Hold the dumbbells down by your side with palms facing each other. Make sure your back is straight, engage your core and lift your chest up.
Throughout the entire exercise your upper body is going to remain perfectly upright. Step forward with your right knee and lower yourself until your thigh is parallel with the floor.
Then, pushing through the ball of your foot, push yourself back to the starting position. Do as many as you can on one leg, then switch to the other.