SWISS-BALL KNEE TUCK
(works transverse abdominis, obliques, rectus abdominis)
Assume the pushup position with your shins on a Swiss ball and your hands on the floor, shoulder-width apart and beneath your shoulders. Keeping your head down and your abs drawn in, slowly pull your knees toward your chest. (The ball will roll slightly forward.) Try to keep your hips down to maintain the stress on your abdominals. Pause, then straighten your legs to roll the ball back out behind you.
Watch Your Form: Keep your belly button pulled in toward your spine. This engages your transverse abdominis, which helps protect your back.
(works obliques, transverse abdominis)
Use a weight that allows you to do no more than 12 to 15 repetitions. Stand with your right shoulder toward a high-pulley cable station and grab the rope or handle with both hands. Keeping your toes forward and knees bent, slowly rotate to your left as you draw your arms across and down. Pause when your hands are above your left thigh, then slowly reverse the motion. After a set, repeat the move with your left shoulder facing the stack.Watch Your Form:Don’t pull the weight with your arms or back. Keep your elbows at the same angle so your core muscles control the movement.
HANGING WEIGHTED TWIST
(works lower rectus abdominis, obliques, transverse abdominis)
Hang from a bar and have a partner place a light medicine ball between your knees. Rock your pelvis upward, then slowly raise your knees up and to the left. Slowly lower your legs and repeat, this time to the right.Watch Your Form:Raising your knees before your pelvis can cause you to engage more of your hip flexors–the muscles along the front of the thighs. Think of the move in two parts: Tilt your pelvis up first, then raise your legs.
(works rectus abdominis, obliques)
Lie on your back with your knees bent 90 degrees and your feet off the floor so your thighs are per-pendicular to the floor. Fold your hands across your chest. Slowly straighten your legs away from you and to the right. (They should end up at a 45-degree angle to the floor.) As you go, crunch your torso upward and to the left while extending your arms forward. Slowly lower yourself back to the starting position. Repeat the exercise in the other direction.Watch Your Form:Spend at least 2 to 3 seconds going up and the same going down. Rushing can disrupt your balance and force you to stop.