Position yourself correctly and know your sport
The best thing you can do is to position yourself with the sun behind your back. This ensures that a lot of light is hitting your subject out on the field of play, which reverts back to letting as much light in as possible and freezing the action with those fast shutter speeds. It is also helpful if you know a lot about the sport you are taking photos of as anticipating where the ball or the action may be is going to help you get the best shots possible. Follow the action with your camera, ensuring that you are zoomed in close enough to have the majority of the frame be the player themselves.