The best part, in my experience, is that wheelskates are so much more fun than bicycles. After two or three hours on wheelskates I don’t want to stop because I am having so much fun. It feels so free and there are so many skills to learn and master. After one or two hours on a bike, my seat and hands are sore and I’m trying to think of ways to get comfortable. I have always found jogging to be great aerobic exercise but I have never got to a level where I found it to be fun. The same goes for swimming... I enjoy swimming, it is great exercise (particularly in the heat), it is always an effort and a challenge, but I have never really found it to be fun. From my experience, I find an hour or two skating is not only better aerobic exercise than cycling but it also exercises more muscle groups such as lower back, abdominal, even neck & shoulder and requires more coordination skills. I expect and hour or two of jogging or swimming may be better aerobically, although the skating would exert far less impact stress on your joints than jogging.