[Arch0wl]

You wouldn't notice the gains really even if someone did since it'd be in very specific muscle regions that don't hypertrophy much.

Games like Stepmania involve muscular endurance, but training for power/explosiveness would probably involve forearm training to a great degree. And if you're going to train forearms you might as well just train your whole body and get jacked in the process.

But yeah, the B to A area of play is the best for increasing skill. The C to B area means you're not truly hitting the patterns as they are on the screen and are probably bullshitting somewhat, so your movements don't represent what is required and you probably won't be strengthening the muscles used in those movements. Playing for AAAs is actually extremely counterproductive to getting better (being able to pass harder songs) although it may help timing. Once you can AA or even borderline AA a song, you should move on to something else.