MUSCLES ENGAGED Back (middle) Middle back muscles are very important as they help to support and strengthen the core muscles at the front of your body. Biceps Biceps are the pair of muscles on the front of the upper arm connecting the shoulder to the elbow. Your biceps are used in everything from turning a doorknob to lifting heavy items. Strengthening your biceps can greatly reduce the "flabby arms" look. Equipment Used Resistance Band n/a Exercise Instructions Step 1 Start in a standing position with your feet shoulder width apart while holding a band in one hand. Step 2 Keep a soft bend in your knees and your spine in a neutral position as you pull the band to your lower hip. Step 3 Return your arm to the starting position and fully extend your elbow before the next rep.