At what age do individuals typically begin losing significant muscle mass if inactive?

Individuals typically begin losing significant muscle mass around the age of 30 if they are inactive. This phenomenon, known as sarcopenia, is a natural part of aging that can be exacerbated by sedentary lifestyles. Starting in early adulthood, muscle mass begins to decline gradually at a rate of about 3-8% per decade. Consequently, by the time individuals reach 30, they may notice changes in muscle strength and size, particularly if they do not engage in regular physical activity or resistance training.

Understanding this age threshold is crucial for emphasizing the importance of physical activity and strength training throughout adulthood to mitigate muscle loss and maintain physical function as one ages.