and low intensity exercises all led to modest fat loss but only HIIT retained lean muscle,” lead author and exercise physiologist Grace Rose, PhD, told ScienceDaily.
The researchers also reported improvements in abdominal fat measurements, although the changes were modest.
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What Makes HIIT Different After 65?
Unlike steady-paced cardio, HIIT alternates demanding exercise with recovery periods.
University of the Sunshine Coast associate professor of physiology Mia Schaumberg, PhD, explained the potential advantage:
“HIIT likely works better because it puts more stress on the muscles, giving the body a stronger signal to keep muscle tissue rather than lose it.”
That doesn’t mean older adults need exhausting workouts every day. The study involved supervised sessions, individualized exercise intensity, and planned recovery.
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What the Findings Mean for Your Workout
The researchers cautioned that improvements were relatively small and not clearly clinically meaningful compared with lower-intensity exercise.
Another limitation: Body-composition scans measured lean tissue, not muscle strength directly. Preserving lean mass doesn’t automatically prove greater strength or better daily function.
For older adults interested in HIIT, the practical approach is to build fitness gradually, choose manageable intervals, and consider medical guidance before beginning vigorous exercise.
The takeaway: Don’t judge a fat-loss program by the scale alone. Protecting lean tissue deserves attention, too.
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