- Lie down on the floor with both hands underneath your lower back, supporting the lumbar spine — this will help prevent the lower spine from flattening against the floor and minimize stress on your back.
- Keep one leg extended and bend the other leg, bringing the foot in line with the opposite knee.
- Brace your core to prevent movement (no pain should be felt here), and lift the elbows off the ground.
- Maintaining a neutral neck and spine, slightly lift your head and shoulders off the floor.
- Hold for 10 seconds, and then lower back to the starting position.
- Set one: five reps with an eight- to 10-second hold. Rest for 30 seconds.
- Set two: three reps with an eight- to 10-second hold. Rest for 30 seconds.
- Set three: one rep with an eight- to 10-second hold. Rest for 30 seconds.
McGill notes that this move is not the same as a crunch and that those with back pain should avoid crunches. After day one, see how you feel and add one repetition to each set. If there is leg/butt pain, bend the knee on the side with pain.
(You can see this exercise performed in the video right around the 1:30 mark.)