Start with your upper back supported by a padded surface behind you (such as a chair) and a dumbbell resting across your hips. Place the balls of your feet together and let your knees fall out to the either side. Grip the dumbbell firmly in each hand. Focusing the tension in your glutes, drive your hips up to full hip extension, exhaling as you do so. Keep your chin tucked and eyeline looking forward throughout the movement. Pause for a count of one when your hips reach full hip extension, keeping the tension in your glutes and then return with control to the start position, inhaling as you do so. Repeat.