The legs of the world's fastest man (Usain Bolt) can develop up to 5 times the force compared to those of normal people. What stops him from being faster? A normal healthy high-school student can complete the 100 metres in 11-13 seconds while Usain Bolt takes 9.58 seconds. If Usain Bolt's legs can exert so much more force than a high-school student, then how is it that the student can complete the race in 11-13 seconds?
F = ma = 94 x 12.517 = 1183N (correct me if I'm wrong)
So Usain Bolt's legs can exert 1183N on the ground.