NEVER SWIM ON A STOMACH FULL OF BOOZE AND TROPICAL DIARRHOEA

I've never eaten a horseburger. I've had peacock, crocodile, buffalo, kangaroo and KFC, but no horseburgers. Slovenia's Martin Strel eats horseburgers. He also drinks two bottles of wine a day, and says "Fat is my power". He also swims four kilometres an hour, five hours a day, and, to raise awareness about pollution and the destruction of rainforests, swims the world's most dangerous, dirtiest rivers. After previously taking on the Mississippi and the Yangtze (which saw him swimming amongst human corpses), in 2007, aged 52, he was the first person to tackle the Amazon, where he swam 5,268 kilometres in 66 days.

The Amazon at the time was experiencing its worst flooding in 100 years, causing the banks to cave in, filling the water with tangled bits of forest, tarantulas and scorpions. Birds pecked his face and piranhas ate his back, and he had to navigate snakes, crocodiles and candiru fish. Thankfully, American documentary maker John Maringouin was there to chronicle it, and the resulting film, Big River Man, one of the most entertaining documentaries I've seen in ages, just came out on DVD.

Continuing his swim despite ongoing medical advice to stop, Martin deals with dangerously high blood pressure, constant dehydration (not helped by his insistence on drinking whiskey and beer), second-degree sunburn, delirium, hallucinations, and a larva infection in his brain. Among the crew are Martin's son/assistant, Borut, and his "professional amateur" navigator – a poker player from Wisconsin who, somewhere along the way, loses his mind and turns into Dennis Hopper from Apocalypse Now. It's a great documentary – surreal, exciting, funny and inspirational – with music that sounds like outtakes from Neil Young's Dead Man score (in a good way). I called up Martin to talk about it all. With him were Borut and Martin's health and business adviser, Kathy.

Vice: Hello Martin. You say you never get hurt or sick. Are you lying, or do you have special powers?
Martin: Hello, Martin is here. With regards to have met you. Yeah, it's not completely true, I have thousands of problems, but with me it's a little different; I could be sick, I could be terribly sick, but you know, I have to swim every day. There's no question. In the Amazon there were a lot of problems – so much diarrhoea – but these are small problems, you have to swim.

You're generally very healthy though?
Yeah, maybe I am a little different to regular people, maybe I was born like this, but I live pretty well, pretty healthy; I spend a lot of time in the forest, nature, water. I eat and drink pretty good. I'm never sick, my body is maybe a little stronger.

Maybe it's all the horseburgers.
Yeah! Horseburgers is good food.

So it's been a good couple of years since you swam the Amazon. What have you been doing since?
Bringing the message around to raise awareness for clear waters. Swimming in Greece, Norway, and UK too – Thames. I swam Thames two times.

Was that clean?
Yeah, Thames is pretty good river now. Good smell, pretty clean, a lot of fish inside.

That must have been a refreshing change for you. What was your lowest point when you did the Amazon swim?
The hardest problem was all the tropical diseases. This is not nice for us, even though it's a beautiful part of the world. It's beautiful, but it's for indigenous tribes, it's not for us. So many mosquitoes, humidity is terrible, the sun is unbelievably strong – 100 degrees Fahrenheit.

You looked pretty low when you plugged a battery into your head.
Yeah, 66 days without a break, you can get pretty bad. The Amazon was terrible for my head, for my brain. It made me nervous, everything around me, what it was possible to touch, to put in my head, to change my mind.

Was there a point where you wanted to give up?
This is a very very hard question for me; for me, it almost doesn't exist. For me, it's a big big problem to say, "No more, let's go home."

But you wanted to?
No, no. Of course there were very terrible days when bad things happened, but I'd have to reach zero to give up.

I'm told you didn't like the way you were portrayed in the film.
This is a Hollywood thing, to have me driving drunk is not true. I drink wine, it's true, but the stuff about the police stopping me, it's not true. But that's American people, they were an American crew.
Borut: Can I say one thing? I was doing the voiceover narration for the film, and I'm his son telling this story about Martin being drunk and alcoholic. But the truth is that I was told to read the narration without seeing any footage, and at that time I had no idea that I had any right to say what could or couldn't be in the film. You have to understand that we had no experience of filmmaking before. The filmmakers took advantage of that, and we are not hiding that.

So you were saying stuff that wasn't true?
Borut: Oh absolutely. I was reading pages and pages and pages of scripts and I was almost not even able to think about what I was reading because they gave me so much. But I wanted to participate with whatever had to be done to get the film out to show Martin swimming the Amazon. But we didn't see the film until it premiered at Sundance. They were purposely hiding things and not showing us how Martin would be portrayed. On one hand, this is their right as filmmakers, but it's not fair to us because this is damaging to Martin. People think this is who he is, and he's not.
Kathy: I'm an American and I'm just gonna say this, because I did not know Martin and Borut at the time when this was happening, and there's just no other way to say it, they were very naive in their understanding of how business people in Hollywood do things. And like Borut said, he was absolutely bombarded with reading material and didn't think enough about how they were portraying his father in a light that was absolutely not true.

So is this stuff exaggeration, or were they actually making stuff up?
Kathy: Let me tell you, Martin has great respect for life. Martin never gets drunk. Never. Martin never drives if he has had even wine. And, by the way, the wine that he drinks is, I would actually call it a medicinal wine, it's a very, very low alcoholic content wine from Slovenia, so absolutely that was completely made up. And in reference to him being a gambler and gambling away money, first of all, he did not get the money they said he got; we don't know who got it, but he did not get it. One of the sponsors is someone he knows who is a friend and has a casino, and they asked Martin to do some footage there. But Borut read some things that should not have been read, because of naivety.

OK. Martin, at the end of the film you're having recurring dreams about the Amazon. Is that still happening?
Martin: I'm still in the water every day. Amazon was a very very big risk for me. It was 50:50. I decided to do it, and I'm still alive. Believe me, I'm in the Amazon still every day. It was very big risk. I'm still alive. I still train every day, but if you ask me what I do tomorrow, it's a big question. Believe me, I'm still in the Amazon, my mind is not so clear about swimming tomorrow. It was dangerous for me.

Well it's an unbelievable achievement, and it's amazing to see it on film. It's been great talking to you all.
Kathy: May we give you Martin's website to put up, because we're going to be releasing some pretty important information. For example, we'll be disclosing what Martin actually consumes on a daily basis.

Sure.
Great, it's martinstreladventures.com.

I did attempt to talk to director John Maringouin to get his side of the story for this interview, but couldn't get hold of him.

ALEX GODFREY