Researchers tracked physical activity in nearly 3,900 older Americans over 12 years and measured biological aging via three DNA methylation clocks. Physically active participants showed significantly younger biological ages — up to 1.70 years younger by PhenoAge and 1.26 years younger by GrimAge — compared to inactive peers. A novel life-course modeling approach revealed that both cumulative lifetime exercise habits and current activity levels were the strongest predictors of slower biological aging. Effects persisted after adjusting for BMI, chronic disease, and mobility. The findings suggest that consistent moderate-to-vigorous physical activity is one of the most reliable lifestyle factors for slowing epigenetic aging in older adults.
