 Well, I'll go first with gymnastics because I think that's where one of the U.S. most dominant athletes is, and that is Simone Biles. Of course, she's already at this point in her career the most decorated gymnast of all time. She has seven Olympic medals on her record already, and she's 27 years old. That's a stage by which most gymnasts' careers are long over, but she is looking as dominant as ever.