The starting position of sit-ups is lying on a flat cushion or on a sloping board with your head up. Hold the fixed object at the back of the head with both hands, contract the abdominal muscles when the whole body is straightened, and bend the leg that remains straight upward as much as possible. Hold it for a second, and then let your legs fall back slowly. Breathing method Inhale when your legs are bent upward, and exhale when you fall backward. Pay attention to the main points. When you fall off your leg, you should still control your abdominal muscles to avoid falling too fast. After doing sit-ups, you can also do twisting exercises after resting and relaxing. Twist from left to right first, then from right to left. Ten moves in a group, slow down as much as possible, and finish in five seconds. This can not only relax the tension of the whole body, but also exercise the muscles of the waist and abdomen well and achieve good results.

2, dumbbell wrist

Main target muscle: flexor digitorum forearm. Action essentials: Sit with your forearm on a Swiss ball, hold a dumbbell and flex your wrist to contract, and exercise your forearm flexors. Weight loss group: light weight 10 times per group, ***6 groups, muscle gain group: medium weight 8 times per group, ***4 groups.

3, roll the abdomen

Main target muscle: rectus abdominis. Cooperative muscles: external oblique muscle and quadriceps femoris. Action essentials: lie on your back, with your hands empty, put your head on your sides and your calves on the Swiss ball. The rectus abdominis exerts force, so that your upper body slowly leaves the ground, avoiding inertial force and keeping it under control. Weight loss group: 30 times in each group, ***5 groups, muscle gain group: 40 times in each group, ***5 groups, strength group: chest load, 20 times in each group, ***4 groups.

4. Sit down and lift your legs.

This action can better stimulate the lower part of abdominal muscles. Sit on the edge of the bench, stretch your legs forward and down, lean back about 10 degrees, grasp the edge of the bench and keep your body balanced. Don't bend your knees, lift your legs. Until the toes are parallel to the eyes, the control force, control force and tension are very important in the whole movement, and a slight negligence may lead to lower back injury. As the abdominal muscles become more and more tired, you can gradually bend your knees until you are completely exhausted. Many people like to lie flat on the bench to do this action, which will cause the hips and abdomen to twist the arc tension of the abdomen and concentrate more tension on the hips rather than the lower part of the abdominal muscles. Main target muscles: the middle of rectus abdominis and the oblique muscle outside abdomen. Action essentials: lie on your back on the Swiss ball, support your head with both hands, and put the opposite leg on your knee with one leg. When the rectus abdominis slowly contracts and descends, it can be stretched properly and the whole process can be controlled. Body group: 30 times in each group, ***8 groups, muscle training group: 40 times in each group, ***5 groups.