If you haven’t already heard, studies show that sitting for long periods of time isn’t healthy. This doesn’t mean you have to give up on your computer time. Get a treadmill desk!!
This guy has a video that shows you how to build your own treadmill desk.
Does it look too difficult? You could buy a treadmill desk as well;
There’s also the option to use a balance ball chair, which offers your body more effort to balance than just sit still for long periods of time.