Eat breakfast after exercise, or eat breakfast and then exercise each has its own advantages and disadvantages, should be based on personal health conditions to choose the appropriate mode of exercise. During exercise will consume a lot of energy, the body’s energy is mostly provided by the body fat, sugar and other substances. Exercising on an empty stomach may cause too little sugar in the body, leading to hypoglycemia, palpitations, sweating, dizziness, nausea, coma and so on. It is recommended to add some sugar in moderation before exercise to avoid hypoglycemia during exercise. However, exercising after eating breakfast may result in cramps, dizziness, and regurgitation during exercise because of strenuous exercise after overeating. It is recommended to do light exercise 30 minutes or 1 hour after meals to avoid aggravating the burden on the gastrointestinal tract. For moderate to high intensity exercise, two hours after breakfast is required.