A Mount Laurel native, Wilczewski, 23, opened the gym in January as a "passion project." He has been practicing parkour for several years and recognizes the impact it has had on his life - not only gaining him fame but reshaping his life for the better.
While a freshman at St. Joseph's University, Wilczewski said, he began to consume alcohol in excess.
"It didn't really get bad until I went away for college," said Wilczewski, who started drinking in high school. "I needed some sort of outlet, and this helped me get away from it and stop drinking completely."
In October, Wilczewski will be two years sober. He credits parkour for providing him focus and discipline.
Mark Toorock, the founder of American Parkour, a Washington company and hub for the parkour and the free-running community, calls it just that: a discipline.
But Toorock noted diverging opinions about what exactly parkour (pronounced par-coor) is. Some label it a sport, he said, or define it by the swift and agile movements associated with it.
"Very rarely do we mention the word exercise. . . . It doesn't feel like exercise; it feels like fun and play," said Toorock, 41. It's a "training method - training your body and mind using physical obstacles as the medium."
Parkour has proved useful for many, including Toorock and Wilczewski, who advanced to the semifinals and finals, respectively, of the obstacle-course-based reality show American Ninja Warrior on G4 and NBC, Toorock said.
Wilczewski became seriously involved with parkour after falling short on American Ninja Warrior 2, his first attempt at the show.
"I kept thinking about this one Eminem song, where he references 'Back to the lab again,' " Wilczewski said. "That's what I wanted it to be: I wanted to go back to the lab. I wanted to rebuild myself, make myself better and just more ready for life in general."
Now a health and exercise-science major at Rowan University, Wilczewski has participated in the subsequent seasons, most recently making it to the Las Vegas finals of Season 4. He can't discuss the results of the competition until the final episodes air this month, but he said he's happy with where he placed. Because of his success on the show, his gym offers a special American Ninja Warrior training class on Saturdays.
The Warrior Lab has more than 20 regular members, many of whom are males between 11 and 17. But the gym is trying to appeal to other demographics, too. It now offers an all-women's parkour class. Wilczewski plans to move into a bigger space and purchase more gymnastics equipment, if membership growth allows it.
Wilczewski and others from the lab will do a performance and introductory class for children and teens at the Mount Laurel Library on Saturday. Participants will learn basic parkour moves, such as rolls and quad steps.
He did a similar event in the fall after teens in a library advisory group said they were interested in parkour, said Samantha Marker, manager of the library's teen and tween services.
"A lot of them had seen [parkour] YouTube videos," said Marker, who was unfamiliar with parkour before planning the event. It was a "blessing," she said, that Wilczewski, whom many of the youths recognized from TV, was from the area. The event drew about 50 spectators and 20 young participants.
In recent weeks, Wilczewski visited Washington to obtain certification from American Parkour. Toorock said his company began offering certification this summer to better prepare teachers of the discipline.
Yet Wilczewski said teaching had come naturally. He has grown from teaching others in parks and his backyard, to operating a class at a local gym, to opening the Warrior Lab.
His younger brother, Brian, a 20-year-old studying mechanical engineering at the Rensselaer Polytechnic Institute in New York, recalled when his brother introduced him to parkour. The two recorded videos of their parkour outings and stunts on their backyard course. They laughed discussing their first few videos, looking back on them with both endearment and embarrassment.
Brian Wilczewski now helps operate the Hainesport lab and plans to try out for American Ninja Warrior after he's 21, the series' minimum age. While away at school, he continues to practice parkour.
"The beautiful thing about parkour," Chris Wilczewski said, "is that you can take it anywhere."
Contact Angelo Fichera at 856-779-3814, firstname.lastname@example.org and on Twitter @AJFichera.