Modeling human running on a soccer field

Question

In a soccer game, I am computing a steering force using steering behaviors. This part is ok. However, I am looking for the best way to implement simple 2d human locomotion.

For instance, the players should not "steer" (or simply add acceleration computed from steering force) to its current velocity when the cos(angle) between the steering force and the current velocity or heading vectors is lower than 0.5 because it looks as if the player is a vehicule. A human, when there is an important change of direction, slows down and when it has slowed enough, it starts accelerating in the new direction.

Does anyone have any advice, ideas on how to achieve this behavior? Thanks in advance.