New research confirms what many athletes suspect: peak physical performance arrives earlier than we think. A long-term study from Sweden’s Karolinska Institutet, following 427 people over nearly 50 years, found that physical ability begins to decline around age 35. However, the rate of decline is significantly slower in those who remain physically active.
The Study’s Findings
Researchers measured vertical jump ability (a key indicator of muscle strength) and aerobic capacity to track physical performance across the lifespan. The study revealed a gradual decline starting at age 35, with a drop from 30% to 48% by age 63. But this doesn’t mean inevitable collapse: participants who exercised consistently experienced a much slower deterioration.
What Does “Decline” Mean?
The rate of decline isn’t catastrophic. According to Maria Westerståhl, PhD, lead author of the study, the initial drop is only about 0.5% per year. This accelerates after age 60 to over 2% annually. This means a subtle weakening over time — not an immediate crash in ability.
“The stronger you are before the decline sets in and the more you exercise afterward, the later—if ever—this restriction to your independent life will occur,” Westerståhl explains.
Why Performance Drops After 35
Several factors contribute to this slowdown. Muscle loss is a primary driver, especially if activity levels decrease. As Brad Wilkins, PhD, explains, unused muscles waste away, reducing strength and endurance. Shane Davis, MD, adds that the natural aging process also impairs nerve-muscle signaling, slowing reaction times and overall performance.
How to Prolong Peak Performance
The good news: decline isn’t fixed. Consistent training can significantly slow the process. “The height of your fitness peak and how fast you come up and go down does seem to be changeable,” Wilkins says.
Key strategies include:
- Adapt Your Training: As you age, optimize your workouts for your body’s changing needs.
- Nutrition and Sleep: Improve your diet and sleep habits to support recovery and performance.
- Stay Active: Even later in life, physical activity can help you perform at a level comparable to someone five years younger.
The Bottom Line
Physical decline is inevitable, but not irreversible. Consistent exercise, smart training, and healthy lifestyle choices can delay the drop-off and maintain functional fitness for decades. Don’t assume your peak is behind you—you can still push your limits and stay strong as you age.
