As you lower and push the barbell during the bench press, the muscles in your body have to work both concentrically and eccentrically. When they’re contracting eccentrically, instead of the muscle tissue squeezing together, it’s actually elongating. An eccentric contraction is usually involved in controlling the lowering of a weight against resistance. The bench press, being a compound exercise that requires movement at both the shoulders and elbows, works multiple muscles in the upper body.
The primary muscle recruited during the bench press is your pectoralis major, which is the largest muscle in your chest. It’s responsible for squeezing your upper arms together toward the centerline of your body, which is anatomically referred to as horizontal adduction. Your anterior deltoid, which is the front of the largest muscle in your shoulders, is responsible for lifting your arms upward and in front of you as you push the bar over your chest. The triceps brachii, which run down the back of your upper arms, straighten your elbows.
As you lower the barbell toward your chest, your pectoralis major, anterior deltoid and triceps brachii are contracting eccentrically. Because of the pull of gravity on the bar, instead of concentrically contracting to squeeze your arms together, lift your arms up and straighten your elbows, they’re eccentrically contracting to control the bar down and prevent it from collapsing into your chest.
Eccentric Loading the Bench Press
You can modify how you do the bench press to focus more on the eccentric work of your chest, shoulders and triceps. To do so, lower the barbell as slowly as you can to your chest. Push the bar up at a normal cadence, but always lower it at a slow speed. If you have a partner, you can have her increase the amount of load you have to control during the eccentric component of the exercise by gently pressing down on the bar as you slowly lower it to your chest. A 2002 study published in the "Journal of Strength and Conditioning" found that increasing the load during the eccentric component of the bench press significantly increased the amount of weight that can be lifted during the concentric phase. The head researcher, Brandon K. Doan of Ball State University, suggested that the result indicates that those looking to increase the amount of weight they can bench could see significant results by eccentric loading.
If you decide to focus on eccentrically contracting your chest, shoulders and triceps during the bench press, keep in mind that you’re likely to feel it the next day. According to Dr. Uwe Proske of Monash University in his 2001 article published by "The Journal of Physiology," eccentric exercise causes soreness and stiffness the day after a workout because it causes more significant damage to the muscle fibers. The discomfort can set in a few hours after the workout is completed, but you will feel the most significant pain about 48 hours afterward.
Kim Nunley has been screenwriting and working as an online health and fitness writer since 2005. She’s had multiple short screenplays produced and her feature scripts have placed at the Austin Film Festival. Prior to writing full-time, she worked as a strength coach, athletic coach and college instructor. She holds a master's degree in kinesiology from California State University, Fullerton.