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  • Trainer Maxim

Flexibility. Not your muscles to blame!

Good day comrades! Today I want to talk about flexibility which is a very important aspect of our health. It keeps us away from stiffness, injuries (most of the time) and limited range of motion. Everyone wants to be more flexible…I think. When we see somebody performing an impressive split or folding their body in half we would say: “Oh wow I wish my muscles were that flexible!”. Is it really your muscles to blame?

Let’s have a closer look at how flexibility happens in an “apparently healthy individual”. By this I mean a person who is relatively healthy and relatively free from joint complications caused by arthritis or any other conditions of the kind.

I am going to talk about our Central Nervous System (CNS), which consist of the brain (small, 2.5 - 3-pound thing inside our skull) and spinal cord (the big long thing in our backbone which bears all of our life’s ordeals)

It is the CNS which is responsible for the functionality of our muscles including flexibility. Flexibility is, simply, an ability of a muscle to be elongated by outer force/impact or by opposite muscles contraction. A muscle itself cannot elongate on its own. It can only shorten (flex) on its own (kinda on its own…again, it is the brain). The muscles cannot push, they only pull. Even when you are pushing a door, in reality, your muscles are pulling. I know, weird.

The CNS is responsible for the functionality of our muscles including flexibility

Your muscles structurally are no different than ones of a professional gymnast and capable of being stretched as much as that gymnast's muscles even right now with no special training. Though you cannot go into those "crazy" stretches. Why?

Your muscles structurally are no different than ones of a professional gymnast

Inside the muscles, we have receptors called "muscle spindles". Those receptors are simple “naked” nerves like ones which cause a toothache and are woven around the muscles filaments. When a muscle is being stretched, the receptors are being squeezed by the muscle tissue sending the signals to the CNS reporting severity of an impact. The more we stretch the more impact the receptors endure and report. That is how the brain knows how much the muscle is being elongated from its resting length. 

Meanwhile, the CNS has a certain limit, called a threshold of impact on the "muscle spindles". That threshold of impact has been formed based on your previous life experience. For example, you sit all days and barely move your legs to do anything other than walking. So your hamstrings are stretched only that much. After years of this lifestyle, your Brain starts “thinking” that that little amount of stretch is the maximum acceptable amount of impact on your hamstrings’ "muscle spindles". Because your hamstrings simply have never been stretched beyond that point. It is logical for the Brain to assume that this is it, this is our max. Basta!

The CNS has a certain limit. Basta!

Let’s say the current threshold of impact is 50 points (whatever those points are). As long as the sensors report the impact under 50 the CNS takes no actions, yet as soon as it’s over 50 the CNS triggers a reflex known as the “stretch reflex” (myotatic reflex….myotatic ??? it sounds sophisticated on purpose so that you have to spend years in university memorizing it and PAYING for it….capitalists! )

 The “stretch reflex” is an act of a sudden muscle contraction (aka cramp) in response to stretching designed to bring a stretched muscle within the "safe" range of its length to prevent a potential damage to the muscle itself and its tendons (things connecting the muscle to the bone). In our case that "safe" range is defined by the current threshold of impact and it is everything under 50. Can your hamstrings be structurally stretched more - absolutely! Will the CNS allow it - NO!

Can your hamstrings be structurally stretched more - absolutely! Will the CNS allow it - NO!

How to fix it. Super easy. Trick the brain. Put the hamstrings in a gentle stretch which is perceived by you at 3-4 out of 10 where 1 is super “nothing” stretch and 10 "get me out of there cannot breathe". That would correspond to 40-45 points of impact on the hamstrings’ "muscle spindles” (those naked nerves) thus no stretch reflex will be triggered as the current threshold is 50 points. Hold the stretch for a while, breathe normally and relax.

How to fix it. Super easy. Trick the brain.

As the CNS sees no structural damage to the muscles and the general state of the body is relaxation then after a couple of stretches, the CNS will rewrite the threshold to the new number 5-10% greater than the original one. Now with the new 55-60 point threshold of impact on your hamstrings’ "muscle spindles”, we can increase the hamstrings’ length up to the greater extent without a risk of triggering the "stretch reflex” (cramps).

CNS will rewrite the threshold to the new number

Repeat this algorithm consistently to keep increasing the threshold and flexibility will be improved significantly in no time. Did the muscles themselves structurally change? No. They are the same. What changed is the information stored in the Brain and its response to a stretch. The phenomena are known as Neuroplasticity. 

The phenomena are known as Neuroplasticity. 

I would recommend that you do 1-2 stretching sessions a week, 30-40 minutes each. Choose 1-3 stretches you like and perform 3-4 sets of 30-60 second hold for each. Give it 3-4 months and you will be surprised by the progress. 

VERY IMPORTANT! if you stretch a muscle too much, meaning that you perceive a stretch at 7-9 out of 10 then there will be little to no progress. It is because the perception of pain will most likely trigger another reflex you must have heard of - “Flight or Fight”. When it happens the body goes into a survival mode, the blood vessel constricting due to an elevated production of hormone “adrenalin” thereby increasing the heart rate and the blood pressure. Your breathing pattern becomes intermittent and fast to supply more oxygen. Under this circumstances, the Brain will “learn” NOTHING. If any it will decrease the threshold of impact on your hamstrings’ "muscle spindles” to prepare them better for potential fast running. We are in survival mode in the end.

Don’t stretch muscles too much!

VERY IMPORTANT! At the very begging of your journey to increase flexible AVOID stretching every day! Why? I will tell you in my next article.

Don’t stretch muscles too often!

That is it. I hope you enjoyed the article. If so please leave your comment or questions in the comments section. Stay tuned and thank you for reading that far!

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