Maybe it’s the views. Or the sheer space around you, empty and vast. Or the rain, and the mud, and the rocks and the steepest rock faces you’ve ever seen, or the dark, and the feeling of being absolutely alone.

Maybe ultra trail runners are just mad. Who else but the truly deranged would take on such incredible odds? Most high-profile trail races in South Africa set a standard of ultra-marathon distances at a few thousand metres above sea level, in some of the country’s most remote locations and in extreme, unpredictable conditions. Forget a flat track to run on, forget water stops and route markers and thousands of fellow sufferers to share your pain. On top of that mountain, it’s only you and all that you can carry.

This is what drives AJ Calitz, recent winner of the 65km Hout Bay Trail Challenge and current holder of the Red Bull Lionheart crown: an instinctive need to bust out of the city’s limits. “I love the looks you get,” he says. “When you’re running through traffic, heading up the mountain, all these people sitting in their cars thinking, What the hell? My question is, what the hell are you doing in that car, man?”

“Our bodies are designed to be incredible all-terrain vehicles – trail running is going back to the root of what we were created to be.”

Or maybe it’s the fact that trail running makes you better. Many studies have shown that living amongst tall buildings and heavy traffic can make you ill with anxiety, and that simply running through roads from one urban area to another does little to alleviate the stress of city life. So to see if prolonged exposure to nature can help reverse that effect, scientists compared two groups of people: one went for a long run in a natural setting, and the other ran through city streets. They published their results in 2015 in the Proceedings of the National Academy of Sciences – and found that people who regularly run long distances outside, surrounded by nothing but trees and an open trail, showed significantly decreased activity in the subgenual prefrontal cortex, an area of the brain associated with mental illness.

Local trail phenom Ryan Sandes knows this well. “Trail running helps keep my mind clear and not be afraid to dream,” he says. “I’m quite a control freak, and running trails helps me forget about that and just enjoy. Especially running distances over 100km – it brings out the true person I am. I think everyone should experience an ultra in their lives. The world would be a better place.”

It’ll also make you fitter. As opposed to road running, which can restrict your body in becoming more and more efficient in a single direction, trail running requires the strength, agility and just plain athleticism to leap over and around fallen trees, navigate broken-up rocks and climb inclines that go up forever. To do it effectively, you’ll spend a lot of time in the gym, working predominantly on all-over strength, and the benefits of that carry over into all aspects of life. “Trail running is dangerous; the conditions are ever-changing, and the terrain is taxing on the body,” says Chris Lippstreu, owner of Cape Town’s Race Fit, where he trains endurance athletes to get stronger. “It’s not just about your legs – whether you’re scrambling up a rocky ravine or descending a technical rock garden, you need to be seriously strong all over to stay upright and keep moving forward.”

Running for days up and over a treacherous mountain, no matter the weather, sounds almost sadistic. To put your own body through something like that, surely you’d have to be just a little crazy? As Calitz explains, there’s a unique kind of victory waiting for you up there. “I see a mountain, I want to run it. Running where no one else has run before is a little like sticking a flag in the ground and claiming it. It’s a way of saying, I was here. Were you?”

Picture courtesy Jacques Marais