Are speed runners usually six and a half feet? If not, why?
What do you mean by a speed runner? And why do you thing 6 1/2 feet is an ideal height?
Because can you imagine a 6’5" or a 6’7" speed runner? 
Jeeze TriPolar, think before you ask a dumb question. 
Up until a few years ago the recieved wisdom was that the ideal sprinter topped out at a little over six feet. Carl Lewis was 6’3" and Michael Johnson 6’1" for example. And a mid 2000s study of world champion sprinters found they ranged between 5’9" and 6’3". The theory was that taller sprinters couldn’t generate the explosive power to win the dashes.
Then along came Usain Bolt at 6’5".
I would think that the taller you are, the longer legs you have and the longer legs you have, the father you run on each step.
Moved to the Game Room.
Colibri
General Questions Moderator
Wilt Chamberlain was a very fast sprinter.