A landmark 47-year longitudinal study has revealed that humans reach their physical peak much earlier than many expect. Research conducted by the Karolinska Institute suggests that regardless of how often a person exercises, physical strength and fitness begin a natural decline starting around age 35.
While elite athletes are often the focus of such studies, this research tracked several hundred members of the general Swedish population from age 16 through 63. The findings indicate that while we cannot stop the biological clock, we maintain significant control over the speed of our physical decline.The study was published in the Journal of Cachexia, Sarcopenia and Muscle.
Key Findings on Physical Decline
The study tracked three major markers of physical health: aerobic capacity, muscular endurance, and muscle power.
- The Peak: For both men and women, aerobic capacity and endurance peaked between the ages of 26 and 36.
- The Initial Slide: Following the peak, performance dipped by a modest 0.3% to 0.6% annually.
- The Acceleration: As participants entered their 50s and 60s, the rate of decline sharpened significantly, reaching up to 2.5% per year.
- The Total Impact: By age 63, participants had lost between 30% and 48% of their peak physical capacity.
The Role of Physical Activity
Although exercise cannot delay the age at which we peak, it serves as a critical buffer. The study found that individuals who were active as teenagers entered adulthood with a higher "baseline" of fitness that lasted for decades.
Crucially, the researchers noted that it is never too late to intervene. Adults who increased their activity levels later in life saw an approximate 10% improvement in their physical capacity, effectively slowing the rate of deterioration.
Lead author Maria Westerstahl emphasized that while the biological mechanics of aging are inevitable, physical activity remains the most effective tool for maintaining mobility and independence well into older age.
