With a flick of his wrists and a firm grip, Robert Hoover grabs a bar, straightens his legs and holds his body horizontally in the air.

It’s a parkour move called “human flag” that the 41-year-old Dale City man didn’t think he could master when he started trying out such moves six years ago.

He didn’t think he’d ever be a contestant on NBC’s “American Ninja Warrior,” either. And now Hoover, an engineer, pastor, musician and father, has competed on the show twice.

“I saw a video of ‘American Ninja Warrior’ and all of a sudden realized, ‘Well, maybe I should try to do that,’ ” said Hoover, who competed on the show last year and again last month.

The program, a spin-off of a Japanese competition called “Sasuke,” has nothing to do with being a ninja and everything to do with parkour — a style of urban gymnastics that started in France and spread globally over the past decade. Participants use man-made obstacles such as street signs, lamp posts and playground equipment to execute moves.

Robert Hoover, 41, of Dale City competed in NBC's American Ninja Warrior competition. A longtime parkour enthusiast, Hoover, who is an engineer, pastor and musician, often trains with his 9-year-old son, Devon. (Victoria St. Martin/TWP)

“I don’t think of myself as a ninja warrior,” Hoover said. “I would call myself an athlete.”

Hoover won’t say how far he made it in the show’s sixth competition — to find out, he says with a chuckle, people will have to tune in.

“American Ninja Warrior” features obstacle courses with such names as the Salmon Ladder, Warped Wall and Cliffhanger. “When you get there, it’s like ‘Wow,’” Hoover said. “The scaffolds are 30, 40 feet high.”

To his 9-year-old son, Devon, Hoover will always be more dad than TV warrior. The two often train together at the Urban Evolution gym in Manassas. Devon sets up the courses, and Dad follows closely behind: Use your momentum here, lean there, put your arm over for balance.

When he’s competing, Hoover’s computer and mechanical engineering skills often come into play.

“When I’m on the course, I try to reverse-engineer the obstacles,” he said. “You try to watch what other people are doing, how their bodies are moving and try to figure out the most effective way or the safest and most conservative way to get through the course.”

For Hoover, moving is a lifeline.

“I don’t feel alive unless I’m moving,” he said. “I’m always dancing or moving or doing something, so parkour is a way of moving through my environment in a fun way.”

Hoover got started with parkour after his wife, Anne, showed him a YouTube video. Soon he was taking lessons at a gym and learning new moves from other videos. He usually tests things out in his back yard or on the streets near his Dale City home — walking on top of swing sets, hanging from poles and boards.

For him, there are no obstacles, just objects to adapt to. You jump over them, slide under them or figure out a new plan. And keep going.

“You just kind of go with it,” Hoover said. “Instead of trying to fight and change something or stop, you kind of just let your momentum carry you, and you follow it through, and you move on to the next obstacle or wherever you’re going.”

“I do it because it’s fun,” he said.