tall skinny Masters runner said: Why are most good Masters runners short? I'm always getting beat by these 5'8" tanks.
I'm 60, and I'm speculating a hypothesis, because I have also noticed the same thing and have wondered about this.
1. as discussed above, age affects the type of training that you do. many Masters run a lot less and use the gym a lot more than runners half their age. I remember one guy who broke the world indoor mile record in his age group last year said he ran only every third day. but he was a very finely muscled guy and looked more like a discus thrower than a runner because he does a LOT of weights and circuit training. other good Masters athletes train in a similar way.
2. this sort of training is easier to do in sufficient quantity to be competitive if you adhere to a basic height/weight ratio. I'm not claiming to know what the number is but if you are too tall your limbs tend to be longer and you have to move the weights through a greater range on longer levers. if you are too short you are not moving the weights far enough to maximise the benefits but at a certain height and lever length you get maximum benefit for the effort required.
3. therefore, the guys who are the right size and do the right training will succeed. taller guys, like me and you, have to suck it up and hope the other guys die off first.
cheers.