Simplify the following text for a Grade 8 native English-speaking person.
Original: Parkour is an activity in which the goal is to move from one place to another as quickly and efficiently as possible , using the abilities of the human body . Parkour helps to overcome barriers , and is practiced in rural and urban areas .
Simplified: Colorado Parkour began a project to introduce parkor into the U.S. military and parkor is slowly being introduced into the United States Marine Corps .