Biathlon is any sporting event made up of two disciplines. Biathlon usually refers specifically to the winter sport that combines cross-country skiing and rifle shooting, but other popular variants include summer biathlon, which combines cross-country running with rifle, and biathle (also known as "modern biathlon"), which combines running with swimming.
Called military patrol, the combination of skiing and shooting was contested at the Olympic Winter Games in 1924, and then demonstrated in 1928, 1936, and 1948, but did not regain Olympic recognition then, as the small number of competing countries disagreed on the rules. During the mid-1950s, however, biathlon was introduced into the Soviet and Swedish winter sport circuits and was widely enjoyed by the public. This newfound popularity aided the effort of having biathlon gain entry into the Winter Olympics.
All cross-country skiing techniques are permitted in biathlon, which means that the free technique is usually the preferred one, being the fastest. No equipment other than skis and ski poles may be used to move along the track. Minimum ski length is the height of the skier less 4 centimetres (1.6 in). The rifle has to be carried by the skier during the race at all times.
The biathlete carries a small bore rifle, which weighs at least 7.7 lb, excluding ammunition and magazines. The rifles use .22 LR ammunition and are bolt action or Fortner (straight-pull bolt) action. The target range shooting distance is 50 metres and there are five circular targets to be hit in each shooting round. On all modern biathlon ranges, the targets are self-indicating, in that they flip from black to white when hit, giving the biathlete as well as the spectators instant visual feedback for each shot fired.