I am using a twelve-day guest membership at the Y. I keep it simple, walking on the treadmill at a severe incline. I have never watched sports on the wall TV while walking on the treadmill. I find I have to hold the railings, because I lean in to the action on the screen. If the running back cuts left, I mimic this. Even when I tell myself not to, it merely decreases the effect, not eliminates it.
I recall from video games that I would do something similar. Playing Pac-Man would would make me tense and wear out not only my wrist, not only my arm, but my whole upper body. There are those who can stand immobile and gently move controls, but I suspect most people move sympathetically with the action, at least a bit. I have no doubt that I am well worse than average on this scale. It feels hard-wired. I do something like this in action movies as well, and even some whivh are not action movies. I am far too part of what happens on the screen, like the rabbits in Watership Down when listening to a storyteller. I duck, I wince, I laugh and respond much more loudly than others. If a screen is happening, I have to pay attention to it. If songs with lyrics are playing I cannot keep it in the background, I cannot ignore it. Ditto the radio in another room, if the words are discernible. Only in the presence of a more powerful distraction can I not attend.
I suspect it is more like what our ancestors did - our remoter, more primitive ancestors.
It is a possible explanation why I mistrust movies. I view them as too powerful for our neurology. Mine anyway.