CRISSCROSS Works abs, obliques, quads
On back, clasp hands behind head and slightly lift the tops of your shoulder blades off floor. Straighten and lift left leg a foot off the floor as you twist at waist, bringing right knee slowly in toward left shoulder (as shown). Be careful not to round your back or pull on your head or neck. Hold for two counts, then twist to the other side for one rep. Aim for 8 to 12 reps.