Get More Bang for Your Strength Training Buck by Being Eccentric

In honor of the recent passing of Robin Williams, one of the most eccentric entertainers to have graced the screen in my lifetime, I decided to honor eccentricity in today’s article.

As early as I can remember doing weight bearing exercise, I always emphasized the muscle-shortening part of the movement, or what seemed like the hard part of the exercise. If I was doing a push-up, my effort was on pushing myself off the floor. Then I quickly lowered myself down and began the next one. If I was doing a sit-up, my effort was on sitting up. Then I’d drop right back to the floor. If I was doing biceps curls with dumbbells, I was focused on raising the weight and bringing by hand toward my shoulder. After each curl, I’d let my arm drop without much restraint, and then start the next rep. This type of exercise focuses on what’s called the concentric aspect of muscle work – the part where muscle fibers are shortening.

There’s another kind of work that our muscles do in exercise, which is to restrain the re-lengthening of the muscle after a concentric contraction. This is called eccentric (“ek-sentrik,”) contraction, and it has unique benefits and even some advantages over concentric exercise. In the three examples in the previous paragraph (pushups, sit-ups, and biceps curls) the part of the exercise I wasn’t paying attention to – lowering my body in the push-ups, lowering my body in the sit-ups, and lowering my forearm in the curls – was the eccentric phase.

In studies comparing strength and muscle mass gains between concentric-only and eccentric-only exercise, the two forms produced about equal results. [1] The main difference was that participants found eccentric exercise easier to do. One recent study found that women who did 30 minutes of eccentric exercise per week experienced an improvement in their Resting Energy Expenditure – a measure of how many calories the body burns in a 24 hour period while resting – and their fat oxidation rate – the breakdown of fat into energy. [3]

Because it’s easier to do eccentric exercise versus concentric, many studies utilized considerably more weight for the eccentric phase than the participants could possibly lift concentrically. For example, if a 100 pound barbell is the most weight you could press off your chest, it’s likely that you could (eccentrically) lower 125 pounds or more to your chest.

However, because of the heavier loading and high number of reps certain studies have employed, some researchers concluded that eccentric exercise has a greater potential for muscle damage than concentric exercise. [2] However, this is not to be expected with a regular exercise program where you’re using an amount of weight that you are able to manage in the concentric phase. And, of course, providing that you emphasize good form above all else.

Intense eccentric exercise tends to produce significant muscle soreness, and possibly weakness and reduced range of motion, beginning about 24 hours later. However, in a paper by Dr. Priscilla Clarkson of the Department of Exercise Science at my alma mater, UMass Amherst, she states, “The damage that is induced by these exercises is completely repairable in a short amount of time.” Clarkson states that even after high-force eccentric exercise, within 7 to 10 days, muscle function is fully recovered. Furthermore, and this is most interesting: “The damage also results in an adaptation in the muscle making it more resistant to damage from subsequent strenuous exercise.” In subsequent bouts of high-force eccentric exercise, study participants experienced better performance, quicker recovery, less muscle damage, and less soreness afterwards. [1]

Luckily, even if you stay on the safe side and engage only in moderate eccentric exercise that produces little muscle damage, this “training effect” still occurs. No such adaptation occurs with concentric training. [1]

So, what do you do with this information? The simplest and most immediate way to apply this research to your fitness regimen is to start placing equal emphasis on the concentric and eccentric phases of the exercises you do. Don’t switch to only eccentric training, because eccentric and concentric exercises benefit us in slightly different ways. A balance is best. Spend just as much time on the eccentric phase as you do on the concentric. As a starting point, I recommend at least 3 seconds on each phase for each rep. For example, if you’re doing a pushup, that means it should take you 3 seconds to go up and 3 seconds to go down. If you’re doing a squat, most people can start by taking 5 seconds to go down from standing to squatting and another 5 seconds to rise again.

Give it a try. See how your body responds differently to this kind of workout, versus one with a typical concentric emphasis. And, yeah, expect to be sore at the beginning.

Be well,

Dr. Peter Borten

[1] Clarkson, Priscilla. “Eccentric Exercise Testing and Training.” Department of Exercise Science, University of Massachusetts at Amherst, n.d. Web. 10 Dec 2011. <http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19940023860_1994023860.pdf>.

[2] Sayers, Stephen P., Priscilla M. Clarkson, Pierre A. Rouzier, and Gary Kamen. “Adverse Events Associated with Eccentric Exercise Protocols: Six Case Studies.” Medicine & Science in Sports & Exercise 31.12 (1999): 1697-707.

[3] Paschalis, V., M.G. Nikolaidis, et al. “A weekly bout of eccentric exercise is sufficient to induce health-promoting effects.” Medicine & Science in Sports & Exercise. 43.1 (2011): 64-73. Web. 12 Dec. 2011. <http://journals.lww.com/acsm-msse/Abstract/2011/01000/A_Weekly_Bout_of_Eccentric_Exercise_Is_Sufficient.9.aspx>

2 thoughts on “Get More Bang for Your Strength Training Buck by Being Eccentric

  1. Do you know anyone in Portland, OR who is teaching essentric workout classes?

    1. Hi Martha,
      Sorry, I don’t. But I’m sure such a thing MUST exist in Portland.
      Good luck & be well,
      Peter

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