Long-distance running confined area. Early tracks were usually on flattened earth or were simply marked areas of grass. The style of running tracks became refined during the 20th century: the oval running tracks were standardised to 400 metres in distance and cinder tracks were replaced by synthetic all-weather running track of asphalt and rubber from the mid-1960s onwards. It was not until the 1912 Stockholm Olympics that the standard long-distance track events of 5000 metres and 10,000 metres were introduced. Long-distance road running competitions are mainly conducted on courses of paved or tarmac roads, although major events often finish on the track
800 metres have been known to use a negative split to their advantage. A positive split is achieved by running the first lap faster than the second lap, and a negative split is achieved by the opposite, running the second lap faster than the first could help. The current world record holder, David Rudisha, runs using a positive split strategy. In his 2012 Olympic race, he ran his first lap in 49.28 seconds and his second lap in 51.63 seconds. Theoretically, an even split is the most effective strategy, but it is nearly impossible to achieve due to the race's length. As