As part of our fitness lexicon, there are 3 terms that are often read in descriptions of strength exercises, and that are essential to know: eccentric, concentric, and isometric.
The three terms describe a certain way of working of the muscles, each of which is responsible for a certain part of the repetition. The synonyms positive-dynamic and negative-dynamic are often used for concentric and eccentric. However, positive and negative should not be understood as good and bad, but as a description of the direction of movement.
In summary, it can already be said at this point that strength can be divided into 3 components of movement in weight training:
- Concentric work: Overcoming resistance
- Eccentric work: counteracting resistance
- Isometric work: holding resistance in one position
Definition of Concentric, Eccentric and Isometric
Concentric movement = positive part of the movement = overcoming = muscle shortening = increasing the speed of movement.
Eccentric movement = negative part of the movement = yield = stretching / muscle stretching = slowing down the speed of the movement.
Isometric = static holding work = muscle remains equal in length = no movement.
Example of Concentric and Eccentric Muscle Work
I have not included the isometric working method in the table because there is no movement here. In the case of the chin-up, it would be an isometric muscle work to stay in any position of this. The muscle then performs isometric clamping work. Even if there is no movement, different levels of tension are produced in the muscle, as the exerciser does not usually constantly exert the same force on the immovable object.
Use in Bodybuilding and Weight Training
There are training systems that have now focused on certain ways of working. Some muscle building bodybuilding programs focus on the eccentric strength component while others focus on the concentric strength component.
Eccentric phase boost is used in many intensity programs. Isometric training is also a great option to choose. This post will help you explain and define the terms of the 3 components of force.
Eccentric Training
In eccentric training, the negative phase of the exercise is specially trained. This has the advantage that significantly higher loads (weights) can be used than for the positive phase of the repeat. The “lowering” with a high weight is performed especially often with chin-ups and dips, since here you can work without a training partner.
Advantage of eccentric training: Due to the high training weights that can be used, it is possible to significantly increase the training volume. The eccentric phase also causes significantly more muscle trauma which is decisive for the hypertrophy process (muscle building).
Eccentric strength training in practice
With dips and pull-ups, the weights in training can be significantly increased by adding additional weight with the help of a weight belt.
With the help of a normal training bench, you can reach the upper position of the exercise and then only train the eccentric phase (lowering yourself). For exercises like the bench press, you also rely on the help of a training partner or observers who, after lowering the weights, will help you return to the starting position.
Weight training, which is well above normal training weight, should only be used very sparingly and only by experienced strength athletes who have this intensity and have excellent regenerative ability.
The eccentric phase can also be emphasized in a training plan by consciously changing the tempo or cadence. This approach can also be implemented by beginners by extending the eccentric phase of the rep to 5 seconds, for example.
Isometric Training
Isometric training describes a type of training in which you pull on an object or press against something in a static position, but it does not move.
The muscle fiber is not shortened or stretched during isometric training, hence the name Iso (= equal to) Metric (= relative to measurement). During isometric training there is a lot of lactate, which leads to excessive acidification of the muscles.
Isometric Strength Training in Practice
Isometric pushing exercises force against a stationary object, such as a wall. In isometric traction exercises, for example, you pull on a rope that cannot yield.
Holding a chin-up bar in a certain position is also an isometric exercise, or staying in any position in the squat.
Pure isometric training is very rare in bodybuilding, but it is used quite often as an intensity technique. Isometry is generally integrated into training as follows:
- With each repetition, stop in a certain position and hold the weight for 5-10 seconds or press against the weight.
- After the last rep, hold the weight in a certain position for as long as possible or press against the weight.
- After regular workouts, do a static rep and hold the weight for 30-60 seconds or press against the weight.
