Concentric, Eccentric & Isometric Muscle Contractions
A concentric muscle contraction is probably what most people are focused on, and it is what we would consider the “lifting portion” of a movement. As we lift a load, the muscle contracts, or “shortens”. A bicep curl is a perfect example, as we lift the weight, the bicep shortens to raise the weight.
An eccentric muscle contraction actually has a larger effect on muscle hypertrophy than the concentric portion, and it is often neglected by people new to lifting(and even those experienced too!). It is the “lowering portion” of a movement, where the muscle lengthens back to its relaxed state. Studies have shown that muscles are anywhere from 20-50% stronger in the eccentric. This results in greater muscle recruitment, more muscle protein synthesis, and more hypertrophy.
Isometric muscle contractions are where there is a static hold on the muscle, whether that be in the shortened, or lengthened, position. Examples of this are planks, static bicep curls and dumbbell fly holds. As we know from eccentric contractions, muscles in their lengthened position(or with varying angles close to it) provided greater hypertrophy than isometric holds in a shortened position.
But Justin, this is all gibberish, how does it apply to ME?! Well, I’m glad you asked. Nobody trains in just the eccentric, concentric or isometric positions. But here is the takeaway…MOVE WITH PURPOSE. You often hear about the mind muscle connection, where you pay attention to each step of the movement, from the beginning, to the end, through each one of the phases of muscle contraction. In my mind, they are all equally crucial. Don’t just go through the motions with the movements, become one with the weights, young apprentice, only then will you be strong enough with the dark side.
Along with your normal training, or if you hit a plateau in your muscle building journey, try incorporating exercises that focus solely on the eccentric(often called Negative’s) or throwing in isometric holds at the end of sets, to get the gains train going again at full speed.
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