The Wall Street Journal explains how a scavenger hunt ruined Kikkan Randall's chance at an medal in the 2014 Sochi Olympics. Randall, who was the favorite to win the Freestyle Sprint race, failed to even make it out of the quarterfinals.
The article, Kikkan Randall: An Olympic Mystery: How the U.S.’s Cross-Country Medal Hopeful Failed to Even Come Close, explains that Kikkan ditched a two-hour training session in December for a three and a half hour birthday-present scavenger hunt. Exhausted and stressed, she threw out her back the next morning. The few days of rest caused her body to peak in January...well before the Olympics and her planned peak.
The article also goes into her plan for the next Olympics: train like mad to become a better classic sprint skier, since 2018 Pyeongchang Olympics will have a classic sprint rather than the freestyle sprint. (Randall is a freestyle sprint specialist).