Behold! Make sure your treadmill is in the same room as your TV!
In fact, I'm certain that's the only reason I run in the winter. Because our projector broke this week, and watching the wall when I run has been pretty horrendously boring.
In the warmer seasons, I run with my wife outside. That is the only reason I run outside. I wouldn't do it alone. I'd prefer my basement. After all, there's a TV there.
From a biological standpoint, we were designed to be boar hunters. Now that we have to fake it, it's harder.