9. Side Plank

T argets: Shoulders, chest, transverse and oblique abs.

How to: Get into the side plank position with your supporting arm straight, one foot against the toes of the other (one in front of the other). Keep your legs straight and in a straight line from head to your feet. Raise the upper hand and point the fingers to the ceiling. Slowly rotate your body so that your high arm (while remaining straight) can come down and touch the floor next to the supporting hand. Return to the starting position for one repetition. When this feels easy, hold a dumbbell in the high hand. It is important to maintain planklike straightness along your spine and legs. Don’t sag or stick your butt in the air as you rotate about the shoulder. Shoot for six perfect reps on each side

10. Bridge

T argets: Shoulders. Shoulder flexibility is the most common limiter with this move. It’s also tough on the glute-hamstring-erector spinae complex of the posterior muscle chain (the muscles going up the back of your body). The challenge doubles when one foot is lifted and your hip is flexed because the entire abdominal group has to fire to maintain balance and keep the hips from dropping.

How to: In this exercise, you’ll make yourself into a bridge or coffee table by getting onto all fours—but with your belly facing the ceiling. Hands directly below shoulders, feet flat on the floor directly below your knees. All angles should be nice and square. The first step is to push your navel toward the ceiling as far and hard as you can by squeezing your butt tight; hold. For many, this will be enough of a challenge. The next stage is to lift one foot off the floor by straightening the knee. Your leg will be in line with your torso. Hold this while pushing your navel upward. If you can do this without dropping your hips, then you are ready for the last stage: Flex the hip of the raised leg so your toes are pointed to the ceiling. Do this while keeping your navel pressed high. Hold these end positions as long as possible with no sagging in the core. Any sign of a sag means that repetition is over.