This article by Lon Kilgore, PhD, explores the relationship between aging, strength loss, and physical activity. Lon begins by addressing the common belief that organ systems lose about 0.68% of their functional capacity per year after age 30, a decline that accumulates over time and contributes to frailty. However, data shows that strength loss in sedentary individuals occurs at a much faster rate than organ system decay alone can explain, suggesting that inactivity accelerates the decline in physical function.

Data from masters athletes in weightlifting and powerlifting demonstrates that those who continue structured training maintain far greater strength than sedentary or casually active individuals. Strength decay among competitive lifters still exists, but it is slower than in sedentary populations, pushing the onset of frailty back by decades. The analysis also highlights how reductions in training volume and intensity, especially after age 50, appear to be a major factor in accelerated strength decline among older lifters rather than biological limits alone.

Consistent exercise, particularly weight training, can combat the age-related loss of strength and function. Kilgore points out that sports participation and gym membership are low among older adults, and even among those with memberships, most do not train frequently or intensely enough to maintain fitness. He argues that increasing physical activity—doing “more than you’re currently doing”—can delay frailty and dependence, with weight training being one of the most effective ways to preserve health and independence as we age.

https://brokenscience.org/longevity-and-strength-why-do-the-old-get-weak/