You know, Michael Phelps is from my hometown, Towson, Maryland and no, I don't know him personally. I have seen him around town several times and have been known to swim where he trained, however, we aren't buds.
But I can offer you this: I have competed at pretty high levels on horseback, and not so high levels of downhill skiing, ice skating, shooting, and dance. What I have learned over the years is that it's MUCH easier to compete without an animal! That being said, competition is about learning a skill very, very well. So well, in fact that it becomes automatic. While you are always perfecting your skill, and continually learning more things to make you better, the day always comes when you have to face the crowd and your competitors.
And that is when anxiety comes in. I am sure that you know that anxiety is a good thing, designed to protect us in times of danger. A certain amount of anxiety hones our senses, makes us more aware, as well as being stronger, quicker and focused. Too much anxiety, however, is not a good thing. There is a slope, if you will, when you get better as the anxiety increases, then worse as the anxiety continues to increase.
So, if that's the case, how do you keep your anxiety (while in competition) at a peak level without destroying that chance of winning? Mostly by overtraining. You do the same movement, swim stroke, or dance step, over and over until your mind and body barely have to think about it. Even with horses: you overtrain enough to get the horse comfortable with what you want, without getting the two of you "sour" on it.
How does this translate to us in day-to-day living? Well, if you are prone to anxiety, panic attacks, or being stressed, then you have to learn a few things by rote, or overtraining. Deep breathing is one of the key elements and strongest skill we can learn to manage stress or anxiety. That, and guided imagery.
Yes, I know you've heard this many, many times, but obviously not often enough if you aren't doing it several times a day! That's right, several times each and every day until it becomes second nature.
Oh, yes, I've heard it many so times in my practice, "Gee, Doctor, I'm too busy to practice this breathing thing four minutes, four times a day." Ok, well, if you have seen a one hour TV show, you have seen 24 minutes of commercials. Check it out. Too busy?
Unfortunately, it only says that you're not so anxious that you need to fix it. It's your decision. But if millions of athletes have learned to master their sport, you can learn to master this. It's really not rocket science. Good luck!