I've turned 50 and continue to do my fitness test (and pass it), even though I am in the 'back of beyond'. A WO recently visited my location - bulging over his belt of his CS95, sweating and generally looking like a sack of sh!t. I suspect he would never pass a fitness test and was, frankly, a disgrace in uniform. I'm sure he is a good technician but I would not want him on my team on ops. The fitness test, unfortunately, hasn't winnowed characters like that out, but I wished it had!
Cue incomiong assaults about whippets dropping like flies on ops....etc etc....