Chi Running evolved when a tai chi-practicing ultra-marathoner decided to apply principles from the Chinese system of slow, smooth movement to his running.
The resulting method, which enthusiasts hail as effortless and injury-free, is as specific in form as it is insistent on going with the flow.
"My goal is to turn running into a mindful practice, like tai chi or yoga" said Danny Dreyer, the runner and coach who developed Chi Running and wrote the "Chi Running" book.
"We teach focus: how the arms are held, why the hips and shoulders are relaxed," he said. "It's about learning to pay attention."
Dreyer, who is based in Ashville, North Carolina, said more than 200 instructors worldwide teach his technique, which enlists the Chinese principle of "chi," or energy flow, to reduce injury and enhance ease of movement.
"In tai chi, everything moves from center," Dreyer said. "Runners are used to running from their legs. When I switched to (running from) the core, it changed how I ran. I felt better."
Correct alignment is a tenet of chi running. Posture is the first thing Dreyer works on with clients.
"If posture isn't good, the support system isn't good," he said. "Any weakness or misalignment will really affect you because you're always on one leg," he said, noting that running injuries happen from the knees down.
In his method a forward tilt from the ankles moves the runner's center of mass ahead and allows gravity to take on more of the body's weight.
"The body gets to fall," Dreyer said. "All you have to do is lift your legs."
He also teaches landing with a mid-foot strike to engage and balance the entire foot.
If you're new to running, Dreyer suggests starting with a walk/run sequence to allow the muscles to adjust.
"Run 'til you feel tired, walk 'til you feel recovered," he said. "Our system is based on sensing your own body. If your body says it's too fast or time to go home, you listen."
A runner for 20 years, Chris Griffin said before he discovered Chi Running he was getting injured "on a regular basis." Now he's running injury-free, and faster.
"I knew how to use my body but not how to listen to it," said Griffin, who teaches the method in Marin County, California. "Being focused changed my running from a sport to a practice."
He no longer waits for his body to "crash" to pay attention. Griffin said he doesn't do tai chi but is always "playing around with the energy," and cultivating mindfulness in non-running situations.
"How do I stand in line at store? How do I interact with people? If I'm picking up a bag of groceries I'm trying to be emotionally and mentally aligned," he said.
Connecticut-based exercise physiologist and running coach Tom Holland is a fan of the mind-body connection Chi Running cultivates, but falls out of step with what he sees as the one-stride-fits-all method.
"I think there's no one way to run," said Holland, author of "Beat the Gym" and "The Marathon Method."
He cited a recent study that placed a camera at the 20-mile (32-kilometer) mark of the Boston Marathon.
"It showed all the top runners and not one of them ran the same way," he said. "The truth is there is no one way to do it." Holland believes modern runners' injuries stem mostly from imbalances brought on by inactivity.
"Running is the purest example of what our weaknesses are," he said, most commonly in strength or balance or flexibility. "If we go out for a run and I'm not correcting form people will feel it. Then we fix it."
Sports-specific, strength training exercises work for many people, he said, adding that there's a wealth of such programs available in books and online.
"So many peoples say 'just run,'" he said. "No one taught the cavemen how to run...But if you're not built for it you're going to have problems."
Dreyer wants his method to connect us with how we ran as children.
"Kids have gorgeous running form and they don't get hurt," he said. "As kids we all ran really well."