Select the weight on a low pulley machine and grasp the single hand cable attachment that is attached to the low pulley with your left hand.
Face away from the pulley and put your arm straight down with the hand cable attachment in front of your thighs at arms' length with the palms of the hand facing your thighs. This will be your starting position.
While maintaining the torso stationary (no swinging), lift the left arm to the front with a slight bend on the elbow and the palms of the hand always faces down. Continue to go up until you arm is slightly above parallel to the floor. Exhale as you execute this portion of the movement and pause for a second at the top.
Now as you inhale lower the arm back down slowly to the starting position.
Once all of the recommended amount of repetitions have been performed for this arm, switch arms and perform the exercise with the right one.
Variations: This exercise can be performed also with dumbbells or an exercise band.