Aquathlon Aquathlon is one of the offshoots of the original triathlon. Aquathlon is the combination of running and swimming. Distances may vary, but the standard distances for competition are a 2.5 km run, 10 km swimming and another 2.5 km run. Aquathlon is much seen as a training event for triathlon competition, but there are official championships. Aquathlon is governed by the International Triathlon Union, which was founded in 1989. World Championships: Men Women