If you’ve kept your finger on the pulse over the last few years, you’ll know that all of the hottest lifestyle trends tend to somehow originate in Scandinavia – from hygge and lagom to päntsdrunk (that’s having a drink at home in your underwear!).

Next up? We’ll all be turning to Iceland, to help whittle our bodies into strong, lean machines, with a buzzy training plan called The Viking Method.

It’s all outlined in a new book of the same name, by personal trainer Svava Sigbertsdottir, aka ‘Head Viking’.

Icelandic native Sigbertsdottir takes inspiration from her home nation, drawing on the tough mental and physical strength of vikings to create a Nordic fitness and diet plan that’s guaranteed to have you wincing with effort. As well as whipping mere mortals into shape, her clients include enviably-built celebrities like Nicole Scherzinger, Suki Waterhouse and Amanda Holden.

It’s not surprising we’ve directed our fitness attention to the island nation, when you consider that the Nordics are known as some of the strongest people in the world – Icelandic men have won the World’s Strongest Man competition more than any other nation, and you only have to conjure up images of vikings, with their rippling muscles and rugged beards, to get the picture.

Pride of Britain Awards 2017 – London
Nicole Scherzinger is said to be a fan of the method (Ian West/PA)

The slightly torturous Viking Method is all about functional training. It relies on repping through challenging movements, like burpees, squats, walking planks and bunny hops – exercises that don’t rely on expensive equipment and can be done from practically anywhere.

The idea is to focus on fatiguing the fast-twitch muscle fibres that are explosive, strong and powerful, creating a full-body workout that’s toning, strengthening and incredibly challenging.

Vikings train five times per week, and each workout takes around 40 minutes – including warm-up, cool-down and stretching.

The first thing to know about Sigbertsdottir is that she’s a straight-talking, no-nonsense coach, who won’t take any excuses.

"I started my method a few years ago, because I wanted to have a three-fold plan that would incorporate everything – the best exercises for your body, eating good fuel, and having the right mental attitude for fitness," she explains.

Sigbertsdottir believes it’s apathy and excuses that hold most of us back. "I’ve worked with so many people and I’ve found that it’s not that they don’t know what exercises to do, or what food to eat and not to eat, it’s more the mental side of things that they struggle with," she says.

"The Viking mentality is all about taking responsibility for your life. You put yourself in the driver’s seat – anything that’s happened up to this point is because of your actions.

"It’s about taking stock and accepting that you’re the reason why you haven’t exercised. It’s not because you don’t have time or it’s somebody else’s fault – it’s all on you, which means you also have the opportunity to change it. The method is also about having a bit of stamina when it comes to exercise too – so not giving up straight away because you failed the first time."

In this way, the Viking Method is as much about harnessing the right state of mind, as being a physical challenge. "Nothing is easy," writes Sigbertsdottir in her book. "If the last few reps or the last few seconds are not a complete struggle, you’re not working hard enough and you won’t see any change."

Although you don’t count calories like other plans, the Viking Method asks its participants to eat to fuel their training – making sure to get a right careful balance of macro and micronutrients. All of the recipes are inspired by Sigbertsdottir’s upbringing in Iceland, with dishes like Icelandic stew and Bifröst veg and rice.

Another key rule? Don’t weigh yourself. "Being obsessed with how much you weigh is a waste of your energy and says nothing about your progression," says Sigbertsdottir. "Throw out the scales."

Vikings are all about performance – teaching you to be tough enough to take on any physical challenge, whether that’s exercising outdoors when it’s drizzling with rain, or pushing through that last round of reps. The toned body that many of us strive for is just a byproduct of the physical gains.

"I get messages from girls who want to tone, lose weight, and look good, and they think, ‘Is this just a strength method?’. The answer is that it’s both. You focus on the strength and performance and the other results follow," says Sigbertsdottir.

It’s for this exact reason that she doesn’t do ‘before and after’ pictures. "It’s so easy to get upset with the ‘after’ picture, even if it’s good," she says. "You’re initially happy when you look at it, but after 10 minutes, you scan it for flaws and then you get unhappy again because you still see bits that you don’t like.

"It’s a slippery slope to constantly think about what your body looks like. Instead, I teach my clients to have goals like, ‘I’m going to be able to do 10 press-ups in a row’, and then it’s much less subjective – there’s no opinion in it.

"I often get asked how often you should train to look like Nicole Scherzigner," she adds with a laugh. "I tell people: ‘Well, no matter how hard I train, I’ll never be able to look like her, because she’s born with the smallest waist I’ve ever seen’.

"I have a straight waist and no matter what I do – unless I get massive bum implants or take some ribs out – I’m never going to have the same body. So if I base my body confidence on looking like somebody else, I’m going to be unhappy."

The Viking Method by Svava Sigbertsdottir is published by Penguin Life.