It is not good to exercise on an empty stomach because exercise requires a lot of energy and consumes glucose in the blood, which can easily lead to hypoglycemia, dizziness, nausea, sweating, palpitations and other symptoms. Severe cases can lead to shock, and even fall injuries. Half an hour before exercise is best to eat something, such as a glass of milk or honey water, can provide energy for exercise and improve the quality of exercise. It is not advisable to exercise immediately after a meal. If it is a light exercise, such as walking, it should be done half an hour after the meal. If it is a medium-intensity exercise, such as jogging, playing table tennis, etc., should be carried out an hour after the meal. If it is a high-intensity exercise, such as weighted squats, sprint running, etc., should be carried out two hours after meals.