No kidding. When my regular walking schedule is interrupted, if just for a day or two, I feel it the next day after a walk. I call it "needing 50 paces to become ambulatory." After that, I'm ok.
I'll be 62 in three months. I need to step it up, as I will celebrate my birthday with a 16 mile walk along my favorite trail (Campion Trail in Irving).
Re you 16 mile walk - good for you. One of my friends gave me a block of wood for Christmas complete with instructions: Place on floor and walk around all four sides. Then you can say you walked around the block.
At age 76 it suits me fine and was the perfect gift. Orthopod keeps talking about knee replacements which I refuse. Going out with what God sent me in with.