Eat before or after exercise to be determined according to the time period of exercise, if it is the morning exercise is generally first exercise after dinner, but to prevent the production of hypoglycemia, because the body’s energy consumption at night has been almost, if the exercise is too strong is likely to appear hypoglycemia. If it is evening exercise is generally functional exercise after meals, but must ensure that an hour after meals, otherwise it may lead to poor digestive function stomach discomfort. If it is during the day time period before and after meals can be, a general principle is to ensure that an hour before meals do not exercise, an hour after meals do not exercise is the best time to exercise.