I actually don't find Skylink to be faster - forget the exercise benefit. I can get from C39 to D10 or so in around 15 minutes. Skylink is not really quicker than that IMO.

The only hazard of walking is the never ending parade of "excuse the cart" - ironically sponsored by McDonalds - filled with 10% people who need them and 90% fatties who - more than anyone - should be walking. I also find the drivers' tone that it's somehow inappropriate for pedestrians to assume right of way in a flippin' airport offensive.

But, of course, I digress...