How fast do I need to run to charge my phone?
What happens if I trip and fall inside the wheel?
Some guy built a hamster wheel desk, but I do not see the advantage over a treadmill. I have one in my room which would be perfect for the barely-measurable pace that he was going.
The tread is a little loose and randomly slipped when I tried running on it.
This guy's version looks pretty good:
I watched a few other builds and they looked atrocious.