Hold each end of a long resistance band in your hands. Place both feet onto the middle of a resistance band and stand with them just wider than shoulder width apart. Stand tall, brace your core and avoid arching your back. Start with your arms extended down by your thighs. Keeping your elbows and upper arms still, bend at the elbows and curls your arms upto towards your chest. Exhale as you do this and squeeze your biceps. Reverse the movement to return with control to the start positon, inhaling as you do so. Repeat for the required number of reps (or time).