Do sit-ups with dumbbells or barbells on the bench and paddle with equipment. If you have 8 abdominal muscles, ① Lie on your back, grab the flat plate with both hands, lift your legs up, get up quickly and release slowly. (2) after the pull-ups, you can grasp the crossbar, and then try to bend your legs and knees. If the strength of abdominal muscles reaches a certain level, you can add weight to your legs before doing it. I hope the answer will help you.