system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do athletes spit out their drinks instead of swallowing it?
gpt
Water, especially cold water, can cause painful stomach cramps during intense exercise. 

Rinsing the mouth gets rid of the dryness, and hydrates a little. 

In most cases, the athlete knows that drinking water will be available after their cool down, and rinse their mouths so they don't get cotton mouth or breathing problems.