A 47-year study reveals the age when your body starts losing strength
A 47-year longitudinal study from Sweden indicates that physical fitness and muscle strength typically begin to decline around age 35. However, the research emphasizes that consistent physical activity throughout adulthood can still significantly improve health outcomes.
Why it matters
Understanding the timeline of physical decline helps individuals make informed decisions about long-term health and exercise habits.
Aging may begin to affect your physical abilities earlier than you expect. A remarkable 47-year Swedish study found that fitness, muscle endurance, and physical performance generally begin declining around age 35, even among people who remain active.
But the findings also offer an encouraging message. Although exercise cannot completely prevent the physical changes associated with aging, becoming more active during adulthood can still produce meaningful improvements in fitness and strength.
Researchers at Karolinska Institutet in Sweden spent nearly five decades tracking how people's physical abilities changed as they grew older. Their findings, published in 2025 in the Journal of Cachexia, Sarcopenia and Muscle , help explain when physical decline begins, how it progresses, and why staying active remains important throughout life.
A 47-Year Study Reveals When Physical Fitness Peaks
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