When I was younger, I had several men (young and old) tell me that men liked doing hard physical labor and working out. It was an urge that couldn't be ignored, unless one was a "city slicker." It was a stronger urge than "get fit like normal", it was a desire to get sweaty and intensely physical.
Loading boxcars with 100 lbs sacks of peas or lentils, playing football (pronounced "FOOTBAAAALL!!"), strong manly stuff...I never understood that thought process, but I pass it on to you.