Eccentric Contractions and Muscle Hypertrophy
First off lets define the two terms that we are looking at prior to examining their connection and relevance to the progression of your training. An eccentric contraction is the part of the movement in an exercise in which the muscle is contracting but lengthening simultaneously. This is opposed to a concentric contraction in which the muscle is shortening while contracting. Contrary to popular belief the eccentric contraction is actually damage within the muscle. This muscle damage is actually necessary for muscle hypertrophy.
Ok ladies, before you get all crazy and worried that you are going to get big from lifting weights, STOP. Because you will not ever physiologically be able to look like a man from lifting weights no matter how awesome your genetics are. Looking like a man comes from hormones that you do not have, and will not have unless you are taking pharmaceuticals that are altering your normal hormonal levels among other things. Hyperplasia is the formation of new muscle fibers that is usually a product of ergogenic aids. Hyperplasia, occurring naturally within the body is in fact extremely rare even among elite athletes such as Olympians. For some of us this is bad news, but for the average woman, who is muscle-phobic for some reason I will never understand, it is good news. That being said, you need to lift heavy and hard to induce muscle damage and repair that will result in muscular hypertrophy. Muscle hypertrophy is not the same as hyperplasia. Hyperplasia is the formation of new and additional muscle fibers while hypertrophy is simply the enlargement of those muscle fibers that you already have. So, muscular hypertrophy, how do you get this, how do you do this and what the heck am I talking about?
Ok so, back to the note at the beginning concerning eccentric and concentric contractions. The eccentric contraction is the part of the exercise that induces muscular damage that will ultimately result in muscular hypertrophy after the muscle is broken down and repaired. For example, when pulling yourself up in a pull-up that would be concentric and lowering yourself would be the eccentric portion. There is actually an entire “school of thought” or theory, which ever you would like to call it, based entirely on the eccentric contractions of exercises. This is the entire idea behind Arthur Jones and the whole concept of using negative reps as a stimulus to induce muscular damage and thus hypertrophy. Eccentric contractions are the nerd term for negative reps or negatives. Technically, you are strongest in an eccentric contraction, and can actually lower a heavy weight than you could lift and with more control. Also, technically you could perform entire workouts only of negatives reps and maximize muscular damage because you would not be expending energy on the concentric phase of lifting the weight back up. Weird concept to think about but it is actually true. This is where the idea of the entire line of Nautilus equipment was derived! However, many people as they always will, have opinions about whether this truly works or not and is actually realistic for training. However, that being said, there is not question whatsoever that the muscle damage needed to induce hypertrophy does without a doubt occur during the eccentric phase of any exercise. Some exercises are more conducive to negative reps opposed to others.
It would be beneficial for you to focus on the eccentric portion of your exercises while training. Always keep the negative phase controlled, lowering the weight in a slow fashion and not a jerky movement. You can also intensify or alter your training by playing with the length of the negative portion of a rep within a set. For example in a leg extension, you can concentrate on elongated your negatives and instead of simply lowering and raising the weight in a repetitive nature, you can add counts to your negative. Eight seconds up and eight seconds down, or 5 seconds down and then directly back up or something of that nature. This is also related to the concept of time under tension.
Ultimately it comes down to the variance within your training program. This I will discuss in future articles but it is important for you to read this article to begin to understand the basics and backgrounds from where everything is derived.
Photos from:
http://blog.top10workouts.com/?tag=eccentric-contraction
http://www.geneticwar.com/training/change-the-tempo-for-faster-gains/
http://www.burlingtonsportstherapy.com/blog/pulled-hamstring/
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