ahh ok thanks for this insight (i mean technically flexing ur bicep is a workout but obvisouly if you can even get any gains [i don't think you can] it will be minimal) but now that i know this do you know any actual massaster workouts?
I would consider it an isometric and do it myself as an experiment. But you should be careful as it can lead to teeth damage(especially the protection layer of your teeth) and can cause cracks if done to hard and excessively. If you want the save way just chew hard gum like falim. This may give you TMJ (like clenching) but nothing else if done correctly
