A. Lie on your back. Hold the ends of a hand towel under your head to support your neck and head, and lift your legs straight up in the air.

B. Curling torso up, cross the left elbow toward the right knee. As you curl, bring right knee into your body in a crisscross motion to target obliques; alternate legs. Be careful not to pull on your neck.

Boost The Burn: Secure a 2- to 3-pound wraparound weight inside the towel to up the resistance.

A. Lift both legs so knees are in front of your hips, hands behind head. Hold a weight between your knees.

B. Exhale and contract abs to curl shoulders slowly off floor and tilt pelvis slightly forward. Hold the post for 10 counts, then lower and repeat.

Boost The Burn: Make these reverse curls superslow, lifting and lowering for a count of four. At the top of the lift, rotate ribs slightly to each side. Then lower and repeat.

Lie face down on the floor. Reach back and press both hands to spine, palms up, interlacing fingers on lower back. Rest your forehead on the floor (not shown). Contract glutes and lower back to list chest one to three inches off floor; exhale as your raise your body. Look down to keep neck in line with the rest of spine. Hold for three counts; lower and repeat.

Boost The Burn: Lift legs as you raise chest. Lengthen by reaching ribs and legs away from center as you lift. To add resistance, place 2- to 5- pound weight to your chest with hands. Hold chest list for five counts or more.

A. Lie facedown and prop your body up on your toes and forearms, torso lifted off the floor. Look down to keep neck in line with spine. Pull belly button in toward the lower back and maintain horizontal line from heel to head.

B. Rise higher by shifting weight onto hands and straightening arms. Keeping body rigid, abs contracted, slowly raise left leg. Hold for three counts, then lower. Lean back onto forearms, then lower to the floor and rest. Repeat, rising and lifting alternate legs. Do 5 repetitions on each side.

Boost The Burn: Hold at each level for 10 to 20 seconds. Breathe throughout.