Barbara Riveros Diaz, Chile. Age at the Olympics: 24
Barbara Riveros Diaz burst onto the scene in 2010, when she came out of nowhere to win the Sydney leg of the World Triathlon Series and then placed second a few weeks later in Seoul. In 2011 she won the ITU sprint world title, placed second in Sydney, won the Ishigaki World Cup, and earned silver at the Pan American Games. Riveros’ superb sprinting speed will play into her favor as she heads into London, but she does often miss the first swim pack, which could put her out of medal contention if the sport’s swim-bikers decide to press at the front. It’s also unknown how Riveros will fare now that she has left her coach, Darren Smith.