The classic plank gets a gorgeous face-lift as you strengthen your core (with special attention to your obliques) and tone your shoulders, legs, and glutes. But this pose tends to scare off people with tight hamstrings and hips.
Start in a pushup position. Keeping your core engaged, shift your weight onto your left arm and foot. Rotate your torso, stack your right foot on top of your left, and raise your right arm toward the ceiling. Look up at your right hand, and hold. Slowly return to a pushup position; repeat on the other side.
From phase 1, bend your right knee and place your foot on the upper thigh of your left leg (you can assist your leg with your hand), toes pointing toward your left foot. Raise your right arm as you push your left inner thigh into the sole of your right foot to keep your hips lifted. Hold, release, and repeat on the other side.
From phase 2, reach your right arm toward your right foot (keeping your arm on the inside of your leg), and grab your big toe. Gently extend your foot toward the ceiling, straightening your leg as much as you comfortably can. Hold, slowly release, and repeat on the other side.
Starting in phase 3, draw your shoulder blades back and down and extend your right heel toward the ceiling, straightening your leg as much as possible. Press the outside of your left foot and palm into the mat and keep your core tight. Hold, then slowly release and switch sides.