It can only take more than 20 minutes (at this time, the fat begins to decompose, and these 20 minutes consume the calories of food in a day). The best time is 40 minutes to an hour, or even an hour and a half. The best exercise is not running, but jogging. Your feet must be raised alternately to maintain a certain strength, and you can't stop while running. . . . . . In addition, we should do anaerobic exercise of arms and legs, which will keep the metabolic rate at a high level for about 24 hours, while the previous aerobic exercise can only last about 1 hour. Diet also needs attention. If in doubt, please answer in detail in the next step.