COLUMBIA, Missouri (Reuters Life!) - For student Mike Heaviland a picnic table presents a unique challenge -- should he try a monkey vault to a precision landing, or an advanced kong vault, lunging over it head first?
The dilemma for Heaviland is part of practicing parkour, a gritty urban sport in which the city is the gym, which has gained popularity on U.S. college campuses.
For parkour enthusiasts balconies become balance beams, handrails double as high wires and rooftops become launching pads.
With college campuses back in full swing this autumn, parkour's appeal to students is adding to the ranks of followers, but there are growing concerns about the dangers of the sport.
Devotees say parkour strengthens the body and the mind, training both in efficient ways to overcome obstacles.
"There's no winning and losing," said Heaviland, who founded the parkour group at the University of Missouri in January. "It's more about self-improvement than anything else."
The sport, which was imported from France, now has clubs in California, New York and other states. The five-year-old American Parkour organization counts 65,000 registered users.
It evolved from an obstacle course for the French military and was devised by Georges Herbert, a French naval officer in World War One. Parkour gained fame among urban French youths before crossing the Atlantic.
Practitioners are known as traceurs, from the French word meaning to draw, trace, or go fast. Enthusiasts share videos of their most daring moves, and most painful falls, on websites. Facebook has a page dedicated to parkour, and the cable television channel MTV has been sponsoring a nationwide ultimate parkour challenge.
"It has definitely gained a small but dedicated following in the states that seems to be growing every day," said Sean Ehrlich of Florida State University.
Supporters say parkour is a fun hobby and good exercise, but others believe it is dangerous.
A student at the University of Illinois at Urbana-Champaign (UIUC) died in October 2006 on campus after scaling a chain link fence and leaping from a tower to his death. Police suspected the man could have been practicing parkour.
"We did know about parkour being practiced on campus at the time of the student's death, but the fact is we can't be constantly watching our towers and parking garages for activity like this," University police spokesman Skip Frost said.
Although UIUC has continued to allow parkour groups to practice on campus, several other student organizations have faced opposition and some cities have tried to discourage parkour enthusiasts from practicing in parks and on public property.
The University of Washington refused to recognize the sport as a club and the University of Texas at Austin has asked its students not to train on campus because of concerns about liability.
Many of parkour's followers say they were originally inspired by daring YouTube videos with titles like "Urban Ninja."
"Parkour is much more then the sport it's come to be defined as," said James Redenbaugh, who founded a parkour group at Syracuse University this spring. "For me, parkour is a way of life."
Reporting by Zach Toombs, Writing by Carey Gillam; Editing by Patricia