Sculpt your shoulders, arms, abs, and hips with this total-body plank variation.
How to do it: Grab a dumbbell in your right hand and sit on your left hip, left leg extended out straight under you, foot flexed. Bend your right knee and place your foot flat on the floor just behind your left leg. Place your left hand directly below your shoulder and in line with your left hip to support your body. Bend your right elbow so that it's lightly touching your left thigh, palm facing forward. Press the weight straight up, extending your arm to the ceiling as you lift your hips off the floor. Your left leg should stay straight with the edge of your foot on the ground the entire time. Push up with your right leg (knee stays bent, your right heel lifts slightly) for support. Slowly lower back down, bending your arm back to start, and lightly tap your left hip to the floor (don't rest on it at the bottom). Immediately repeat.
Form tip: Instead of using your supporting arm to lift, focus on lifting up with the bottom side of your torso to really engage your core muscles.
60-second cardio burst: Run in place again, but this time position your feet slightly wider than your hips (as if you were standing in two tires), and push side to side as you drive your knees up. Continue for 1 minute.