How to use ps to do that is that athletes are the shadow behind them when they run, that is, they feel that athletes run very fast

First of all, if the characters and background are layered, if it is a picture, the characters should be deducted.

Copy a character layer, put it behind the clear character, apply the filter-blur-motion blur, and adjust the angle of motion blur according to the direction of the character.

You can copy more characters, give them different sizes of dynamic blur and arrange them horizontally, so that you can make a panoramic effect.