Stand with your feet shoulder width apart with a flat back and your core braced. Place short resistance band just above your knees and rack one dumbbell at your shoulder, keeping your elbow pointed forwards. You can take your opposite arm out to the side to provide a counter-balance. Keeping your chest up, bend at the knees and drive your hips back and down like you're sitting on a chair. Lower slowly with control until your thighs are parallel to the floor, inhaling as you do so and pushing your knees out against the band. Pause at the bottom, then extend your legs and drive your hips forward to return to the start position, exhaling as you do so. Repeat all the required reps (or time) on one side before changing to the other.