No one has ever won two Olympic titles. Can Alistair Brownlee become the first? One of the best swimmer's in the field, he can dominate on the bike, too. The only question is whether or not his ankle, which was operated on late last year, is ready for the challenge of a super-speedy 10 km run. The 28-year-old has won his last two outings on the ITU circuit, seemingly boding well for a gold-medal defence.