No one can accelerate for a full 100 meters. Speed must be...

No one can accelerate for a full 100 meters.
Speed must be distributed strategically.
The mechanics of the a 100 meter sprint require a low, explosive start from the blocks.
Sprinters must avoid popping up too quickly and losing momentum or braking by striking the ground too far in front of their bodies.

Then comes the acceleration phase.
Speed is a function of the length and frequency of strides. Top speed is reached at about 60, 70 or 80 meters.
The challenge becomes trying to hold as much speed as possible while decelerating to the finish line.

The outcome of a 100-meter race is essentially an optical illusion. The winner is not speeding up the fastest but slowing down the slowest.

“You can only for five or six seconds produce maximum contraction” of the muscles, said Olivier Girard, an exercise physiologist who studies sprinting at the University of Western Australia.