Hi Ben.
Love your builds. I have an idea for a video game controller on a treadmill. I was thinking of a display screen attached on top of the treadmill display for a raspberry pi mame machine with control buttons or joysticks that can be use while on the treadmill. Personally I'm into old school games but anything would be a great exercise distraction. The last game console I got was the nes. I don't think I would like the running, shooting, escaping from zombies game (more Mario Brothers). Anyway, just a thought.
Glenn