COEUR D'ALENE, Idaho -- Ironman 2013 begun at 6 a.m. Sunday.
The triathlon includes a 2.4 mile swim in Lake Coeur d'Alene, then a 112 mile bike ride then a 26.2 mile run along the shore of the lake.
The water is expected to be between 55 and 65 degrees.
The first 50 people to finish the triathlon qualify for the Ironman World Championship in Kailua-Kon, Hawaii.
For live twitter updates: click here