Many people have been asking whether it is better to exercise in the morning or in the afternoon, or how to lose fat quickly, so experts recommend "doing aerobic exercise on an empty stomach". The order of energy metabolism during exercise is carbohydrate, protein and fat. Long-term exercise will eventually consume fat, and the metabolism in the body will go on as usual during sleep, so the carbohydrates in the body will be exhausted after getting up in the morning. Exercise under hypoglycemia will of course consume fat faster and the effect will be more obvious.