A 47-year longitudinal study of over 400 individuals in Sweden has revealed that peak physical capacity occurs earlier in life than commonly believed, with a gradual decline beginning as early as age 35. The research, which tracked participants from age 16 to 63, measured changes in aerobic capacity, muscular endurance, and muscular power.
The study, conducted by researchers following a Swedish population cohort born in 1958, found that both muscular endurance and maximal aerobic capacity peaked between the ages of 26 and 36. Following this peak, a gradual decline set in, initially at a rate of 0.3% to 0.6% per year, which later accelerated to as much as 2.5% annually. Notably, the rate of decline did not differ between men and women.
Muscular power, as measured by the Sargent jump test, peaked slightly earlier, at age 27 for men and age 19 for women. Researchers observed a marked increase in the variability of physical performance with age. From adolescence to age 63, the variance in relative aerobic capacity increased 25-fold, jump height nearly 5-fold, and muscular endurance threefold.
The initial rate of decline in physical capacity was relatively small, ranging from 0.2% to 0.5% per year. However, this rate increased with age, reaching 2.2% per year in later years, again without any observed difference between sexes. The decline in physical capacity from peak performance to age 63 ranged from 30% to 48%.
The findings, published in multiple journals including PubMed and Wiley Online Library, suggest that the processes underlying muscle dysfunction may begin decades before they become clinically relevant. Previous research on elite athletes had indicated a similar pattern, with peak performance typically occurring before age 35 despite continued training. This new study confirms that this pattern extends to the general population.
Researchers emphasize that while the decline in physical capacity appears inevitable, maintaining physical activity may influence the rate of deterioration. The study did not specifically investigate the impact of exercise interventions, but suggests that continued activity could potentially mitigate the speed of decline. A related study analyzing data from nearly 1 million New York City youth found an inverse relationship between weight status, aerobic capacity, and muscular strength and endurance, with the most significant effects observed for aerobic capacity.
The study’s methodology involved linear mixed models to estimate age- and sex-specific changes in physical capacity over the study period. The cohort included 427 individuals, with 48% being women. The research builds on previous studies that often relied on cross-sectional data, offering a more comprehensive understanding of long-term changes in physical performance.
