Extreme Marathons
Hugh Gentry / Reuters
Ironman Triathlon World Championship, Kailua-Kona, Hawaii
This classic test of stamina combines three endurance events a 2.4-mile ocean swim, a 112-mile bike ride across the Hawaiian lava desert, and a 26.2-mile marathon along the coast of the Big Island. The current course record is 8 hours 4 minutes and 8 seconds.
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