The key to practicing abdominal muscles is the intensity of movements, not the more times, the better. For example, doing 200 sit-ups at a time is not as good as doing 10 at both ends. Because being able to do more than 200 exercises is endurance, the thickening of muscle fibers is not obvious.
Four actions to exercise abdominal muscles: sit-ups, supine leg lifts, double-headed leg lifts and suspended leg lifts (the intensity increases in turn). If you can do more than 30 sit-ups, then do sit-ups and leg lifts; If you can do more than 15 supine leg lifts, do it from both ends; If you can do more than 15 from both ends, you can do leg hanging. Practice three times a week, one action in three groups at a time, and each group does about 10. In addition, fat with a body fat rate higher than 10% will cover abdominal muscles. This is why sumo has no muscles. If you have a small belly, you need to jog for about 40 minutes to lose fat. About 3 to 5 times a week. If you can't run for 40 minutes at a time, you can walk for a while.