Negative repetitions are a very effective and profitable intensity technique. The high effectiveness of this technique is given by the high muscle tension they are able to create, by the possibility of using a greater weight than the concentric repetition and finally because the eccentric phase is the most profitable in terms of adaptation response.
Various types of contraction
The only thing the muscle fibers are capable of doing is contracting. Thanks to mechanisms that involve the intervention of the nervous system, transport of minerals and more, the sarcomere (the functional unit of muscle tissue) is shortened. When many sarcomeres are shortened, the entire muscle also shortens and therefore there is an approximation of the two muscle insertions. A muscle is unable to spontaneously stretch.
There is a release of the contraction given by the contraction of the antagonist muscle. When the bonds that shorten the sarcomere are removed and the antagonist muscle contracts then the muscle can stretch.
A muscle can only actively shorten. When muscle fibers shorten and actual muscle shortening occurs then we speak of concentric repetition or positive phase. When the
muscle fibers contract but there is no displacement of the body segments we speak of isometric repetition.
Finally, when the muscle fibers contract but the muscle lengthens, we speak of eccentric or negative repetition. There is an inverse relationship between the speed of shortening of the muscle fibers and the strength (per section of area) that the muscle is able to express. An inverse relationship means that the higher one parameter and the lower the other, concretely the higher the shortening speed is, the lower the force expressed will be. For this reason it is possible to move very sub-maximal loads with great acceleration while maximal repetitions require a longer execution time. This inverse relationship must also be applied to the isometric contraction and also to the eccentric: when the velocity is zero (isometric contraction) the force will be greater than the concentric maximum.
When the speed of contraction is negative, and therefore the muscle stretches by contracting, the force will be even greater. This principle reaches a limit when the weight is so high that it cannot be controlled: special tendon and muscle organs register too high a tension and inhibit muscle contraction. This is because excessive muscle tension can lead to damage to the muscle or tendon component.
Negative reps | risks
Before discussing the applications of this technique it is important to outline some precautions. As previously mentioned, if the load is too high, safeguard reflexes are activated which inhibit contraction in order to avoid damage. It is also true that an eccentric contraction, which exceeds the isometric force, is capable of producing a very dangerous tension that can also lead to the same damage. Negative repetitions must therefore be avoided in case of fragility or previous problems with the structures considered.
Even if you feel psychologically "frightened" by the thought of performing negative repetitions with the chosen load, it is good not to risk it. The body is able to influence what we do by placing a
he safeguards himself even by insinuating thoughts that need to be considered. It is a kind of self-defense in the face of a danger, something unconscious, which must be taken into consideration.
This aspect, however, should not be confused with an inner laziness. Other risks need to be considered:
- Stress on the central nervous system: negative repetitions are able to tax the nervous system very effectively. If you want to have a practical feedback, it is enough to see how all the subsequent series are affected by a series brought to eccentric failure. This means that the negative repetitions should be inserted with care and preferably only in the last set of the exercise. Furthermore, it is better not to use this technique with important multi-joint exercises (bench press and squat) and especially where the lumbar area is stressed (deadlifts and rowing with a barbell).
- Lack of mind-muscle connection: if this is missing then the negative repetition turns into "trying to resist the load with the whole body". At this point this technique no longer makes sense.
For this reason, negative repetitions are better suited to athletes with some experience and very sporadically to those who have recently approached weights.
Eccentric repetition and adaptation response
Outlined the precautions of this intensity technique it is possible to better explain the benefits. The use of negative repetitions finds a wide application both in the field of calisthenics and in the field of body building. The eccentric repetition allows you to perform the movement in the same ROM and with the same force curve as a concentric repetition. This allows you to learn a certain skill in the best way and to reach it in the shortest possible time. For example, if you are unable to master a complete front lever but you are able to maintain a front lever straddle, you can insert a series of full front lever eccentric only in your training. This is possible because the eccentric force is by far the strongest.
In the field of bodybuilding, eccentric repetitions are able to produce the greatest benefits in terms of hypertrophy (and also strength). In this case you have to work on a weight that you are still able to control in concentricity but by performing a greater number of repetitions. For example, if you are able to perform 50 repetitions with a 5 kg barbell curl, you can add another 3 or maximum 5 repetitions only negative once you have reached the concentric yield. The eccentric phase is the most productive in terms of protein synthesis thanks to the high tension it places on the proteins of the muscle fiber. This leads to micro fractures of the fiber which will then have to be rebuilt beyond the previous capabilities. (the mechanism is more complex in reality but it can be summarized in this way).
Another benefit of negative repetitions is to allow you to reduce the length of your training sessions. This aspect is both a consequence of the effectiveness of this technique and a necessity. On the one hand, in fact, it is possible to obtain a greater stimulus of adaptation with fewer repetitions and, secondly, negative repetitions are very effective in taxing the working capacity of both the muscle and the CNS. Finally, a final benefit is given by the strengthening of the tendons and other connective structures of the musculoskeletal system. In fact, hypertrophy should not be limited to just the muscle: weight training also induces an adaptation to tendons and other connective structures.
Eccentric training also subjects these to an important stimulus followed by an equally important adaptation. This must be combined with a mastery of weight: if the weight exceeds your eccentric strength then you cannot even perform eccentric repetitions and if you overdo it you end up having problems. A practical expedient to perform negative repetitions is to perform concentric repetitions of cheating and then follow with a controlled negative phase of 3-5 seconds. Another expedient can be to perform the concentric repetition with the help of both arms or legs, and then perform the negative phase with only one limb.
Example of training scheme
An upper body session using this technique might look like this:
- Incline bench: 4 sets of 4-6 repetitions. In super set with
- Ballasted pull-ups: 4 sets of 4-6 repetitions. 60 seconds rest
- Barbell row: 4 sets of 6-10 reps in super sets with
- Weighted dips: 4 sets of 6-10 repetitions. 60 seconds of rest
- Single hand cable crossover: 2 sets per side of 12-15 reps. Choose a weight that allows you to perform about 5 repetitions. When you reach concentric failure, help yourself with the other hand to perform the concentric phase and then perform the negative phase with only one limb. Perform the negative with a time of 3-5 seconds and reach the maximum ROM.
- Pulldown with arms extended to the cables: 2 sets of 12-15 repetitions. Choose a weight that allows you to perform about 5 concentric repetitions. Then help yourself with the torso to perform the remaining repetitions. 30 seconds of rest
- Cheat curl: 3 sets of 10-12 repetitions. Use a momentum (body moment) to perform the concentric phase and then perform the eccentric phase focusing on the work of the bicep. In super set with
- Pullover in skull crusher: 3 sets of 12-15 repetitions. perform the concentric phase as a pullover repeat. When the weight is close to perpendicular to the ground, perform the eccentric phase but as if it were a skull crusher.