noun - Beluga is a slang term describing an athlete in the open water swimming community who weights 200 pounds (90.7 kilograms) or more. Its equivalent in the triathlon and road running worlds is referred to as a Clydesdale who competes in the Clydesdale division.
The female equivalent in the triathlon and road running communities is either a Filly or Athena. The International Triathlon Union (ITU) Technical Commission states that a Filly athlete must be at least 150 lbs. or 68 kg. Most races advertise the weight requirement for Fillies divisions on the race registration information. The Athena division, commonly called the Filly division, in running is for female runners who are over a certain weight which is not standardized. In some races, the minimum weight for an Athena division runner is 140 lbs. or 63.5 kg; other races require Athenas to be at least 150 lbs.
That beluga has incredible endurance, but he really excels at ice swimming.
The slang term beluga used for homo sapiens is different than the beluga whale, a marine mammal. The beluga whale or white whale is an Arctic and sub-Arctic cetacean. It is one of two members of the family Monodontidae, along with the narwhal, and the only member of the genus Delphinapterus. It is commonly referred to simply as the beluga or sea canary due to its high-pitched twitter.
Usage dating to the 1990's from Travis England in Seal Beach, California.