Articles

Emphasizing on Eccentric Contractions

It’s time to build bigger muscles.

Every time you go to the gym, you lift and lower the weight to build more muscle; and according to new research, you should be focusing on eccentric contractions. When you lift the weight up, this refers to the concentric contraction – when the muscle shorts and contracts. The lowering of the weight is known as the eccentric phase – when the muscle is lengthened, or lowered. You can handle a much heavier weight when lowering the dumbbell or barbell, compared to when lifting it. You can lower about twice the amount of weight you can lift.  If you want to test this for yourself, get on a smith machine and you will be amazed at how much stronger you are lowering a weight compared to starting with the weight on your chest pressing up.

Physiological Reasoning

Eccentric-only muscle contractions involve a lower energy cost for the same amount of mechanical tension. This means there’s less physiological stress when performing eccentric contractions. For example, when comparing the total calories burned, the heart rate, and blood pressure responses to lifting and lowering the same weight, lowering the weight results in a lower physiological strain. Thus, lifters can perform a greater volume of work while taxing their work capacity to the same degree.

Eccentric-only muscle contractions enable athletes to lift a larger amount of weight than during concentric-only muscle actions with the same percentage of 1RM. This may produce a higher level of mechanical tension for the same relative load, and therefore greater increases in muscle mass due to higher mechanical stress placed on the muscle.

Eccentric-only muscle contractions may cause greater recruitment higher threshold motor units, which are capable of greater muscle hypertrophy. Look at the thighs of sprinters versus those of marathon runners. They both run, but the muscle size differences are vast. Sprints are where you explode off the starting line and go as fast as possible, recruiting fast twitch, high threshold, anaerobic muscle fibers – the ones that are capable of muscle hypertrophy. Marathon runners use slow twitch, low threshold, aerobic muscle fibers that are not capable of a significant amount of muscle growth. The more tension that is placed on a tissue, the greater recruitment of fast twitch muscle fibers and greater muscle growth.

Published in the Journal of Strength and Conditioning Research is meta-analysis of concentric and eccentric training studies. A meta-analysis is a collection of research studies. The meta-analysis comprised 30 groups from 15 studies. When all the data was crunched, the researchers concluded that eccentric training might produce greater increases in hypertrophy compared to concentric training. The findings indicate the importance of including eccentric and concentric actions in a hypertrophy-oriented resistance training program, as both have shown to be effective in increasing muscle hypertrophy. So, the next time you’re in the gym, you can gain an increase in muscle size when you emphasize the eccentric or lowering phase of the contraction by lowering the weight slowly.

Schoenfeld BJ, Ogborn D, Vigotsky AD, Franchi M, Krieger JW. Hypertrophic effects of concentric versus eccentric muscle actions: A systematic review and meta-analysis. J Strength Cond Res. 2017 May 5.