Ironman competitor Timothy O'Donnell earned fifth place at the Ironman World Championship last October in Kailua-Kona, Hawaii. As he's currently training to return to Hawaii for the October 11 Championship, O'Donnell took a break to offer some tips on how he handles the heat, wind, and humidity of the island and withstands the added pressure of the biggest race of the year. "There is a rule of thumb in Triathlon," O'Donnell says. "Never use anything during a race that you haven't used in training." Here he offers an exclusive breakdown of his gear.