- Lie on your back.
- Place your hands, palms down, on the floor beside you.
- Raise your legs off the ground (Exhale as you go).
- Keep your knees locked throughout the exercise.
- Hold for 30 seconds, or as long as you can (with some routines, there is only a short contraction/holding period).
- Return to starting position (Inhale as you go).
- Repeat the movement for the prescribed number of repetitions.
See the video here.