I guess if you engage in an athletic activity, and that's a real broad definition since curling is considered an Olympic sport, then you're an athlete. Some are just more athletic than others.

I do agree with the post above about advancement but its a personal thing. I have to advance and when I run, I run a training program even if there's not a race coming up. Now that I ride more, I ride for fun and I also have to ride for training. Hmmmm, that brings up another thought. Do you have to compete to be an athlete?