Running: A Fever

I've been looking for alternatives for cardio, since I don't care much for running or stationary biking. One suggestion I received was skating. There are several types of skating, including recreational, competitive speed skating, and the kind I'm interested in, fitness skating. Obviously, I needed a pair of skates, and I chose the Rollerblade Bladerunner. Rollerblade is one of the largest manufacturers of inline skates, in fact the brand name used to be synonymous with inline skating, the way escalator is for moving stairways. Since they are so big, they have a full selection of skates from child to adult, from beginner to pro, and all of the different styles for speed skating, fitness skating, and others. But I chose the brand mainly through the Amazon ratings. I chose an intermediate style of skate. I have a lot of experience skating, but have not skated for a long time. These skates have 90mm wheels, which are in between the standard 80mm and what the speed skaters use, 100mm or even 125mm. The speed skat