Landrollers, so that's what they call 'em

I know it comes with the territory, but I seriously probably have at least five people a week asking me if I watch the Dog Whisperer on National Geographic. The answer is yes and no. Yes, I've watched the show before, but no, I don't catch it religiously. But every time I do watch the show, there's a dog on a treadmill which always cracks me up or I'm distracted by the roller blades. Cesar, what's up with the wheels? Do we need them that big??

(Apparently, yes, it helps.)