Plank Row

Plant your hands and feet on the ground in a push-up position, holding a dumbbell in each hand. Your whole body should feel tight — shoulders packed, core braced, glutes squeezed. That tension is the whole point. Now row one dumbbell up, driving your elbow back and bringing the weight to your ribs, while your hips stay dead still. The anti-rotation is what's working here; you should feel your obliques fighting hard to keep your torso from twisting. Switch sides. The moment your hips rotate or your shoulders shrug is the moment you've lost the position.