How do you balance the sit-at-desk nature of design work with the need for physical activity in your day-to-day life?  

Personally, I go for walks at lunch, and sometimes I'll do the 4 kilometer walk home.  If I'm lucky, I'll get some tennis in - but there doesn't seem to be a lot of time for that.  I used to take intermittent breaks and do 20 pushups at a time and get back to work.  Of course, not every office space allows for this, and it doesn't really seem appropriate for the workplace in retrospect.  Still, how can I  regret getting that exercise?

If the interface from the Minority Report because a reality soon, we could strap weights to our arms and get a decent upper body workout while working.  That would be awesome.  Maybe we could hook up treadmill-like devices for scrolling up and down.  The point I am trying to make here is this: if we are going to be spending all our time designing, shouldn't we be looking at ways for it to actually *be* incidentally good for us?  With the rise in popularity of gesture-based input systems, I can see benefits arising from some integration with design applications.