Many athletes make the mistake of loading up on sugar before intense exercise. They eat candy, drink something ultra sweet, or drink a sports drink. These are the worst things they can do. Sugar elevates insulin in the bloodstream.
Exercise makes insulin dump glucose into the muscles for fuel.
The body responds by stopping its production of glucose in the liver. As a result, the athlete's performance will suffer. The body is forced into premature exhaustion. Dizziness, nausea, and headache occur. To avoid this, do not drink or eat something sugary within two hours before heavy exercise.