Intermediate Routine

Spinal Lift (3 to 5 reps)
This exercise teaches your abs and lower back to work in sync with each other while stretching and strengthening both muscle groups. This also increases posture awareness, and stretches the backs of your thighs.

1. Sit up tall with your legs out in front of you and comfortably apart. Gently flex your feet. Extend your arms out in front of you, shoulders relaxed, palms facing in toward each other. Pull your abs in toward your spine. (Note: If you have trouble sitting up straight, bend your knees slightly.)
2. Pull your abs inward even more, tuck your chin to your chest and round forward so your fingertips move toward your toes. Hold a moment and then roll back up to your tall starting position, trying to feel each vertebra stack directly on top of the one beneath it as you go. Hold a moment before moving into the next rep.

The Folding Chair (8 to 15 reps)
This is an intense, all-around ab toner.

1. Sit tall with your hands on the floor behind you and your legs bent and held up off the floor; in this position you are balanced on your butt and palms.
2. Bend your knees in and move your chest forward so that they move toward each other and come together just over your hips. Hold a moment and then return to the start.