Many events in track use force, including sprinting events (starting blocks) and pole vaulting.
Sprinters use blocks to get the greatest force possible so that they can get a good start to their race. Blocks help achieve low shin angles, a 120-135° angle on the rear leg, and a 90-110° angle on the front leg which requires to allow a stretch reflex in the hamstrings. The front leg requires a higher block angle and leg angle because that leg will provide the force needed for propulsion. Newton's third law states that for every action there is an equal and opposite force created; therefore, when a sprinter pushes against the blocks, the blocks push back with the same force. The force the blocks push with helps the sprinter to move forward.
Force x is the force that gives the runner power to move forward quickly, and force g acts through the center of mass of the runner, as represented by the purple dot.
Sprinting around a turn, such as the 200 m and 400 m races, is proved to result in a longer race time than if the race were run on a straight track. This is due to the centrifugal force experienced by the runner as he goes around the curve of the track. This has the effect of decreasing the force available for the runner to propel himself around the track. This effect is more clear the smaller the turn radius is.
The figure below shows the contact forces acting between the runner's foot and the curved track.
Sprinting around a turn, such as the 200 m and 400 m races, is proved to result in a longer race time than if the race were run on a straight track. This is due to the centrifugal force experienced by the runner as he goes around the curve of the track. This has the effect of decreasing the force available for the runner to propel himself around the track. This effect is more clear the smaller the turn radius is.
The figure below shows the contact forces acting between the runner's foot and the curved track.