Study Reveals Aging's Impact on Physical Performance Starting at Age 35, But Highlights Benefits of Late-Life Exercise

A comprehensive Swedish study spanning nearly five decades has revealed important insights into the aging process and its impact on physical performance. Conducted at Karolinska Institutet, the research, a part of the Swedish Physical Activity and Fitness study (SPAF), tracked hundreds of randomly selected men and women, ranging in age from 16 to 63, through repeated fitness assessments over 47 years. Published in the Journal of Cachexia, Sarcopenia and Muscle, the study is notable for its long-term approach, diverging from previous research that typically employed cross-sectional comparisons of different age groups. This longitudinal method allowed scientists to gain a more detailed understanding of how various physical capabilities evolve throughout adulthood and into older age. The findings indicate that physical performance, including fitness, strength, and muscle endurance, begins to decline around the age of 35. This decline occurs gradually and tends to become more pronounced with advancing age, impacting individuals regardless of their previous training backgrounds. The research specifically highlights that the decreases in fitness, muscular strength, and endurance closely follow a similar downward trajectory. Despite these findings, the study presents a hopeful perspective: engaging in physical activity later in life can lead to significant improvements in physical capacity. Participants who adopted an active lifestyle during adulthood demonstrated gains in their physical abilities ranging from 5 to 10 percent. “It’s never too late to start moving,” said Maria Westerståhl, a lecturer at the Department of Laboratory Medicine and lead author of the study. She emphasized that while exercise cannot completely prevent the downward trajectory of performance, it can effectively slow it. Researchers are now aiming to investigate the underlying mechanisms that explain why individuals typically reach peak performance by the age of 35 and why physical activity can mitigate, but not entirely stop, performance decline. To further this exploration, the researchers plan to continue tracking these participants as they advance in age. Next year, when many participants turn 68, another round of testing is scheduled. The ongoing research aims to uncover how lifestyle choices, overall health, and biological processes collectively influence changes in physical performance throughout a person’s lifetime.