The stuff about JD was fun. But seriously being more fit does not necessarily contribute to more speed...almost all tour pros are at a high level of fitness these days. Brian gay looks very fit. Daly is more fit now than he ever was, except for when he first appeared...he's always hit it long.
Equipment...all tour pros have access to the same technology. Some that are older, have more speed than some younger. I have more speed than most of them now - but hold on - I know I don't have their consistency
so don't go there! I bet if I tried their fitness routine it would be a 911 call before i got 1/2 way through.
The idea behind the OP was to show one OBVIOUS difference between short knockers and long knockers. They are the same, irrespective of age, fitness level, or equipment. Watch video of 60 year old Mike Autin.
Your golf game can benefit form fitness...but you don't need to be fit to generate speed.
Never quit til you have a swing you'll never forget!