# Karolinska Institutet study on physical aging > Live situation record from CLSTR: https://clstr.news/situations/karolinska-institutet-study-on-physical-aging > Updated: 2026-10-24T05:30:10.000Z. Sources: 8. Developments: 2. A 47-year longitudinal study conducted by researchers at the Karolinska Institutet in Sweden has identified that physical strength, muscle endurance, and aerobic capacity typically begin to decline around age 35. The research, part of the Swedish Physical Activity and Fitness (SPAF) study, tracked 427 participants born in 1958 from age 16 to 63. Findings published in the Journal of Cachexia, Sarcopenia and Muscle indicate that while these metrics peak between the ages of 26 and 36, they decline by 0.3 to 0.6 percent annually after that period, with the rate of loss eventually accelerating to as much as 2.5 percent per year. By age 63, measured parameters such as muscular strength and aerobic capacity had decreased by approximately 30% to 48% compared to peak levels. Lead author Maria Westerståhl noted that while regular physical activity can significantly slow the decline, it cannot stop it entirely. However, the study emphasizes that individuals can still improve their strength and fitness through training even after the age of 35. ## Timeline ### 2026-10-24: Swedish study reveals physical decline begins around age 35 A 47-year Swedish study shows that physical strength and aerobic capacity begin to decline around age 35, though regular exercise can slow this process. 2 sources. https://clstr.news/cluster/swedish-study-reveals-physical-decline-begins-around-age-35 ### 2026-10-19: Karolinska Institutet study finds physical decline begins around age 35 A 47-year study from the Karolinska Institutet shows that physical strength and aerobic capacity peak between ages 26-36 and begin to decline around age 35. 5 sources. https://clstr.news/cluster/karolinska-institutet-study-finds-physical-decline-begins-around-age-35 --- Cite as: Karolinska Institutet study on physical aging. CLSTR, https://clstr.news/situations/karolinska-institutet-study-on-physical-aging