"My legs used to quit on me"
I'm 63. I'd get a block from the house and my calves would tighten up so bad I had to stop and pretend I was looking at something. Told myself it was just my age.
About six weeks in, I made it all the way around the block without stopping. Didn't even notice until I was back at the door.
Now I walk the dog the long way on purpose. My wife says she has to keep up with me for a change.