This exercise provided courtesy of Billy Polson, founder and co-owner of DIAKADI Body training gym, voted best personal training gym in San Francisco by CitySearch in 2006.
This core-busting exercise demands balance and strength. Start with a basic plank position and attack it from both ends, bringing your foot up to meet the opposite hand.
Take up a push-up, or plank, position on the floor. Your hands should be under your shoulders and your feet a little further than shoulder-distance apart. Engage your abs to keep your body flat—your hips should neither fold toward the ceiling nor droop toward the floor (see Photo 1).
- From the starting position, start by bending the knee of one leg and crossing the foot under and across your body (see Photo 2). As you bring the leg under and across, lift the opposite hand off the floor. Then, extend the crossing leg until you touch the raised hand with the opposite foot. Try to keep your hips level as you do this; stabilize yourself through your abs (see Photo 3).
- Return hand and foot to the starting position and repeat using the same arm for 20 reps, and then switch arms and repeat for another 20 reps (see Photo 4).