Since athlete is undergoing Circular Motion so there is a change in direction but Not velocity and he will have certain non zero acceleration due to change in direction.

In circular Motion There are two types of Acceleration, Tangential and Normal but there is no change in the magnitude of velocity so he will experience only Normal acceleration.

Given 36kmph which is same as 10mps

Acceleration=v^2/r

                 =100/25

                 =4mpss