Parkour is a physical activity that is difficult to categorize. It is often mis-categorized as a sport or an extreme sport; however, parkour has no set of rules, team work, formal hierarchy, or competitiveness.[4][5] It is an art or discipline that resembles self-defense in the ancient martial arts.[6][7] According to David Belle, "the physical aspect of parkour is getting over all the obstacles in your path as you would in an emergency. You want to move in such a way, with any movement, as to help you gain the most ground on someone or something, whether escaping from it or chasing toward it."[8] Thus, when faced with a hostile confrontation with a person, one will be able to speak, fight, or flee. As martial arts are a form of training for the fight, parkour is a form of training for the flight.[7] Because of its unique nature, it is often said that parkour is in its own category.
A characteristic of parkour is efficiency. Practitioners move not only as fast as they can, but also in the most direct and efficient way possible; a characteristic that distinguishes it from the similar practice of freerunning, which places more emphasis on freedom of movement, such as acrobatics.[9] Efficiency also involves avoiding injuries, short and long-term, part of why parkour's unofficial motto is être et durer (to be and to last). Those who are skilled at this activity normally have an extremely keen spatial awareness (a.k.a. air sense).[citation needed]
Traceurs say that parkour also influences one's thought process by enhancing self-confidence and critical-thinking skills that allow one to overcome everyday physical and mental obstacles.[4][10][11] A study by Neuropsychiatrie de l'Enfance et de l'Adolescence in France reflects that traceurs seek for more sensation and leadership than gymnastic practitioners.[12]