A race is a contest of speed.[1] Racing as a competitive activity has taken numerous forms throughout history, both formally and informally. The simplest form of a race is two or more people running on a track with a set distance. In modern competition, the distances run commonly range from 100 metres to the "marathon", with a length of 42.195 km (26 miles 385 yards), though ultra-marathons of much greater distances also occur.
People have also raced using most forms of locomotion. There have been race events for horses, horse-drawn chariots, dog-sleds, people swimming, on skis and bicycles, and all manner of boats, motor cars of various categories and aircraft. Some races place artificial obstacles to make the race not purely a contest of speed; these include hurdles events, and equestrian steeplechase events.
There are events that combine different modes, including triathlons combining swimming, running, and bicycling, and events that combine a race with other athletic competitions, such as the Olympic biathlon, modern pentathlon, and decathlon. There have also been novelty events such as the great, but impoverished Olympic sprinter Jesse Owens racing against a horse. The word "race" is also used to describe more abstract races, such as a "home run race" between two batters having exceptionally good seasons (such as Sammy Sosa and Mark McGuire in 1998).