One of the many great points she makes is that when men are asked about their success, they generally attribute it to themselves, as in, "Yes, it's true, I'm great." Women, on the other hand, are more apt to attribute their success to luck (huh?) or to help they received from others or others with whom they collaborated. In other words, women are saying, "Yes, but..." about their success.
I'm all for collaboration. In fact, I think it's something we need a lot more of in the world. And I certainly think that giving credit to others where credit is due is vital. Yes, but--as women are prone to say, and so I'll say it, too--we also need to learn to take credit. Sharing success around is a different thing from disowning the success itself. The latter is what women have too much of a tendency toward. Because it turns out that when we own our success, we actually have more; and when we don't take ownership of our success, when we are too busy giving the success away, then we risk bankrupting ourselves along the way. (Success is not like that old singsong about love--something if you give it away you end up having more, and so on.) Succeed. Embrace that success. Succeed more. That's the upward spiral cycle we want to hitch our star to.
Sports is a good place to practice, because when you run that PR, or cycle up that mountain, or ski down it, for that matter, there's no one else you can attribute that success to, really. Yes, coaches help and so on, but in the end, it's you who did it. The truth is inescapable--you'll just have to think to yourself at some point, "I am fabulous."
Try it some time!