If you can swim, bike, and run, then you can compete in a triathlon. This past weekend the Ironman World Championship event was held in Kona, Hawaii, where the sport's top athletes had to swim 2.4 miles, bike 112 miles, and run a full marathon in less that 17 hours. It was the 35th anniversary for the event, which started when a group of athletes wanted to determine who was the fittest in the three disciplines. Triathlons are now held all over the world at various distances, and today's post looks at a few of them since the start of the year. -- Lloyd Young ( 34 photos )

Amateur triathletes start the 2.4 mile swim portion during the Ironman World Championship in Kailua-Kona, Hawaii, on Oct. 12. (Hugh Gentry/Reuters)