Cycling is an aerobic exercise, which, like jogging and swimming, is mainly to lose weight. It has no obvious effect on exercising abdominal muscles.

If the purpose is to practice abdominal muscles, you can't develop a large number of developed abdominal muscles by riding a bicycle, because riding a bicycle without practicing abdominal muscles can only reduce abdominal fat.

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.