Does stretching really increase our flexibility?
What is happening when we stretch?
When a muscle is taken into a stretch the proprioceptors (nerve endings that relay information to the nervous system) are sending a message to the brain telling our muscle to contract to resist the stretch. This is what we call the stretch reflex. We are programmed this way to prevent our muscles to overstretch and get injured. But then a question arises: if when we stretch a muscle, it contracts, then why is it said that stretching will increase the length of our muscles?
Overruling the protective reflex?
Well some studies have shown that after the protective stretch reflex has happened, the proprioceptors will send another message: it is ok to lengthen now. Yet do we really want to stop or even just reduce this protective stretch reflex, since this reflex it the one that will protect us from muscle and tendon tears? Of course we don’t want to overrule this reflex, as it will not be safe for us. But then the question remains: why do we stretch?
Time will tell:
When we stretch our muscles are contracting against the stretch to protect but if we hold it long enough (at least 30 seconds) the proprioceptors will adapt to this new position and the cells inside the muscles will reorganized and a different set of information will be sent to our brain. However this will not happen after a single stretch. The stretch needs to be repeated over some time before anything changes.
When is too much too much?
Yet it is also very important to note here that the stretch should not be too intense either. If the stretch is too intense, the brain will automatically put the emergency brake on and in order to protect the joints and muscles it will send a message to the muscle cells to contract. For our muscles to lengthen the brain needs to know that it is safe to do so. So in reality when we take our muscles into a stretch it is very important that we stop before it is too much. We should feel the stretch but it should not hurt. Then we can hold that stretch for at least 30 seconds.
Will my muscles length increase?
This stretch will not make a massive difference to the length of the muscle straight away. Nor do we want it to make a massive difference, otherwise this means that we would have overruled our protective mechanism. Studies have shown that a gentle stretch repeated frequently will increase our flexibility over time. So our range of motion will be greater without the brain putting the emergency break on. But this needs to happen slowly. Our brains really rule the show when it comes to range of motion or flexibility.