Lie on your back, with your arms at sides and knees bent. Place right foot on a yoga block, and extend left leg along floor.
Raise your left leg up to ceiling, toes pointed. Lift your hips until torso is in one straight line, with your abs engaged. Hold for a second, then lower with control. This completes one rep.
Repeat for 20 reps. For the last rep, hold at top for 20 tiny pulses.
Switch sides, and repeat on your right leg for an additional 20 reps.