Long-distance running only the placing is of importance. Other less popular variants such as fell running, trail running, mountain running and tower running combine the challenge of distance with a significant incline or change of elevation as part of the course. Multisport races frequently include endurance running. Triathlon, as defined by the International Triathlon Union, may feature running sections ranging from five kilometres (3.1 mi) to the marathon distance (42.195 kilometres, or 26 miles and 385 yards), depending on the race type. The related sport of duathlon is a combination of cycling and distance running. Previous versions of the modern pentathlon incorporated
Marathon swimming Gibraltar between Europe and Africa. Irish swimmer Steve Redmond became the first person to complete the Ocean's seven upon completing the Tsugaru Strait on May 15, 2012. Marathon swimming Marathon swimming is a class of open water swimming defined by long distances (at least 10 kilometers) and traditional rules based in English Channel swimming. Unlike marathon foot-races which have a specifically defined distance, "marathon swims" vary in distance. However, one commonly used minimum definition is 10 kilometers, the distance of the marathon swimming event at the Olympic Games. As in all open water swimming, tides, surface currents and wind-chop are