Last year, I lost to the finalist of NorCal's 65's. He was 67 years old, fit as a 40 year old. He did not play sports until he was 50. Saved his body.
Now look at ex pro tennis and football players. Their bodies are shot. I'm no ex pro football player, but did play 2 years of varsity and one JV, while in Spring, played varsity basketball for 3 years.
At 63, my body is shot, the wheels coming off very quickly.
I know theres a vid of a 63 year old who beat a Div1 player in a tourney. Problem is, he almost died after that, and never to be repeated ever again. Said Div1 player probably should not have gotten drunk the night before, and might take his "cakewalk" matches more seriously.