There is a saying that running on an empty stomach in the morning can burn more fat. The reason is that after a night of sleep, the glycogen in the body has been depleted, and when running in the morning, the body can only directly consume fat to provide calories. This reason sounds quite reasonable, but is it really like this?

　　Generally speaking, the blood of an ordinary person contains about 5 grams of sugar, the liver contains about 100 grams of liver glycogen, and the muscles contain about 400 grams of muscle glycogen. The sugar content in the human body is mainly composed of these three parts, all of which can provide heat for the body. When the human body is in a resting state, it consumes approximately 1 kcal/kg body weight/hour of calories, and the level of calorie consumption during deep sleep is even lower than this standard. Even when sleeping soundly, the calorie consumption is 1 kcal/kg body weight/hour. For an adult male, if he weighs 60 kg and sleeps for 8 hours at night, the energy consumption is 480 kcal. Assuming that all 480 calories are powered by sugar, and 1 gram of sugar can provide 4 calories, then sleeping at night can consume up to 120 grams of sugar, which is still far from exhausted.

　　Have the runners seen it clearly? After a night of sleep, the maximum consumption of sugar in the body is less than 1/4. This is still an ideal value calculated based on the assumption that the body relies solely on glycolysis for energy during sleep. In fact, nearly half of these 480 calories during sleep are provided by fat breakdown, which means that one night's sleep actually consumes about 60 grams of sugar. So there is no scientific basis for the statement that 'running in the morning completely relies on consuming fat to provide calories'. Morning running is still powered by a mixture of sugar and fat, and there is currently insufficient scientific evidence to prove that morning running is more beneficial for burning fat.

　　Although running on an empty stomach in the morning may not reduce fat more than running at other times, it still has many benefits, such as helping to develop the good habit of going to bed and getting up early, and helping to develop the good habit of eating breakfast every day.

　　(From Dahe Health News)