Hello, you can try to lie flat on the bed, with your upper body in the bed, your hips and legs exposed outside the bed, then lift your legs at 90 degrees with your upper body by abdominal strength, and then put your legs down parallel to the ground.

Repeat 10, 10 as a group, and do 20 groups every day. If you feel that the intensity is relatively large, you can gradually strengthen it to ensure the effect.