Just Do It: 5 Moves to Strengthen Your Back
Targets: Deep abdominal and lower back muscles, pelvic floor
A. Begin on all fours, hands under shoulders, knees under hips, neck and lower back straight.
B. Slowly pull lower abs up toward spine. Hold 20 seconds, breathing easily, then let go, 3 times.
You're doing it wrong if... neck and lower back sag.