Stand tall with your core braced, a flat back and a dumbbell held directly overhead in your rigt hand. Step backward with your right leg. This is your start position. Bend at the knee, slowly lowering your body until your front knee is bent at least 90 degrees, whilst your rear knee should be hovering just off the floor. Inhale as you do so. Keep the arm holding the dumbbell locked out overhead throughout. Keep your torso upright the entire time and look forward. Pause at the bottom of the movement, then extend your knee as you return to the split stance start position. Repeat.