SEATED STRAIGHT-LEG RAISE. Sit with legs extended straight on the ground, spine tall and abdominals contracted. Bend your right knee, bringing your right heel toward your groin. Wrap your arms around your right knee, then contract the top of your left thigh and lift your left leg 2 to 4 inches off the ground. Hold for 5 seconds, then slowly lower leg to start position and repeat for reps. Switch sides and repeat.