When a girl does this, they are trying to justify their own value and make you think that they are a catch. That she is desired and that every man wants to be with her. That you should work harder to and continue to chase her. The reality is that you are the prize now and she should be chasing you.
I had an ex tell me how "muscular" her ex-bf was. So I decided to creep his Facebook page out of boredom and saw a guy who was essentially fat and husky. Their was nothing athletic about the guy at all. She also went on to tell me about another bf who was a "professional" mountain biker, so I looked him up and noticed that he actually sucked and was being beaten by novice weekend warriors.
It's just another tactic by a woman to inflate her own ego. Ignore that BS and focus on you!