The correct operation is as follows:

Action one

1, two people sitting back to back, waist straight. Legs are shoulder-width apart, feet are hooked, and hands are hanging at your sides.

2. Keep your hips and back bones close together, bend your upper body forward slowly until it reaches its limit position, stop and keep breathing for 3-5 times.

Action 2

1, two people sit face to face, knees bent, one person's legs included, one person is outside, toes hook each other's calves, hips are fixed, hands hold their chests, elbows touch knees.

2. Hook each other's calves with their feet as the support point, and both of them can't lean back and do sit-ups at the same time. Repeat 15 to 30 times.

Action 3

1, back to back, elbows buckle elbows, one person bends forward, and the other person relaxes and leans back. Alternately.

Action four

1, a Lie on your back on the fitness ball, with your back close to the fitness ball, your abdomen tightened and your legs straight.

2. lunge your legs forward and backward. Keep your hands straight and hold A's hand.

Action five

Boys bend their elbows, and their chests cling to the ground but don't touch it. Do push-ups, and the girl's hips will sit back. Bend your knees so that your thighs are as parallel as possible to the ground and do squats. Two people get up at the same time and return to action 1. This set of movements can be done 10 to 20 times, depending on the physical strength of the pair. Boys can exercise their arms, chest and core, while girls can exercise their arms, hips, thighs and core.