First of all, sit still and tuck in.

1, which takes 2 minutes and takes 24 actions.

Second, the action essentials

1. Hold the edge of the chair firmly with both hands. If you have a handle, you can lean on it. Keep your back straight and lean back.

2. Tighten the waist and abdomen, lift the thighs slightly off the ground, and repeat 3 groups, 8 in each group.