Earlier quoted context omitted.
Consider StarCraft: Brood War, a legendary real-time strategy game. To be played well, it requires between 200-400 actions per minute (APM), with some players going even beyond 500 APM. Some games last for more than an hour. Players use both the mouse and the keyboard. There's always more to do than you can realistically do. You are always putting out fires, managing your economy, producing units, securing income, ca…
Let's be honest, most of those actions are useless keybashing and clicking. It's easy to get a high APM.
Anyways, I think you are missing the point that this thread is about active sitting. I imagine there isn't much difference to the meaning behind movement: movement is movement, meaningful or not.