I'm thinking the guys before me don't even practice
parkour in the first place...
Parkour is
not a sport, in that there are
no rules, teams, or points. It is not about competition or showing off.
It shouldn't be confused with
freerunning.
Freerunning is more about free-movement and involves more
tricking.
Parkour can be thought of as being chased by someone. You want to get away as fast as possible, right? But lets say you begin running into rails or walls or other obstacles as such. If you go around them you're only wasting time and energy.
The trick of parkour is to use as little wasted movementt while going past an obstacle. This is why most consider tricking and flips "not parkour" as they simply aren't necessary and will most likely slow you down in someway.
To parkour is to be able to control your body and mind into one being, so that you can find a path quickly, and move your body in a way that the path can be followed into the next path you're given. If you're running towards and obstacle and start to slow down in order to maneuver around it, most likely you need to practice more.