Bruce Parry: Just another day in Siberia ...

In Tribe, some viewers may think I put myself in difficult, dangerous or even hostile situations. But one of the points of the programme is to show that for the indigenous people who live in a place, their environment is completely normal. Really normal.

I think living with the Nenets people in Siberia was probably the hardest trip of the series because the physicality of the day-to-day routine was extraordinarily tough, even for me. On screen, and on the face of it, life appears unforgiving – all about survival. But for the Nenets who live there, it's just ordinary daily life. And that's the same whether it's a tribe living in the Arctic, the desert or the jungle. Like when the Kombai people in West Papua were pointing their bows and arrows at me when I arrived. I knew it wasn't dangerous because they knew I was coming. I instinctively felt, that for them, it was part of their ritual.

Siberia was one of the most extraordinary places I've ever visited. I'd been to the Arctic many times before but this was something else. During the first three days of being in the Yamal peninsula in western Siberia with the Nenets I must have pinched myself on at least three occasions. I thought: "Oh my God, I've never seen anything in my life remotely approaching this before." The landscape was the most spectacular I'd ever seen.

I flew in by helicopter to meet the Nenets who live in groups of about 60 people called brigades. The brigade I visited lived in eight chums (pronounced choom), which are like tepees, and they travel nearly every other day, following their reindeer as they migrate north or south. The reindeer eat lichen, which grows very slowly and only in pure environments, so they have to keep eating and moving on in search of more.

On the first morning, I woke as the sun was very slowly beginning to rise to find more than 7,000 reindeer, and their massive antlers, backlit against the horizon. That was awesome. Because of the latitude, the sun takes hours to break the horizon and then hours to set. The result? Hour after hour of scarlet skies that mix into sunset in what seems like no time at all. Imagine the crimson glow on the reindeer and the chums with smoke billowing out of the top. Totally blinding.

The Nenets then lassoed some of the reindeer and tied them to 300 sledges. Next, we travelled in a long, long line. As I looked over my shoulder I could see about six miles of sled behind me being pulled by the huge-antlered reindeer. Could life get any more gripping? I was freezing cold even though I was wearing a big fur suit as temperatures can plummet to -50C. I thought: "No one has ever seen anything like this." The sweat on the backs of the deer froze and crystallised. It caught the slight breeze and fell on the snow like small particles of ice dust falling in slow motion. It was like the frozen equivalent of a Western wagon train and its dust clouds.

Life is arduous for the Nenets. It takes them at least four hours to take down the chums and pack them up on the sleds. And it takes about 30 sleds to carry each chum. They don't use the same reindeer every day, identifying them by their antlers and coats. Every knot of the reindeer harnessing has to be tied up individually, so you have to get your fingers out in freezing conditions. Travelling to their destination takes a few hours, and then unpacking everything and erecting the chums again a further four hours. So it's a very long day and totally knackering.

Your first reaction is to think: "Why do they choose this? They could easily live in a house with central heating." But that's to look at the Nenets from a slightly arrogant point of view: our preconception is that our way of life is better. What we don't realise is that the Nenets choose to live like this – in the post-Soviet era most of them have boarded at school. My host had worked as a university lecturer and travelled around the world. But he'd given all of that up to get back to his roots and be a reindeer herder, not only because he earned more money doing that, but also he found living in town a prison sentence. To him this was freedom. Where else in the world can you get up everyday and take your entire livelihood with you?

The reindeer provide the Nenets with their shelter, transport and nourishment, and their lives revolve around following the herd. They see themselves as free, unlike their fellow countrymen who live in big towns that have been fuelled by the discovery of gas there. It's only because the Nenets inhabit a remote, desolate part of Siberia that no one else wants to live in that they have been able to travel up and down the peninsula and nobody has got in their way. All the other nomadic peoples of the world who once enjoyed complete freedom have had their land slowly taken away from them.

The stories we try to tell in Tribe involve getting away from our preconceptions and overcoming stereotypes. In the final scenes in the film about the Nenets, I go with them to their houses in town, which they visit for a couple of days each year. They said to me: "Like, yeah, we've got TV and cook on a gas stove and have houses, but so what? We hate it here." So how dare we go in and suggest that our way of way of life is the better one?

To do the things I get up to in the Tribe series you have to be quite fit but I'm no different from anyone else in the street. I was lucky because I was a Marine so keeping physically fit has always been part of my regime. That gives me a resistance to harsh environments. And, by a happy coincidence, I've been on a long spiritual journey throughout my life, always challenging my preconceptions. This started when I was very young, being institutionalised with a nationalistic view of the world. It's taken me a long time to get to where I am now, trying to see everything at face value rather than stepping into a situation with my own judgement before I've really explored it.

I continued on this journey when we visited the Layap people. These wonderful Bhutanese Buddhists, predominantly dark-haired, live at about 4,000m in the Himalayas. They are polygamists – some of the women have more than one husband and from my very limited understanding, because I didn't explore the subject, it seemed to be an arrangement that really suited their day-to-day routines. One husband would be up on the higher ground with the yaks while the other would be down in the community helping out with the farmland.

One of the Layap people who really touched me was a guy called Kencho. He had this great sense of joie de vivre and was a very free and easy person. He was a Gonchen, which is like a lay leader of a large district community of Buddhists. Kencho had been trained as a monk, so he could explain the rudimentary elements of the Tibetan variety of Buddhism that the Layap people follow.

One day he sat me down and made a big circle of white grains of rice on a scarlet cloth. He told me that this represented the Wheel of Existence. Next he laid down six little piles of rice and said: "Each pile of rice represents the different realms. If you do good deeds in life you'll be born in heaven as a god, a demigod or on earth as a human. If you do bad deeds, you'll be born as an animal, a demon or a hungry ghost."

Our ultimate destination was to have been a rarely visited place called Lunana, which we never made it to, because the yaks couldn't get over the high pass. I could have probably got there if I'd been on my own, but that's one of the ironies of the programme: because although it looks like I'm on my own on camera, in reality I have a film crew with me, who need to be fed and have all their heavy gear carried.

It didn't matter because the lessons we learned from the Layap people about Buddhism and the Four Noble Truths and about dharma and karma were really interesting. And that's the point of Tribe – to show a greater understanding of these people who have been cut off from the rest of society and to learn from their experiences.

Further reading and viewing: 'Tribe' by Bruce Parry, is published this week by Michael Joseph, price £20. 'Tribe' concludes on BBC2 at 9pm this Tuesday