Place a mini band just above your knees. Stand with your feet slightly wider than your shoulders, holding a set of dumbbells at chest level.
Drop into a squat position, pushing your hips back and bending your knees until your thighs are parallel with the floor, as shown.
While holding the squat, focus on keeping your back flat and your chest elevated, and alternate punching the weights away from your chest at a quick pace. (You can see this movement in a similar squat here.)