Oh, definately physical fitness is a factor. I'm phyisically fit for a 60 yr. old, but not able to compete with a 20 yr. old ... no matter how much my mind thinks I can.On my younger days I could work all day outside in this weather, no problems.
Nowadays not so much. I definitely think it's because of physical fitness comparing now, and then.
I can still work all day in this but much slower.
In my younger days, I was a roofer ... GREAT tan ... drank gallons of water and only peed once a day ... thick and as yellow as a lemon rind.
Now, I'm drinking 6-8 liters of water a day and feeling sooooo much better. Still can't compete with a 20 yr. old, but beginning to understand the question ... Who f***ing cares?