Thin people's abdominal muscles are easy to practice because there is no excess fat in the abdomen to cover the abdominal muscles.

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 four times a week, and practice three groups with one movement at a time, each group doing about 15.