Abs workout

This routine concentrates on every part of your abdomen, as well as your obliques. It's great for people with lower-back pain or a weak core, and will help to improve your posture. Wilson recommends doing these exercises at least four times a week and bringing your heart rate up before beginning. Rest for 10 to 20 seconds between each set; more than that, and your heart rate will drop.

Equipment needed: A mat, a medicine ball and one free weight (5 to 15 pounds).

Leg lift with medicine ball
(1) Lying flat on your back, place the medicine ball between your ankles.
(2) Keeping your upper body still, extend your legs toward the ceiling. Form a 90-degree angle with your body.
(3) Lower your legs to the floor.
Repeat the movements ten times; perform three sets.

Windshield wipers
(1) Lying on your back with your arms at both sides, lift your legs toward the ceiling, creating a 90-degree angle with your body.
(2) Keeping your ankles together and upper body still, lower your legs to the right, pivoting from your hips. Bring your legs back to center, lower them to the left, then return to the center.
Repeat the movements in (2) ten times; perform three sets. For added difficulty, place a medicine ball between your ankles.

Weighted sit-ups
(1) Lying flat on your back, bring your knees toward your body while keeping your feet flat on the floor.
(2) Holding a five-pound weight behind your head, lift your upper body to a seated position.
(3) Return to position (1).
Control the downward motion by contracting your abdominal muscles.
Repeat the movements ten times; perform three sets. For added difficulty, increase the weight size and/or perform the exercise on an bench set to a decline.

Weighted body rotations
(1) Lying on your back with your legs flat on the mat, extend your arms over your head, holding a free weight.
(2) Keeping your arms extended, lift your upper body until you form a 90-degree angle with your legs.
(3) Still gripping the weight, lower your extended arms over your head until they're parallel with the floor. Twist your trunk to the right, back to center, then to the left and return to center.
(4) Raise your arms above your head and return your lower body to position (1).
Repeat the movements 15 times; perform three sets. For added difficulty, increase the size of the weight and/or perform the exercise on a bench set on a decline.

Scissor kick pass-throughs
(1) Lying flat on your back and holding a medicine ball on your chest, contract your abs and raise your shoulders off the floor.
(2) Extend your legs toward the ceiling, creating a 90-degree angle with your body.
(3) Maintaining straight legs, lower one leg until it's hovering above the floor. While alternating legs in an expanded scissor position, take the medicine ball and pass it around the outside of your upright leg, and back through the center. As your legs alternate positions, pass the medicine ball around the other leg to form a figure eight.
Repeat the movements in (3) 20 times; perform three sets.

Around the world
(1) Lying flat on your back with your legs straight and holding a medicine ball in one hand, contract your abs and raise your shoulders off the floor.
(2) As your upper body crunches in, lift your legs up and bend your knees until your thighs form a 90-degree angle with your body. Your calves should be parallel to the floor and your thighs should be touching each other.
(3) Pass the medicine ball around the outside of your thighs and back to center.
(4) Release the crunch and lower your legs until your feet tap the floor.
Repeat movements (2) through (4) ten times; perform three sets.