TRUNK CURL AND CRUNCH

Lie on your back with your knees bent and your lower legs suspended so your thighs and shins form a 7, hands crossed over your chest. Brace your abs, then crunch your chest toward your knees while drawing your knees toward your chest at the same time; your shoulder blades and hips both lift slightly off the floor. Touching elbows to knees marks one full rep - squeeze hard there, then lower under control.

Perform the trunk curl and crunch, but between repetitions reach your legs out in front of you rather than keeping them bent, letting the lower abs pull them back in for the elbow-to-knee touch on every rep.