Hikers exploring the Canberra hills should not be alarmed if they come across a man wearing no shoes, scrambling through the scrub.
Unlike most joggers and walkers, who prefer the safety and convenience of man-made tracks and padded soles, the local athlete Brad Osborn enjoys scurrying through the bush, jumping over logs and crawling underneath branches.
"People think I'm crazy but the ability to connect to the earth … and the capacity to run through any terrain barefoot is one of the things [this workout] gives you," the decathlete and volleyball coach says.
"Running through the bush engages every part of your body and mind because you have to be completely aware of every point of balance - it's shifting all the time."
Osborn's unusual training techniques are part of a growing international movement called MovNat. Founded by a French trainer, Erwan Le Corre, about four years ago, it encourages natural, functional exercise in an outdoor setting. It also promotes a paleo-style diet, which is based on hunter-gatherer foods such as meat, vegetables, fruit and nuts.
About 250 people around the world have become official instructors since qualifications were introduced in May this year. Two Australians, Tanya and Andrew Carroll from Victoria, hope to complete a formal certification course in Singapore in February.
The system is based on 13 cardio-, strength- and flexibility-based movements that can be done with or without a partner. Locomotive skills include walking, running, jumping, crawling and swimming; manipulative skills include lifting and carrying; and combative skills include striking and grappling.
The method teaches practical movements based on how humans used to move in nature or childhood, says the instructor Vic Verdier, who runs public workshops all over the world. These can be adapted for indoor and urban use but are preferably done in natural settings, where each workout is adjusted to a particular terrain. No special equipment is necessary, he says.
The focus on outdoor exercise separates MovNat from similar sports such as parkour and CrossFit, Verdier says. "After a while of living in an artificial world in an artificial way, we tend to live a very artificial life," he says.
"What we try to do … is relearn the way we used to live and move in general. It doesn't mean we want to live like cavemen or anything stupid like that. It just means we spend too much time sitting and too much time in an artificial environment and therefore most people just don't know how to move [any more]."
"Every run is different," says Osborn, who has completed MovNat workshops in Australia and the US. "I don't follow a route. You run completely differently than if you're running on a track or treadmill … instead of repetitive motions and fatiguing muscles you're actually engaging your entire body."
Tanya Carroll, a trainer from Livestrong Primal Fitness in Melbourne, says the method caters to every level of skill, from beginner to advanced, but there is no formal hierarchy. It engages people's imaginations, is not competitive and can be used to supplement other sports and exercises, she says. Most of her clients fall into the 25- to 35-year-old age bracket, with just as many women as men showing interest.
The outdoor extremes in Australia can sometimes prove a challenge, however.
"Obviously that's something we have to be aware of," she says. "With our weather we have to be careful about exposure to the sun so it's not something I'd be doing in the middle of summer on a 40-degree day, but you work around that."
Others also warn that the system may not suit everybody. Chris Tzarimas, the director of the lifestyle clinic in the faculty of medicine at the University of NSW, compares it to commando-style training that is most likely to appeal to fit and able-bodied people.
"It's not a bad thing," Tzarimas says. "But you have to appreciate the inherent risks in what they're doing. It's great for people who are adventurers but trying to promote this as a mainstream fitness activity [is] getting a little ahead of ourselves."
For Osborn, however, the technique promotes a unique combination of full-body fitness, mind-body awareness and a connection to nature.
"For me, the ability to be an all-round athlete has always been important," he says. "The philosophy … is not about competition or specialisation - it's about being capable in all situations."