“Try and get a rise from an atrophied muscle,
And the nerves in your thigh just quivers and fizzles
So you know, that you're over the hill
When your mind makes a promise that your body can't fill“
Lyrics by Paul Barrere, & Gabriel Paul Barrere
Let me know if it strikes a chord with you. It’s from the last verse of "Old Folks Boogie" by Little Feat. Here's a live version from YouTube:
The track's from the 1977 album "Time Loves A Hero" but it's also available on the 1994 "best of" album "As Time Goes By". I've had a copy of the latter since it came out. It's a truly wonderful album chock full of great tunes and much much better than "Time Loves A Hero". Recommended.