Come into a half-kneeling position with your right leg elevated. Loop one end of a long resistance band around your left ankle, bringing the other end up and over behind you, gripping it firmly in your left hand. Your left elbow should be pointed directly forwards, with your forarm bent behind you. Use your right hand to support your left arm, just below the elbow joint. This is your start position. Keeping your core braced and your upper left arm still, extend your left forearm up towards the sky. Exhale as you do so, focusing on using your tricep muscle to stretch the resistance band. Pause at the top with your arm fully extended before returning to the start position. Inhale as you do so. Perform all the required reps on one side before changing to the other.