The British explorer reveals how a few burger-filled dreams and a little “Eye of the Tiger” took him to the edge of the earth and back.

In 2004, Mr Ben Saunders, then just 26, became the youngest person – and only the third in history – to ski solo to the North Pole, dragging a 180kg sled nearly 1,500 miles. A decade later, he completed a gruelling 1,800-mile, 105-day journey to the South Pole from Ross Island – a trek that both Mr Robert Scott and Sir Ernest Shackleton failed to complete.

“I’m an explorer of limits – geographically, physically and mentally,” says Mr Saunders, now 37, who calculates that he’s spent more than 2% of his life in a tent inside the Arctic Circle.

As a 21st-century reboot of the romantic 19th-century polar adventurer, Mr Saunders can teach us all a thing or two about drive and verve, and, indeed, his tales of epic endurance, coupled with a wry and genial manner, have made him a favourite on the motivational TED talk circuit. (Of his plan to make a solo and unsupported crossing of the Arctic Ocean, he drew laughs at one of his talks when he admitted that his mum wasn't overly "keen on the idea”.) Here, he talks to MR PORTER about what drives him to the ends of the earth.

The obvious question has to be: why do you do it?

And it’s the hardest one to answer. I loved being outdoors as a kid, growing up in Devon, and I was inspired by stories of adventure and exploration from a young age, including accounts of all the polar expeditions, from Scott to Ranulph Fiennes. But I was never sporty or picked for the football team. I remember an old PE report: “Ben is not easily motivated in this subject.” Then I got into cycling and running as a teenager, and found that I loved pushing and challenging myself.

Even so, “explorer” is rarely mentioned by career advisors as a viable option.

True, and you can’t do a degree in exploration. I guess it’s more of a calling. For me, it all coalesced when I worked as an instructor at the John Ridgway School of Adventure in Scotland. It was a kind of Outward Bound team-building centre on steroids, run by an ex-SAS man who’d trekked across the Patagonian icecap and was the first person to row across the Atlantic. Growing up, I’d been pretty low on male role models – my dad wasn’t around – so I sort of fell under the spell of these gung-ho adventurers, and wanted to emulate them, and even surpass them. I became obsessed with the Antarctic trek because only nine people in history had attempted it, and no one had completed it. But raising the seven-figure budget was hard, because people thought it had all been done. I’d talk to people about the South Pole, and they’d say things like “Oh, my granny’s going on a cruise there, perhaps you’ll see her.”

Presumably, the polar explorer kit is very different than the Shackleton era.

Oh yes. I've got GPS, titanium screws, down-filled sleeping bags and protein shakes, where Scott and Shackleton made do with tweed suits and cans of Heinz beans. My Bremont watch was also invaluable in Antarctica. Battery-powered quartz watches are prone to meltdown in the extreme cold, but chronometers with mechanical movements are ideal, as there are no batteries to go flat. I’d used a standard Bremont Supermarine on a handful of Arctic expeditions and was impressed by its toughness and reliability, but I wanted a watch that was super-light, antimagnetic (as I often navigate using a compass), and that had a third GMT hand that rotated once every 24 hours, to aid with solar navigation. It seemed a tall order, but Nick and Giles English, Bremont’s founders, relish challenges, and they came up trumps. We called the watch Terra Nova, after Scott's last expedition – I think Scott would have approved of the fact that they were made in Britain – and the first two were presented to myself and Tarka (my companion on the Antarctica trek) on the night of our leaving party.

You’ve described exploration as not too far removed from a crack habit – burning up money, ruining relationships...

Not my most sponsor-friendly line, but it’s true. It’s a kind of addiction. Though the Antarctica trip was the toughest yet. For the first couple of weeks, you go through these mountain ranges and landmarks made famous from previous expeditions. It’s like walking through Narnia. But the rest is a 360-degree flat nothing, like white desert. The weather was also oppressive – fog, whiteouts, blizzards.

What kept you going?

I had a load of drum’n’bass on my iPod to zone out to, and some soft-rock classics – “Eye of the Tiger”, “Highway to Hell” – though I was too knackered and bundled-up to punch the air. Tarka, weirdly, had barbershop quartets on his iPod. But mostly I found myself daydreaming about steak and burgers. I had a video loop of them in my head, swimming in grease.

So what’s the continuing allure?

At their best, expeditions are the purest form of escapism. It’s just you and the elements, and it’s a very simple life, if not always easy. Your existence is reduced to its essentials – walking, eating, sleeping. There are no texts or emails, you don’t have to worry about tax returns or getting the dog wormed. But the Antarctica trip was the culmination of a dream I’d been chasing my whole life, and it took me as far as I believe I can go; it’s taken me months to recover from it, physically and mentally.

Why?

I lost a lot of weight – I started the trip on 92kg and finished it at 70 – and I only averaged about five hours sleep a night. So by the end I felt like a zombie. And as soon as I came back I started stuffing my face and got really fat and ill, because my immune system was depressed. Mentally, I’m only just getting back on an even keel now, and finally savouring the achievement, nearly nine months down the line. I grossly underestimated how depleted I’d feel.

What’s next for you?

I have no more expeditions lined up and I feel as if I’m moving into a new phase. I’m writing a book about the Antarctica trip, and we’re also putting a film of the trip together from the footage we shot. There’s been some talk about starting an adventure foundation or perhaps facilitating other people’s travel to the Poles. I know I'll go back to those regions again because they’re a part of my soul now. I think real inspiration and growth only comes from adversity and challenge, and stepping out into the unknown. I’d say to anybody, just open the door a little. It’s a big world out there.

Self-belief is a really important ingredient in success. There’s nothing special about me; I'm not bionic and I don’t have a freakish lung capacity. I’ve just been extraordinarily stubborn. I think self-belief is like a muscle; the more risks you take and challenges you set yourself, the stronger that muscle gets.

I know I could lose everything tomorrow. I've been there many times, to the point of near bankruptcy, when I’ve had major sponsors pull out of backing me. There can be a weird liberation in having to start all over again from nothing.

At the Poles, I find a gorilla to be an essential accessory. Not a primate, but a Balaclava-type face mask with Velcro down the side. Obviously you look for performance in expedition gear, because a zip breaking or a bit of stitching coming undone is a very big deal at -45°C. When I’m giving speeches, I like to wear a really good suit. As with my life as a whole, my dress sense seems to be a matter of extremes.