Some years ago I was at RAF Headley Court, the excellent medical rehab unit for the RAF and Army. While doing my impression of a jellyfish in the 'early spines' group the energetic young army PTI announced that their aim was to get personnel back to the fitness level required by their job.
In my case, being aircrew, I was expected to be able to climb on to the bar stool in the 'Boozeotherapy' department wheras the unfortunate army captain next to me was going to be beasted to death! Obviously I pointed out to the rather depressed looking Pongo that he should have tried harder at school.
The doctors surgeries are full of jockstappers who punish their bodies to the point of failure. Everybody knows that you're only born with so many hearbeats in the bank so why waste them in the company of sweaty blokes with dubious taste in shorts when you could use them up walking to the pub!