Why not? Do you want a treadmill in front of your desk at work? I mean, as long as it's optional!
I keep 5-pound weights on my desk and use them when I'm reading the computer screen and don't need my hands on the keyboard. And I'm thinking of buying a desk that has a motor that changes the height so it can be a standing desk when I'm in the mood for that. And also this little bouncy, wobbly stool for it.
Computers hypnotize me into sitting frozen in place. I need other inanimate objects to break up this unhealthy relationship.