Eat a snack or a small amount of food one and a half to two hours before you start running. And you should choose carbohydrates and foods that are low in fat, fiber and protein. For example,

A bagel with peanut butter, a banana and an "energy bar";

A bowl of cold cereal and a glass of milk.

There are usually three categories that should be eaten before running:

First, ground foods, such as pasta, white rice and steamed buns, are all good choices. Although they are not as nutritious as whole grains, they are easier to be digested by the stomach because they have been made;

Second, low-fiber fruits and vegetarianism, if you must eat fruits before running, you have no choice. Pumpkins, tomatoes, olives, grapes and grapefruit are all low in fiber content;

Third, safe milk, some people can't digest it after drinking it before running. However, soybeans, rice and milk containing almonds usually don't have too much indigestible lactose.

Three major food categories should be avoided:

The first is high-fiber food, including all whole grains, vegetables, beans and high-fiber fruits, which may cause gastrointestinal diseases and diarrhea;

The second is high-fat food, such as fried food, cheese, hamburger or barbecue, which is difficult to digest and will upset the stomach during running;

Thirdly, caffeine, like coffee and caffeinated drinks, can also cause gastrointestinal problems and diarrhea. However, if you are a long-term coffee drinker, you may still have no problem running after drinking coffee.