Works: low and mid-back, butt
A. Lie face down with your arms extended above your head and your legs straight, shoelaces facing the floor.
B. At the same time, raise your feet, arms and shoulders off the floor, contracting the muscles in your low back. Avoid jerky movements or looking up as you lift your arms and legs; keep your neck aligned with the rest of your spine.
C. Hold for two seconds and return to starting position. Do 12 to 15 repetitions.