Pullups are an exercise that work your back, biceps and forearms. Pullups also work the muscles on the back of your shoulders and some of the small muscles that help stabilize your shoulders. Pullups can be used to build strength, muscular endurance and transfer well over to activities such as climbing. Consult your physician before beginning any diet or exercise program.
The latissimus dorsi are the widest muscles of your back and are used in many upper body exercises, even the bench press. These muscles are the agonists, or prime movers in the pullup. These muscles are the largest muscles of your upper body and provide stability when pressing overhead, any movement in which your torso rotates or bending over. It is important to train through a full range of motion to properly recruit your latissimus dorsi. Never bounce out of the bottom of the repetition in an attempt to achieve a greater range of motion or make the exercise easier. This leads to injury.
Biceps and Forearms
Your biceps are worked heavily during pullups. The function of your biceps is to flex the elbow, so the greater the range of motion during your pullup, the greater the work your biceps receive. Your forearms work to hold onto the bar. While some people use straps, not only does this limit the amount of grip work you are receiving, it exposes you to injury should you slip. You do not want to wind up dangling from the bar with all of the strain being delivered to your rotator cuff. Avoid using straps on this exercise.
The posterior deltoid, or back of your shoulder, is active in retracting your upper arm every time you pull yourself up. This muscle helps stabilize your shoulder during pressing motions, and is often under-trained in many bodybuilding-type routines. Small muscles under the shoulders and the middle of your back such as the rhomboids are also worked, but only if you pull yourself far enough up to retract your shoulder blades. This is another reason to use a full range of motion.
The chest is not worked at all during pullups. The function of the pectoralis major, the large muscles of your chest, is to adduct the humerus. This means they move your upper arm into the midline of your body. This does not occur at all during pullups, regardless of which grip you are using or what range of motion you manage. Bench press and fly-type exercises work the chest. If you do not have access to weights and want to work your chest, perform a set of pushups between each set of pullups.
- "Journal of Strength and Conditioning Research"; Effects of Variations of the Bench Press Exercise on the EMG Activity of Five Shoulder Muscles; 1995
- "Dynamic Medicine"; Variations in Muscle Activation Levels During Traditional Latissimus Dorsi Weight Training Exercises: an Experimental Study; George J. Lehman, et al.; June 2004
- "British Journal of Sports Medicine"; Diagnosis and Management of Superior Labrum Anterior Posterior Lesions in Overhead Athletes; G.D. Abrams, et al.; December 2010
- "Journal of Strength and Conditioning Research"; Surface Electromyographic Activation Patterns and Elbow Joint Motion During a Pull-up, Chin-up, or Perfect-pullup™ Rotational Exercise; J. W. Youdas, et al.; December 2010