Physical Prime Around 35, Yet Exercise Slows the Decline

A Swedish population-based longitudinal study (SPAF) tracking participants from adolescence to age 63 finds that muscular endurance and aerobic capacity peak between ages 26–36, with muscle power peaking earlier (men ~27, women ~19). By 63, overall capacity can fall 30–48%. Regular physical activity slows the decline, and increasing activity in adulthood can boost capacity by about 10%, underscoring that while aging cannot be halted, its pace can be slowed. The study highlights youth activity and uses data from 1974 onward, published in the Journal of Cachexia, Sarcopenia and Muscle.