People who look a little fat on the surface are mostly caused by too much fat (more fat and less lean meat). When you do corresponding exercise, fat (fat meat) will be transformed into muscle (lean meat). Therefore, whether doing aerobic exercise, doing sit-ups, jogging, walking fast or swimming, it takes more than 30 minutes (at least 40-80 minutes) to start losing weight. Because the body itself has a period of self-adjustment, the whole metabolic system should adapt to the "new" state, gradually transform fat into muscle, and narrow the gap between subcutaneous fat. There will be no big change in weight during this period. Only when the muscles reach a certain density, the burning fat will be converted into energy and consumed, and then the weight will be gradually reduced. It takes 1-3 months to take effect, and slowly it takes 3-6 months to take effect.