It's considered one of the hardest foot races in the world.

Runners in the Barkley Marathons are given a map, a compass and set loose in the Tennessee wilderness. They're expected to cover more than 210 kilometres over three days.

In the 30-year history of the race, only 14 people have ever finished. And this year, Canadian Gary Robbins was almost one of them.

Here is part of our interview with Gary Robbins from Vancouver:

Laura Lynch: Do you have a death wish?

Gary Robbins: I don't have a death wish, but I definitely really appreciate being pulled to my outer limits and having to face things front on and really discovering a side of myself that you're just never going to see in day-to-day living.

LL: Give us an idea of what it was like for you after more than 25 hours trying to bushwhack through the wilderness.

GR: I had been facing hallucination issues for 24 hours and it became very difficult to rationally think my way through a map and compass. While I was running with another runner . . . I forgot who I was actually with.

I was following him through the night and I couldn't recall who in the world was in front of me. And I eventually said, 'I have no idea who you are.' And his response was, 'I'll be whoever you need me to be. Let's just keep moving forward together.'

Coincidentally, 24 hours later, on his final lap he forgot who I was. We spent 47 hours together and we couldn't recall who the heck the other guy was.

Gary Robbins follows Barkley Marathons legend, Jared Campbell, up one of the toughest climbs on the course, known as 'Rat Jaw.' (Keith Knipling )

LL: You said you were having hallucinations. Tell me what the hallucinations were?

GR: So you start constructing things in your mind in the forest that don't exist. Anything with two holes in it became a face. I would in my mind construe a face in leaves and foliage and everything around me.

Any time there were lots of rivers, I would think that I was hearing celebration or groups of people. It really started playing with my mind because I knew I was in the middle of the forest and there was nobody out there, but my brain kept thinking it was hearing people talking.

I started vividly seeing numbers on trees. I would look at a tree and see the number 26 on it and look at another tree and see the number 88 on it. The mind does crazy things when it's sleep-deprived.

Gary Robbins re-fuelling during the Barkley Marathons endurance race at Frozen Head State Park in Tennessee. (Keith Knipling)

LL: How did you finish in the race?

GR: So I ended up getting lost. I lost about two-and-a-half hours of time just kind of going in circles in the forest. And I timed-out on that 60-hour cutoff.

I ended up being, to the best of my knowledge, only the fourth person who's ever made it to the fifth lap in their first attempt.

And I've been told that there's never been someone who's made it to the fifth lap, not finished and then not been able to return and eventually finish the race.

So, unfortunately, it's lining up like I'm going to do it all again in one year's time.

Click the link above to hear the interview in its entirety.

In 2014, a documentary film followed runners in the Barkley Marathons. It's called "The Barkley Marathons: The Race That Eats Its Young." Check out the trailer: