At present, it is considered that the formula for calculating the heart rate to achieve effective weight loss is usually (220- age) x60-75%, and the value obtained according to this formula is the appropriate heart rate times. Therefore, the running heart rate can be calculated according to the above formula, and weight loss has a certain relationship with the type and time of running. Losing weight means losing excess fat instead of muscle. To lose weight by running, we should know the order in which the human body consumes all kinds of energy. Running first consumes sugar, that is, carbohydrates from noodles, rice and so on. And then consume fat. So it takes a certain amount of running time to lose weight. Running for 20-40 minutes a day can achieve the effect of reducing fat, but it should not be too long. Running for too long will damage muscles and make running unsustainable. In addition, running must be aerobic exercise to reduce fat. Aerobic running is rhythmic low-intensity running, such as jogging. Heart rate is often used to measure whether it is aerobic exercise. Aerobic running can not only reduce fat, but also regulate psychological and mental state and enhance physical fitness.