Why do we stretch?

Humans stretch, mostly with our arms and upper bodies, often accompanied by a yawn. My cats stretch with their entire bodies. Other animals stretch as well.

Why does it feel so good, and physiologically, what does it accomplish? It seems to be similar to the effects of a massage.

It stretches… your muscles? You’re carrying around 75 pounds of tissue fibers that have been honed by millions of years of evolution to keep you moving quickly and efficiently until you can have successful offspring. You sit at a computer for four hours and you’re disrespecting your ancestors back to before they were vertebrates.

It increases longevity…

I finally thought of one…

Well, muscles can’t stretch themselves. They can only contract. If a muscle isn’t stretched out, then it can’t really do anything.

So when you stretch out a muscle, (which usually requires contracting another,) then you’re getting it ready for action.

That’s all I’ve got so far.

I don’t have a cite for this but I always heard that our veins have very low blood pressure compared to our arteries so when when we are at rest for a period of time we stretch to squeeze the veins into pumping blood. I also heard that in our veins there are one way valves so no matter which muscles squeeze which veins the flow is always in one direction.

I was just thinking of making a thread about this myself! I’ve often wondered (usually after a stretch) what the exact signal that you need to stretch is, because I can never remember what kind of sensation it was that triggered the stretch in me. And then, why can’t you repeat the stretch in an equally satisfying way right after the first stretch? Simply tensing your muscles tightly just doesn’t cut it.

I stretch with my whole body – legs and feet tense, too, and if I’m standing up when I do it, I’ll fall over afterwards. Also, while I’ve heard it said dozens of times that the closest analogue to an orgasm is a sneeze, I’ve always felt it is the big yawn-and-stretch. Both involve full-body contractions that leave you, well, limp afterwards. (Plus, sneezing doesn’t feel a damn thing like having an orgasm, and is annoying to boot.)