Question

why do athlete wear shoes that have spikes on their base

Answer 1

The studs can dig into the ground and offer a much larger frictional force than the simple shoes while on grass. In short you can also say, Stud shoes increases friction and enables the player fast running quality. These shoes give a grip on the ground , improving the running speed of the players.

Answer 2

The main motive of spikes on the base of the shoes is to get the proper grip on the ground.

Spikes make the surface of the shoes rough. And if the base is rough, the athlete will be able to catch the grip of the ground much faster and for much longer.

This is because, the rough or spiked surface of the shoes interlocks with the ground.

If the shoes would have been smooth from below, then there would have been high tendency for the athletes to fall or slip or lose grip.

That is why athletes wear spiked shoes for running and playing various sports.