If there’s one disintegration that has hurt the flexibility world greatly, is that between stretching and movement. Actually, most of the ineffective techniques and lack of progress have their root in this separation, which is why it’s time to directly challenge it.
On what basis? Any part of a movement has various parts. You have a portion in which there is a lengthening of the agonist muscle, and gravity is helping you in the movement. This is the eccentric, as when lowering on a squat. You then have the concentric, in which the agonist is shortening and gravity is opposing the movement. This would be the raising part of a chin up. Finally, you can have an isometric at any part of the movement, in which the increased tension does not correspond with a change in muscle length, like holding a tuck planche position.
Now, where would stretching lie? Even though all stages can build strength, what a strengthening exercise emphasizes is the concentric part. In this one, you are fighting gravity and thus getting stronger.
On its part, a stretch it’s all about the eccentric portion of a movement and, as strength training, can also use isometrics.
For example, if you are doing a Pec fly, you will get the strength benefits mainly on the way up. If you just prolonged the lowering portion, you could get a stretch, not only with this exercise, but with any exercise in which there is movement.
Now, some people will oppose to this idea on the basis that, while on strength training there is tension, in stretching there is relaxation. This is based on the idea of reciprocal inhibition, the concept by which the contraction of the agonist (ie. Biceps) is accompanied by the relaxation of the antagonist (ie. triceps), in order to not hinder the movement.
The problem with this view is that it confuses lengthening with relaxation. In the case of the biceps curl, what analysis of muscle activity shows is that the triceps is not suddenly turned off, but that it maintains an eccentric contraction. That is, it stretches. Even more, the stretched muscle actually increases it’s electrical activity. Reciprocal inhibition has been generalized when it fact is just a reflex for very specific scenarios. At least during waked states, nothing in the body ever truly gets relaxed, because if that was the case, our skeleton would just fall to the ground.
In other words, any action causes a reaction, but contraction is not necessarily the opposite of relaxation. Whenever there is movement (even in isometrics), there is contraction, whether that is a concentric or an eccentric one. It is more a matter of the stretching technique being used, as passive stretches try to isolate the relaxation aspect of stretching, and loaded stretches try to create tension in the end range of motion. Either way, as long as there is gravity, every stretch will be under some kind of load, and thus involve some degree of contraction.
The implications of this are bigger than one can imagine. To give you some ideas, it means that:
- Flexibility and strength are not so different. For example, Kit Laughlin developed this technique called Pre-exhaustion, in which you do stretch, a strength exercise for the same muscle group, and then a long stretch. Guess who talks about something similar? Charles Poliquin. In The poliquin principles he talks about a technique by the same name, in which you can superset an isolation exercise (e.g. triceps extension) with an integrated one (e.g. dips), or do it the other way around, just to increase the overall stimulus. Try applying any strength technique that you know of (clusters, grease the groove, periodization, supercompensation, deloads, pyramids, etc) to your stretching, and tell me if it doesn’t produces results.
- It also means that the same qualities that can affect any movement, as strength, control, muscle memory and coordination, will be relevant for stretching. That is why loaded stretching can be so effective, because it recognizes that strength and flexibility should not be separated. It also means that any stretching position is a skill, and as such requires time and repetition to be bettered.
- That is why, also, passive stretching must be taken with a pinch of salt. While it does have great benefits in the psychological realm and for specific scenarios (like postural corrections), when it comes to really increasing your range of motion, contraction must be present. What gets you more flexible is getting comfortable in the end range of motion, not as a mental trick, but as a deep confidence that comes from strength, practice and control in that position.
- In other words, stop creating categorical statements as “to get flexible, you must relax or contract”, as in reality it is the alternation between contraction and relaxation that produces the best results.
- If stretching is just spending time in the eccentric, any movement can potentially be a stretch. You can just sink into the lowest part of a dip, a squat, a chin up or a press handstand, and let gravity do it’s job. This is also why training with your whole range of motion can be so beneficial for your flexibility, and why not doing it will create an immobile body.
- For movement, flexibility is just as important as strength. Without one, the other losses its purpose.
- So, if stretching is part of movement, does it builds muscle? Well, but some research has suggested that getting stronger in a stretched position can contribute to hyperplasia, more than hypertrophy. While hypertrophy is the increase in size of existing muscle cells/fibers, hyperplasia is an increase in the existing number of muscle cells/fibers. There is actually whole training methodologies devoted to this, like Doggcrapp. Whether that’s true or not is yet to be seen, but people like Arnold and Jujimufu do suggest letting the muscle stretch for bigger gains.
- Finally, the division between mobility and flexibility is relevant in the current context of separation. While flexibility is range of motion without strength, mobility includes strength and control. This concepts might seem artificial but, in a world full of people who think stretching is just trying to relax while grabbing their toes, it does have a place.
In a few words, the unitary concept between strength and flexibility is movement. Let that reality sink into your mind, and transform everything in your flexibility training.
If you’d like to know more about these topics, I recommend the work of Emmet Louis and Andreo Spina
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