Set up a cable station at head height. Stand with the cable on your right hand side and grip the end of the cable firmly in your left hand with your arm bent. Position your feet shoulder width apart, with knees slightly bent for stability. Keeping your elbow still, pull the cable down until your forearm is parallel to your body, squeezing your tricep as you do so, keeping your elbow close to your body and your wrists locked in a straight position. Pause for a count of one then return to the start position - again moving your forearm only. Repeat all the required reps on one side then alternate.