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 TRX Trainer Suspension training is a type of fitness training that uses a system of ropes and webbing called a "suspension trainer" and uses your own body weight as resistance. Exercise Instructions Step 1 Hold the TRX in one hand and place your other hand higher up on the strap. Keep a soft bend in your knees, your feet shoulder width apart and your core engaged. Step 2 Lower your body with full control and rotate open into a t-bar position pointing towards the floor. Step 3 Pull your body back up to the starting position and reach up the strap with your other arm. Make sure that you keep tension in the TRX strap throughout the entire exercise.