When the oxygen supply is sufficient, the exercise consumes basically glycogen and fat; when the oxygen supply is insufficient, the consumption is basically glycogen. Morning fasting fat burning exercise is recommended to carry out aerobic exercise recommended at about 7:00, exercise for more than 45 minutes, of course the moment of exercise is not necessarily, can be changed according to the situation. The greater the intensity of the exercise, the greater the oxygen demand, the better the effect of fat burning, but note that the body also needs to be able to bear the premise. 1, the length of exercise: more than 45 minutes of continuous aerobic exercise can burn fat. The first 15 minutes of aerobic exercise, mainly by liver glycogen, muscle glycogen energy supply, 15-20 minutes after the fat began to supply energy, the exercise time is too short to achieve the purpose of fat burning. If the physical fitness is not very good or no previous exercise habits, you can be divided into multiple exercises, one exercise 10 minutes, a total of 45 minutes; 2, the moment of exercise: generally speaking, about 7:00 in the morning is more suitable for aerobic exercise, such as morning running, rope skipping, etc.. But due to seasonal changes, the specific moment of exercise is not fixed, it is recommended to exercise in the morning after the sun rises. And after a full night’s rest, the body is in a more relaxed state, the secretion of testosterone is relatively strong, the morning outdoor air is fresh and the oxygen content is high, these are favorable factors for physical exercise. However, when the weather is bad or the air quality is bad, it is not recommended to go out for a morning run, you can choose indoor aerobic exercise. People’s physical strength changes periodically and individual differences, should try to choose their own physical strength to exercise at a better time, can achieve better fat burning effect. It should be noted that it is not recommended to exercise on an empty stomach for people with low blood sugar and weak constitution, and you can choose to exercise after eating some low-calorie rough food or one hour after a meal. In addition, the morning after exercise should not eat immediately, you can rest for a period of time before eating, so as not to cause indigestion.