Scientists discover age you hit ‘peak physical fitness’

A comprehensive 47-year study has revealed the precise age at which people hit their physical fitness peak and when decline begins. In a positive development, researchers also found that it’s never too late to start, with adults who begin exercising later in life still capable of boosting their physical capacity by up to 10%.

The findings contained a concerning revelation: physical fitness begins to deteriorate at 35, considerably earlier than many might expect. The Karolinska Institutet research discovered that physical capacity and muscle endurance reached their highest point between the ages of 26 and 36 for both men and women.

However, beyond the age of 35, fitness and strength began declining, irrespective of how much people exercised before. The research cautioned that people leading inactive lifestyles could face a substantial drop in physical function after hitting their fitness peak.

Maintaining physical activity, whether begun during teenage years or later in adulthood, was linked to improved outcomes. Between the ages 35 and 63, physical capacity dropped by as much as 48%. This decline started slowly but accelerated with advancing age.

Yet despite this discovery, researchers uncovered that people who only began exercising during these years still managed to enhance their physical capacity by approximately 5-10%. This underscores that exercise remains a crucial element for maintaining health at any age.

Maria Westerståhl, a lecturer at the Department of Laboratory Medicine and the study’s lead author, explained: « It is never too late to start moving. Our study shows that physical activity can slow the decline in performance, even if it cannot completely stop it.

« Now we will look for the mechanisms behind why everyone reaches their peak performance at age 35 and why physical activity can slow performance loss but not completely halt it. »

Published in the Journal of Cachexia, Sarcopenia and Muscle, the research aims to offer a unique long-term perspective on how physical capability evolves across the decades. The investigation also found that holding a university degree was linked positively with both aerobic fitness and muscular stamina.

Initially, the researchers sought to determine whether the musculoskeletal deterioration most people begin noticing in their 60s might actually stem from underlying tissue changes occurring many years prior. Put simply, they wanted to identify the age at which people’s fitness levels begin their downward trajectory.

This phenomenon had already been documented among elite athletes, demonstrating they achieved peak physical condition before turning 35, but the scientists were keen to establish whether this pattern extended to the wider population.

The Swedish research started in the 1970s and tracked 427 randomly chosen participants born in 1958 from the Swedish population. These participants were observed from age 16 through to 63.

The study repeatedly assessed fitness and strength levels among participants over the decades, making it among the most thorough research projects of its kind – and the work continues today.

When participants turn 68 next year, they’ll undergo another round of examinations. Scientists are optimistic these newest findings will shed light on the links between physical performance, lifestyle decisions, general wellbeing, and fundamental biological mechanisms.