why is stretching slightly painful and why is that good for us?
In: Biology
Stretching is slightly painful because you are doing things outside of your comfort zone. Like the first day of a new school, or learning to read or trying new vegetables. As you practice, it will get more comfortable just like anything you practice. Like the monkey bars when your hands blistered, but they don’t anymore.
It’s good for us because as we get older we get stiffer and old tight people can loose the ability to run and jump and play.
A lot of things can cause your muscle to tighten with time. A lot of our movement consists of stretching of a muscle, then contraction against a force. For example, think about doing bicep curls – as you let the weight down, you are stretching your bicep as in maintains tension against the weight to allow for a slow descent. As you curl the weight back up towards yourself, it contracts and shortens.
Injury often happens when your muscle is stretched and you try to contract against a weight that is too heavy. If a muscle is already tight, the increase tension and stretch makes a muscle or tendon tear more likely. Your body has special sensors within muscle that communicates to your brain how stretched a muscle is, and if you are really pushing it (pain) to try and prevent you from causing a tear.
When you stretch, you are essentially stretching the muscle and removing the tightness slowly without a weight bearing down on it. Your body still is wary of you over-stretching the muscle – these sensors simply sense muscle stretch, not how much weight is being held. So you really are not doing any damage. Instead, as you stretch the muscle, it slowly removes the tightness, allowing better range of motion while reducing the chance of a muscle tear during contraction (if done correctly).
My curiosity is how do you stretch when normal stretches do nothing? I have a decent amount of hypermobility especially in shoulders and hips and most normal stretching doesn’t feel like it does… anything but I still get tense muscles and can’t figure out how to properly stretch them since standard ones don’t work.
Physical therapist here.
Whether or not stretching is in fact good for us is actually a pretty complicated topic and not easily explained in ELI5 fashion.
Pain is also a super complex topic as it involves mechanical and neural inputs filtered through each individuals own personal experience, habits and trauma. Again, somewhat difficult to ELI5.
That said, pain at it’s most basic level is threat. Things hurt when our nervous system decides something is threatening. The thing is, these sensors aren’t always calibrated well due to our own experiences with things or lack thereof.
Have you ever been outside when its really cold and then come in and put your hands under warm water but it felt hot? That’s an example of the “calibration.”
Stretching, particularly when we are not used to it, is painful because we are putting our body in positions that make it feel threatened. As we stretch more and our body gets used to feeling these positions the threat lessens and we are able to stretch further.
Given that pain is based on threat its worth pointing out that extremely painful stretching is likely counterproductive because you aren’t giving your nervous system enough “space” to learn this position isn’t threatening. You’re making it very, very threatening. A strong but comfortable stretch is almost always more effective at improving tolerance than an overly painful one.
Again, what’s happening in your muscles and nervous system when stretching is way more complex than described here and it’s different depending on how the stretch is achieved (loaded, ballistic, static, passive, active etc.) but the paragraph above about pain as threat and stretching as getting used to threat and therefore feeling less pain is about as ELI5 as it’s going to get.
Stretching doesn’t hurt, but tearing your connective tissues does (overdoing it). Most people don’t understand the complicated thermal dynamics involved in “warming up”; the connective fascia literally binds water to itself in order to radiate heat away more effectively from where the piezoelectric collagen is stressed and resisting. When your tissues are cold, they cannot support as much load without straining and breaking. If you stretch and it hurts, that means things are breaking. If you warm up first, the forces through the connective mesh are distributed well and nothing breaks and nothing hurts until the end of the safe range of motion.
For a more thorough explanation, just ask.
Tl; dr: it hurts when you hurt you and stretching doesn’t hurt. Get warmer first.
Amateur anatomy and physiology enthusiast here: When you stretch (and work out) it essentially damages muscles and bones, but only very slightly. Something called osteoclasts and osteoblasts destroy and rebuild bone respectively while muscles likewise are damaged slightly and healed, but they rebuild stronger than before they were damaged. There are also specialized muscles designed to keep us from stretching too far that tense up as we stretch, but the more often we stretch the more relaxed they will “learn” to be, unless we stretch too much at once in which case they can be even more tense next time reducing flexibility (which is why it is important not to force a stretch and instead build flexibility overtime).
Edit: since this got a ton of attention, if you all are interested in increasing your knowledge on this topic check out Crash Course Anatomy & Physiology on YouTube to learn more. Before checking out that course it is recommended to first check out Crash Course Chemistry and then Crash Course Biology to better understand the lessons. It is easy enough to listen to them while doing other things in my experience.
Edit 2: /u/nivashka below stated
Piggybacking on this comment to add one caveat: If you are bendy or “double-jointed”, aka hypermobile please stretch with care. Flexibility is something gained through repeated stretching and training. Hypermobility is a genetic variation (it can be related to serious medical conditions, but being hypermobile alone is not considered a serious medical condition – however hypermobile people are higher risk for partial/total dislocations during exercise/stretching) – so your range of motion is typically greater (some people have only small joint hypermobility ie. fingers and toes, some have large joints ie. knees/hips/shoulders, some have both) and your body will *not* always send pain signals to tell you to stop. Repeated stretching with hypermobility can often lead to degeneration, chronic pain, etc because hypermobile people are not always aware they should limit their range. Always practice safe exercising and stretching!
Source: I have Ehlers-Danlos and I have dislocated my jaw eating due to hypermobility…more than once.
I thought you meant stretching like in the morning and was like “No mate, that’s not supposed to hurt.”
as far as I’m aware there is very little scientific evidence out there supporting the popularly held belief that stretching is ‘good for us’
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