A competitor participates in the 2013 Spartan Race obstacle racing challenge in North Vancouver, Canada, June 1, 2013. Spartan Race consists of the Spartan Sprint (3 miles of obstacle racing), trail races, mud runs, tough mudder runs, warrior dash, spear throwing, wall climbing and American Gladiators. (Xinhua/Sergei Bachlakov)

Competitors participate in the 2013 Spartan Race obstacle racing challenge in North Vancouver, Canada, June 1, 2013. Spartan Race consists of the Spartan Sprint (3 miles of obstacle racing), trail races, mud runs, tough mudder runs, warrior dash, spear throwing, wall climbing and American Gladiators. (Xinhua/Sergei Bachlakov)

Competitors participate in the 2013 Spartan Race obstacle racing challenge in North Vancouver, Canada, June 1, 2013. Spartan Race consists of the Spartan Sprint (3 miles of obstacle racing), trail races, mud runs, tough mudder runs, warrior dash, spear throwing, wall climbing and American Gladiators. (Xinhua/Sergei Bachlakov)

A competitor participates in the 2013 Spartan Race obstacle racing challenge in North Vancouver, Canada, June 1, 2013. Spartan Race consists of the Spartan Sprint (3 miles of obstacle racing), trail races, mud runs, tough mudder runs, warrior dash, spear throwing, wall climbing and American Gladiators. (Xinhua/Sergei Bachlakov)

Competitors participate in the 2013 Spartan Race obstacle racing challenge in North Vancouver, Canada, June 1, 2013. Spartan Race consists of the Spartan Sprint (3 miles of obstacle racing), trail races, mud runs, tough mudder runs, warrior dash, spear throwing, wall climbing and American Gladiators. (Xinhua/Sergei Bachlakov)

Competitors pose during the 2013 Spartan Race obstacle racing challenge in North Vancouver, Canada, June 1, 2013. Spartan Race consists of the Spartan Sprint (3 miles of obstacle racing), trail races, mud runs, tough mudder runs, warrior dash, spear throwing, wall climbing and American Gladiators. (Xinhua/Sergei Bachlakov)