The best swimmers among female Ironman triathletes complete the swimming portion of the event in 50 minutes to an hour. At the World Championship, the cutoff time for all competitors is two hours, 20 minutes. Any participant who fails to complete the 2.2-mile swim within that time is eliminated from the competition.
Vitamin K: One of two naturally occurring fat-soluble vitamins (vitamin K1 and vitamin K2) needed for the clotting of blood because of an essential role in the production of prothrombin (a clotting factor).
Humans are unable to synthesize vitamin K. It must either be acquired from dietary sources, or as metabolic by-products of intestinal bacteria. Still, the vitamin is so widely distributed in nature that nutritional deficiencies do not occur under normal circumstances.ecause vitamin K is common in many foods and is also synthesized by intestinal bacteria, deficiency in humans is unlikely to occur under normal conditions.