2012
Frontiers in Physiology
Sarcopenia, Dynapenia, and the Impact of Advancing Age on Human Skeletal Muscle Size and Strength: A Quantitative Review
Studied: Review of cross-sectional and longitudinal aging studies
A foundational review distinguishing 'sarcopenia' (losing muscle size) from 'dynapenia' (losing strength). Strength is lost two to five times faster than muscle size — meaning strength itself needs direct training, not just muscle mass.