Eccentric Exercise: What I’ve Been Missing

by Hilary Froman, PharmD

My entire life, I’ve ignored the second half of my workout…

When someone first hears the term eccentric exercise, they might imagine a quirky, “eccentric” aunt participating in one of those fad exercises -doing aerobics in high heels, or running around on Kangoo Jumps (springs for your feet). Eccentric exercise shares no relation to these exercise fads, but don’t ignore it – it could be your answer to many exercise problems.

What is eccentric exercise?

Muscle contractions occur in three ways: isometric, concentric, and eccentric. During an isometric muscle contraction, the muscle contracts without changing length. A concentric muscle contraction makes a muscle shorten. And during an eccentric contraction, the muscle lengthens as it contracts.

Eccentric exercise/training focuses on the eccentric portion of a muscle contraction – for example, taking five seconds to lower your hand during a bicep curl instead of just dropping it-not as wild as doing aerobics in heels, but much more useful.

Why you should care:

1. Strengthening happens faster: Because you can handle more resistance/weight with an eccentric contraction, you get stronger faster. Athletes and avid exercisers who have plateaued can increase athletic performance by focusing oneccentric movement. A study from 2008 demonstrated just that. Researchers found an exercise program focused on eccentric rehabilitation developed larger and stronger quadriceps and gluteus muscles when compared to a standard rehabilitation program after ACL-reconstruction.
2. Better injury prevention: When you think of eccentric exercises, think braking actions: slowing down when running, lowering yourself into a chair, and walking down a hill. It turns out that being able to control or brake an action is critical for injury prevention. A huge number of injuries occur because of failure to control those eccentric movements. Strengthening eccentric movements makes a lot of sense then for injury prevention. A 2011 study included 942 soccer players separated into an eccentric training program and a standard training program. The eccentric group had significantly fewer new and recurrent hamstring injuries.
3. It requires less energy: Less energy means less oxygen needed, and therefore decreased demand on the lungs and heart. This makes sense for strength training in patients with breathing or heart conditions.
4. The benefits are far-reaching: After an injury, we’re supposed to rest. Researchers looked at ways to speed recovery and return to sport. They studied the effects of exercising just one leg to observe the effect on the injured leg. They discovered that eccentrically exercising the quadriceps of one leg increased the strength of the quadriceps in the opposite leg -pretty cool. The strength gain in the unexercised leg was not as great as the exercised one, but during an injury, any little bit helps. No significant strength gains in the unexercised leg were observed in the concentric group.

What does this all mean?

Taking a backseat to concentric movement in research, eccentric movement still has a long way to go in proving itself a fundamental element of prevention and standard rehabilitation regimens. The potential is great, and it is too cost-effective to ignore. I am excited to see new research in the future, and until then, I am going spend more time lowering my arm during a bicep curl.

References

1. Lindstedt SL, LaStayo PC, Reich TE. When active muscles lengthen: properties and consequences of eccentric contractions. News Physiol Sci 2007; 16: 256-261.

2. Gerber JP, Marcus RL, LE Dibble, et al. Effects of early progressive eccentric exercise on muscle size and function after anterior cruciate ligament reconstruction: a 1-year follow-up study of randomized clinical trial. Phys Ther 2009; 89:51-59.

3. Lepley LK, Palmieri-Smith RM. Cross-education strength and activation after eccentric exercise. J Athl Train 2014 Aug 12. [Epub ahead of print]

4. Peterson J, Thorborg K, Nielsen MB, et al. Preventive effect of eccentric training on acute hamstring injuries in men’s soccer: a cluster-randomized controlled trial. Am J Sports Med 2011; 39(11): 296-303.

5. Wasielweski NJ, Kotsko KM. Does eccentric exercise reduce pain and improve strength in physically active adults with symptomatic lower extremity tendinosis? A systematic review. J Athl Train 2007; 42(3): 409-421.