What Is Eccentric Resistance Training?

JEN WEIR RECENTLY PUBLISHED A PIECE ON COMPETITOR.COM that explained why runners should perform eccentric resistance exercises. I was reminded that resistance exercise = strength training just last month. But what is eccentric resistance training? I had not heard or seen that term before. Her article explains, “Eccentric training is simply capitalizing on the eccentric action of muscles, which occurs when tension is applied to a muscle as it lengthens.” But her explanation did not help me fully understand the concept.

The American College of Sports Medicine further explains in a PDF titled Eccentric Resistance Exercise for Health and Fitness.   “Muscle contractions involve shortening and lengthening while the muscle is still producing force. The phase of contraction that occurs when the muscle shortens is concentric, whereas the phase of contraction that occurs as the muscle lengthens is eccentric.” The information sheet goes on to explain that eccentric muscle strength “is especially important for balance, mobility, and physical functions such as walking DOWN stairs or LOWERING objects to the ground.” 
 
Most exercises have traditionally focused on strengthening muscle in the concentric phase of contraction and only recently has more emphasis been placed on “eccentric”, or “negatives” as these exercises are commonly called. This can lead to an imbalance between concentric muscle and eccentric muscle strength, which becomes evident when MORE eccentric muscle contraction is needed BEYOND training preparations, such as long downhill runs within a distance race like a marathon. This kind of muscle action is required for the body to maintain control in a rapid, gravity-aided descent. It seems the Boston Marathon is a classic example of a “downhill” marathon that runners must prepare for, or at least be cognizant of in training, in order to stick with a race day strategy.
 
Another Competitor.com article describes why downhill racing can be so tiring.  “Eccentric contractions are much more costly from an energy and wear and tear perspective,” says Dr. Ivo Waerlop, D.C. “Running downhill requires lots of eccentric contraction, especially in the quadriceps and lower leg muscles.” Mastering the downhill with proper form will put less stress on your legs and can help you make up time in your next race.”
 
There are various ways to prepare for such races. Some of those methods are outlined in a Runner’s World item, “Avoid Downhill Disasters: How To Train For a Downhill Marathon” by Brian Metzler, listed next (not in the order in the article) to include:
a) preparing your body with strength training that hits the core and lower body muscles
b) incorporating downhill running in your training plan, and
c) working on perfecting a good downhill form that avoid over-striding

Surprisingly, also on the list is d) incorporating UPHILL running. According to Metzler it will strengthen all the “backside” muscles that extend from the gluteal group to the hamstring and calve groups to the foot fascia, so that they can assist the quadriceps muscle during downhill movement. Other help can come from changing to shoes with more cushioning, training on trails/barefoot to strengthen feet and lower legs and improve proprioception (your “feel for the road”), and increasing the length of a taper (to rest the legs sufficiently before a long distance race).

Jason Karp has an excellent article in Competitor.com “Downhill Training workouts to Improve Speed, Control“.  Jen Weir (her article started my search to learn more), also provides advice in it.

I searched the medical literature and found research articles that examine eccentric exercise, but could not find one that was directed at my entry-level of understanding or that reviewed the topic generally or in relation to running. But I received the impression that investigation into this specific type of resistance training was possibly at an early stage and garnering increased interest. One of the exercises studied in athletes is the Nordic Hamstring Exercise, also mentioned in the Weir article. I found a demonstration on YouTube that looked “dangerous” for less trained individuals (myself as a model; I could strain/hurt something) but then located one that appeared to more “safely” utilize a Swiss Ball to help maintain control during the exercise performance.
 
I am not yet sufficiently educated on the subject to confidently endorse other exercises recommended by the various articles. The American College of Sports Medicine position seems to indicate there is a place for incorporating this specific type of exercise into training. There may be more discussion in the popular sources so I thought it was worth introducing to you. I hope to learn more and ease into some downhill training. WARNINGS are given in each and every article about how eccentric training leads to a moderate amount of MUSCLE DAMAGE (which is what leads to strengthening!) such that no more than one session per week is advised or NEEDED!
If you have information that been helpful to you, please share!

RUN HAPPY!

http://running.competitor.com/2016/02/training/why-runners-should-do-eccentric-training_145368

https://www.acsm.org/docs/brochures/eccentric-resistance-exercise.pdf?sfvrsn=4

http://running.competitor.com/2014/07/training/perfect-your-downhill-running-form_52804

http://www.runnersworld.com/race-training/avoid-downhill-disasters

http://running.competitor.com/2014/03/training/downill-running-workouts_70437

https://www.youtube.com/watch?v=vynsCfHZ69A (Nordic hamstring with Swiss ball)

https://www.youtube.com/watch?v=TFYVfGJtT1A (Nordic Hamstring)