Your muscles are not aging, they are retiring, and the difference is trainable

Studies on master athletes who keep training hard into their sixties and beyond keep finding something awkward for the doom narrative: their muscle cross sections and strength profiles look far closer to younger lifters than to their sedentary age peers.

Muscle loss with age is heavily a story of disuse wearing the costume of time, with a genuine biological slow decline underneath, but the slope of that decline is dramatically flatter in people who keep loading heavy things. The controversial part is what that implies: much of what gets called getting old in a gym is actually decades of accumulated detraining being blamed on birthdays.

Obviously recovery, tendons and joints do change with age and deserve respect, nobody sane programs like a twenty year old at fifty five. But the excuse dies here. People who came back to serious training after years off past thirty five, what surprised you most about what your body still did?