Decline starts at 35: a 47-year Swedish study shows late-life workouts still boost performance
A 47-year longitudinal study from Karolinska Institutet tracked hundreds of Swedes aged 16–63, finding fitness, strength, and endurance begin to decline around age 35 and continue gradually with age, but starting or maintaining exercise in adulthood can improve physical capacity by about 5–10%, underscoring that it’s never too late to move.