An Ironman 70.3, also known as a Half Ironman, is one of a series of long-distance triathlon races organized by the World Triathlon Corporation (WTC). The "70.3" refers to the total distance in miles (113.0 km) covered in the race, consisting of a swim, a bike ride, and a run. Each distance of the swim, bike, and run segments is half the distance of that segment in an Ironman Triathlon. The Ironman 70.3 series culminates each year with a World Championship competition, for which competitors qualify during the 70.3 series in the 12 months prior to the championship race. In addition to the World Championship race, Ironman 70.3 championship competitions are also held for the European, Asia-Pacific, and Latin America regions. The time needed by an athlete to complete a 70.3 distance event varies from race to race and can be influenced by external factors. These factors include the terrain and the total elevation gained and lost on the course, weather conditions, and course conditions. Finish times range from sub-four-hour completion times by elite level athletes to the imposed race cut off, which is commonly 8 hours and 30 minutes after the start time. Ironman 70.3 World Championship Qualification into the Ironman 70.3 World Championship can be obtained through the Ironman 70.3 series of events held during the 12-month qualification period prior to the championship. Some Ironman 70.3 events also act as qualifiers for the full Ironman World Championship in Hawaii, USA. Professional triathletes qualify for the championship race by competing in races during the qualifying period, earning points towards their pro rankings. An athlete's five highest-scoring races are counted toward their pro rankings. The top 50 males and top 35 females in the pro rankings qualify for the championship race. Amateur triathletes can qualify for the championship race by earning a qualifying slot at one of the qualifying events. At qualifying events, slots are allocated to each age group category, male and female, with the number of slots given out based on that category's proportional representation of the overall field. Each age group category is tentatively allocated one qualifying spot in each qualifying event. From its first year as a championship race series in 2006 until 2010, the Ironman 70.3 World Championships were held in Clearwater, Florida, USA during the month of November. In 2011, the 70.3 Championship venue changed to Las Vegas along with date of the event