Researchers have recently shed light on how exercise benefits the body on a cellular level. What’s more, they’ve determined a type of exercise that’s best for boosting cell health.

Published in Cell Metabolism (2017; 25 [3], 581–92), the study included 36 men and 36 women categorized as “young” (aged 18–30) or “older” (aged 65–80). Each participant was assigned to one of three training programs for 12 weeks: high-intensity interval training (HIIT) on an indoor bike; strength training with weights; or a combination of the two. Study leaders took muscle biopsies from the volunteers—who also underwent lean-mass and insulin-sensitivity tests—and then compared the results with those from a sedentary control group.

Data showed that the exercise groups experienced improvements in cellular function and in the ability of mitochondria to generate energy; this adds further evidence that exercise does in fact slow the aging process at a cellular level. Muscle mass and insulin sensitivity improved
with all three training protocols. However, outcomes did vary.

“HIIT revealed a more robust increase in gene transcripts than other exercise modalities, particularly in older adults,” the authors explained. Specifically, HIIT increased mitochondrial capacity by 49% in the “young” group and 69% in the “older” group.

The authors added, “HIIT reversed many age-related differences in the proteome, particularly of mitochondrialproteins in concert with increased mitochondrial protein synthesis.”

For best benefit, according to the study, a combination of strength training and HIIT is recommended. While HIIT proved best at improving cellular health, it was less effective at increasing strength and muscle mass than the strength training protocol.

“We encourage everyone to exercise regularly, but the take-home message
for aging adults is that supervised high-intensity training is probably best, because, both metabolically and at the molecular level, it confers the most benefits,” concluded K. Sreekumaran Nair, MD, PhD, a Mayo Clinic endocrinologist and senior researcher on the study.