Lie flat on the ground. Put your arms at your sides, close to the ground, palms up. Bend your knees and lift your hips 90 degrees, and put your calves on the fitness ball. Swing your leg to the left and keep your calf and leg socket in contact with the ball all the time. Restore the position of the leg, use only the strength of the abdominal muscles to complete the action, and try to avoid the exertion of the buttocks. Then, repeat this action to the right. Keep your head, back and arms close to the ground during exercise.

2. Resistance belt rotation

Choose a fitness belt with less elasticity and fix it on the wall and tree. Adjust the distance between you and the fitness equipment so that the fitness belt is just tight. Keep your legs and hips vertical to the ground. Draw an arc with your hands in front of you and rotate your upper body 90 degrees to the left. After returning to the initial position, rotate it 90 degrees to the right. Pay attention to abdominal muscle control. Keep the hip position unchanged during exercise.

3. lunge forward and turn leg press.

Feet shoulder-width apart. Take a big step forward with your right foot and leave your left heel off the ground. Keep your upper body upright. Hold the fitness ball with both hands and stretch forward. The left knee is not more than 10 cm from the ground, the right knee does not cross the right toe, and the center of gravity falls between the feet. When the trunk sinks, the upper body rotates 45 degrees to the left, then rotates to the right, and repeats the action just now. Use the strength of abdominal muscles to keep your hips vertical during exercise.