I run across the brick sidewalk and leap down a short flight of steps, landing like a cat. Gently, I touch down on all fours with my hands slightly forward of my feet, crouching low to absorb the impact, my back arched up, ready to spring again. Piece of cake!

I race on and vault a metal railing, swinging my legs over one side before dashing at a seven-foot-high concrete retaining wall. My feet hit the wall in two vertical running steps as I reach for the top. My hands press onto the concrete ledge, and I push up my torso as if I'm climbing out of a swimming pool. In a second, I'm on my feet, running again.

No, I'm not being chased by the cops. This is free-running, aka parkour.

In a courtyard next to the Bethesda Metro, I'm tackling this extreme sport, which started in France about 10 years ago as a new way to interact with the environment, especially in urban settings.

Parkour's main focus is fluidity of motion and staying on one's path no matter what impediments are faced. Architectural structures are merely pieces of gymnastic equipment to jump over or wiggle under. The sport is the physical manifestation of an age-old philosophy: On the path of life, one is constantly faced with obstacles.

Though most local free-runners are young men in their teens and early 20s, anyone can try it if they're agile enough. I wish this sport had been around when I was a kid. I would have had an answer when my mother asked me questions such as, "Why did you jump off the shed roof?" "It's philosophy, Mom!"

What to Expect: In the beginning, keep it simple. There aren't any parkour schools or teachers, but the basic running and jumping and scrambling are fairly easy and intuitive. Advanced free-runners, aka "traceurs," leap from rooftop to rooftop over alleys like Spider-Man, and run up the corners between buildings like Jackie Chan. But that's not where you want to start. Traceurs spend a good deal of their time working out individually and at training sessions -- lots of running and stretching, squats, weight training and abs work. Vaults are usually practiced at a gym.

To prep for my parkour experience, I joined an afternoon training session at Xtreme Acro and Cheer Gym in Rockville with a few traceurs. There I learned how to perform a monkey vault -- a leap where you tuck your knees to your chest as your hands land on the vault and then swing your legs through your arms. I also practiced precision jumps by attempting to land on a narrow bar and tumble rolls on the ground to break a fall. After warming up, I tried a wall spin -- a move where you jump and plant your hands on the wall and then rotate your body around your hands like a spinning top. My practice efforts went well enough, but when attempting the actual spin, I hesitated and fell, landing hard on my back. Ouch.

More advanced movements are learned through watching videos on the Internet and getting together with other traceurs at jams and training sessions scheduled through Web sites.

Staying Safe -- and Legal: In a few days of trying parkour, I skinned both elbows and a knee, banged my shins trying a "cat climb" on a stairway railing and picked up a couple of black and blue marks. It's definitely a younger person's sport. And even youthful healthy people need to think safety more so than daring. After seeing my scabs and bruises, my wife asked what happened. "It's philosophy, dear," I replied.

Parkour has gained popularity in the mid-Atlantic within the last two years. But even in this short time a spirit has developed that emphasizes no law-breaking, no trespassing and the leave-no-trace attitude of backpackers. If the police or security guards question participants, generally the traceurs have been allowed to continue after an explanation of the sport.

What to Wear: Long, loose-fitting running pants are best to avoid skinned knees. Wear good running or trail shoes with ankle support. This will help prevent some of the most common injuries: twisted ankles, sore joints (especially knees) and shin splints.

Matthew Graham

Resources

* parkour.net. Lots of great videos by the world's best are here.

* www.urbanfreeflow.com. Visit "the basics" link on this Web page to see fundamental moves.

* www.va-parkour.com. The local traceurs' Web site. Check out the forum to meet free-runners, learn moves and set up a training routine.

* Xtreme Acro and Cheer. This gymnastics and cheerleading gym has open sessions for parkour training on weekdays, noon-1 p.m., and Saturday 6-7:30 p.m. 20-E Southlawn Ct., Rockville. $5-$7. 301-251-5525. www.xtremeacroandcheer.com.

How boring to just walk up a flight of stairs. With feline agility, Matthew Graham does a cat climb to get to the top of these steps in Bethesda.