Begin by positioning yourself underneath a Smith Machine barbell whilst standing with your feet on an aerobic step block. Make sure the bar is across your upper traps and not your neck. Stand tall with your feet shoulder width apart, with a braced core and flat back. Focusing the tension in your calf muscles, slowly raise yourself up on to the balls of your feet. Pause at the top of the movement, squeezing your calf muscles and slowly return to the starting position.