Age-Related Muscle Decline Is Largely Modifiable: It's About Strength and Function, Not the Mass Number

Summary

Sarcopenia is a **real, prevalent, mortality-relevant condition**, and it is **largely modifiable** by the one lever with the strongest evidence and zero industry sponsor — progressive resistance training, which works at any age including the frail oldest-old — so treat it as a **strength-and-function problem rather than a body-composition number**, use adequate real-food protein as a permissive co-factor (it does little without the training stimulus and the premium "2g/kg plus leucine timing" numbers are commercially shaded), correct vitamin D only where deficient, and fix the upstream why (d