Parkour is defined as the efficient movement towards a certain point to another in the case of an emergency, such as a chase or reach scenario. The movements utilized include sprinting, running, vaulting, jumping, climbing, quadrupedal movement, rolling, etc. All natural human movements can be considered as Parkour as long as these are efficient, thus decreasing energy expenditure, time, distance, or danger to the practitioner or traceur.
It can be argued that Parkour, in its most essential form, has been around since pre-historic times, because human beings have always been looking for the quickest way to get from A to B. However, Parkour as a discipline has only been around since David Belle founded it as such. Belle was greatly influenced by his father, Raymond Belle, who was taken in by the Army when he was separated from his mother during the division of Vietnam in 1954.
Raymond Belle completed his military education in 1958, and he went on to join the sapeurs-pompiers, which is the French fire service. Raymond Belle joined the elite team, which was made up of the most skilled and agile firemen. He soon became a well respected member of the sapeurs-pompiers and inspired the younger generation, especially his son, David. Raymond taught David about the Natural Method and encouraged David with stories of heroism. David was also introduced to gymnastics, martial arts and obstacle course training. Raymond also told David about Georges Hébert.
Georges Hébert was an officer in the French Navy and he spent a great amount of time travelling and came across several different cultures. He was especially impressed by the indeginous people of Africa, as he found that they were agile, nimble, supple, flexible and had splendid bodies, yet they had no coach but nature. This inspired Hébert to create a physical culture training system whilst at sea.
Upon his return to France, Hébert became a Physical Education tutor in the college at Reims, which allowed him to teach his 'natural method' to others. He was opposed to the idea of remedial gymnastics, as he believed that they did not allow the body to develop in a harmonious way.
After leaving school, David went to join the Lisse commune, where he continued his journey with several friends. In 1997, the group Yamakasi was born, the group was made up of David Belle, Sébastien Foucan, Yann Hnautra, Charles Perrière, Malik Diouf, Guylain N'Guba-Boyeke, Châu Belle-Dinh, and Williams Belle. The name Yamakasi comes from the Lingala language of Congo, and means strong spirit, strong body, strong man, endurance. After the musical show Notre Dame de Paris, Belle and Foucan split up due to money and disagreements over the definition of l'art du déplacement, resulting in the production of the film Yamakasi in 2001 and the French documentary Génération Yamakasi to be without Belle or Foucan.
Over the years, as dedicated practitioners improved their skills, their move-set expanded and evolved. Building-to-building jumps and drops of over a story became common in media portrayals, often leaving people with a slanted view of parkour. In actual fact, ground-based movements are more common than anything involving rooftops, mainly due to accessibility to find legal places to climb in an urban area. From the Parisian suburbs, parkour became a widely practiced activity outside France.
 Physicality of the discipline
Due to the nature of the discipline, it can be considered as very stressful for the traceur's body, for this reason complimnetary strengthening and conditioning is recommended by some. However, the parkour community seems to be divided when it comes to this subject. Most of the practitioners opt for only parkour and techniques as a means to strengthen the body, and while this method does work to a certain point, it is certainly obsolete at increasing the total amount of strength and power in a prolonged amount of time. There is also a big controversy as to include weight lifting as training regiment for parkour, but over time it seems to be gaining momentum in some communities and amongst some practitioners, which is a big step from the all bodyweight regimes followed by most practitioner, which again is not bad, but then again there are more "efficient" ways to obtain strength and other skills.
Parkour differs from a sport only because it has a philosophical aspect to it. Parkour was originally created as a means to help others, to be useful to others as well as for oneself. However if this was the case, most traceurs would train differently. Rather than doing a jump countless times, they could develop more overall physical preparation, in order to use it in any given situation that is needed. Also the concept of being useful to your fellow should not disappear as soon as training is over, it should be something that the traceur should does in his daily life. Practitioners also say that parkour helps overcome life's problems by making you confront obstacles in your personal or daily life, just like you would outside while training.