Lie face-up on the floor with your legs extended toward the ceiling and palms flat on the floor on either side of your hips. Your whole back should be pressing into the mat.
With control, lift your hips a few inches off the mat. Think about lifting straight up to the ceiling, and avoid bringing your thighs closer to your face. Lower your body back down with control.
Repeat for 10 to 30 seconds, then rest for a maximum of 30 seconds.