Isometric exercises (flexing the muscle without flexing the joint) are a great way to burn off low level excess adrenaline & stress chemicals, without increasing your heart rate like you would with regular exercise. Not just double duty (burning off chems, while not increasing heart rate if you're close to an anxiety attack), but triple duty because the act of relaxing them after tensing them is a kind of forced relaxation, which makes you more relaxed than before you flexed & held it.
It's a highly useful thing.
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Same Token (or) Conversely... The face flexing? Any chance that's a baring your teeth kind of "smile"? If so... That particular expression dumps chemicals into your bloodstream. I use it when running (because I don't get a second wind until late), or any time I'm tired and need a bit of a natural "up". Fight chemicals; adrenaline + endorphins + a few others.
Highly useful if you need to "get your fight up" (anger usually overrides fear) or for short term pain relief... Problematic if you're trying to lower the fight-response.
People are "weird" mammal-speaking... Because we smile when happy. But bearing your teeth? Not a true smile, but a kind of snarly I-wanna-bite-someone way, will trigger that neurochemical response. Like people hooked into certain kinds of brain scans will show sudden flooding of neurotransmitters / brain lights up like a Christmas tree in specific areas with the bite-someone-bared-teeth, but a real smile shows entirely different neurochem.
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If, otoh, it's a lip curl? Or half your face going one way? That's disgust. No idea what that does chemically (if anything). But it's a good "tell" (just like pressing on one eyebrow is a good tell for shame, or whites above the iris of your eyes for fear) that you can work with if you're having difficulty connecting with your emotions, and can even be played around with. Glaring (both eyebrows drawn in) & and the anger that prompts it can be deliberately relaxed by running your hands over your eyebrows to relax them and pull them up. LOL not by invoking shame. ;) (Touching an eyebrow unconsciously with one hand shows shame. Not touching them on purpose). You see people self-moderating / self-soothing anger and frustration all the time, by pinching the bridge of their nose (pressure point, relaxes forehead musculature) and/or smoothing out their foreheads or eyebrows with their hands.
Reverse engineering emotional response, by changing the expression on your face? Either on purpose with your face, or manually... Is just a damn cool trick. I <3 Science!
