Lie in bed, raise your legs and then put them down, and move slowly; Sit-ups are OK, thin belly.

Kneel on the bed with your hands supported, lift your legs alternately and move slowly, so that you can lift your hips.

Lying in bed, the old lady pedals and can stovepipe.

If you don't like the top, it's better to roll in bed than lie down. Let's go I am also doing sports.