Spinning is an aerobic exercise, like jogging and swimming, which is mainly to lose weight. If the purpose is to practice abdominal muscles, you can't practice developed massive abdominal muscles only by rotation, because rotation can only reduce abdominal fat and can't practice abdominal muscles. It is good for women who practice vest line (Sichuan abdominal muscles).

If you want to exercise your abdominal muscles, you can usually do more supine leg lifts. Do 4 groups, each group is about 10, and each group has a rest 1 minute.