Start in high plank with straight arms and place hands right below shoulders and balance on toes. Keep knees bent for beginners and straight legs for more advanced. Then twist to one side reaching the top arm right up to the ceiling. It's challenging, it's yoga-y and it tones your abs like nobody's business! Beginner to advanced. 

A great exercise to whittle your waist! Lie on your back and either hang onto something stationary behind you or place hands, palms down at hips. Tuck in chin and bring legs up to ceiling. Push up with one leg up to the ceiling and now add your hula girl twist in that same hip. Twist those hips and add some attitude in your twist! Now repeat on the other side and alternate. Beginners to intermediate. 

Pick a large, firm ball and lie down with your stomach on a ball and bring hands onto floor then push yourself forward so that your knees and shins and feet are still balanced on ball. Tuck in tummy muscles tight and bring knees up high to your chest. Think of lifting your bottom up high to the ceiling. Try it, it's challenging! Intermediate to advanced. 

A challenging variation of the inch worm on ball. Lie tummy on ball and walk hands forward on the floor. Maintain knees, shins and feet on ball. Keeping abs super tight. Using feet, pull ball in towards chest at the same time pointing your bottom up towards ceiling into a pike position. It's like gymnastics on the ball! It's even fun! Intermediate to advanced. 

In a sitting up position with heels anchored on floor and posture perfect, take a medicine ball and twist side-to side. Tap or bounce the ball on either side for added tummy toning! And bonus - it works your arms too! Intermediate to advanced.