Tone your upper body this summer with Olympic Sports and Ftiness as we bring you a deal that focuses on simply enhancing your looks and shaping up your physique. Pulling against the resistance helps improve firmness and strength of your upper body, includes workout for chest, back, shoulder, biceps, triceps, wrists, arms, and grips. Chest expander is a very old technique which is very effective and still used today to build upper body muscles. The shoulder muscles consist of three main groups: the posterior, the middle and the anterior. Using the chest expander, you will be able to activate and exercise all muscle groups.