11/03/2014 09:40 GMT | Updated 09/05/2014 06:59 BST

The Day I Tried Viking Fitness Class

Spring has always been a popular time to take up new exercise routines to ward off the post-Christmas barrel belly. But many of these routines are stale and mundane, and people tend to give them up after a few weeks...

Spring has always been a popular time to take up new exercise routines to ward off the post-Christmas barrel belly. But many of these routines are stale and mundane, and people tend to give them up after a few weeks.

"People often throw up the first time they come here. It's not always that easy to get into," says John, a medical student and a regular at Vikings and Valkyries, a fitness class inspired by our Nordic ancestors.

I am standing in the middle of a five a side football pitch hidden underneath some railway arches in Shoreditch. I'm surrounded by a selection of unusual fitness challenges. This is by far the most bizarre looking gym circuit I have ever seen. No machines are in sight. The first items that catch my eye are tractor tyres, mallet hammers and several large metal kegs.

Vikings & Valkyries, the brainchild of fitness trainers James Langley and Eddie Baruta, is proving to be a hit with Londoners. The fitness program has shown to be effective for its clients, who seem to love the variety of the exercises.

The attendees don't look like Vikings, mind you. Most of them are well-groomed professionals in need of an evening fitness fix. "I lost almost 6kg from attending once a week for eight weeks. Not bad for a woman in her fifties," says one client, who has come to the club after work. Jack, a keen runner, claimed that the routine had improved his half marathon time by almost ten minutes. It was time for me to find out what all of the fuss was about.

The fitness circuit consists of nine stations that are all worryingly close to each other. First up is the barrel lift. We have several rounds of thirty seconds to lift the metal barrel directly over our heads as many times as safely possible. I only manage to do this about three times. Even after one lift, my arms succumb to the pressure and feel jellified. I can barely trust myself to be able to lift the barrel without dropping it on the person doing the "Bear crawl" a metre in front of me. Fortunately, my trainer Justin was close at hand, ensuring that this was not going to happen.

Two minutes later and I am now the bear. I crawl the whole length of the five-a-side football pitch with my stomach flat on the floor. From above, it had looked easy and not too strenuous. At ground level, it is a different story - the astroturf burns harshly on my knees and progress is slow. It gets much slower after a couple of lengths of the pitch. Did Vikings crawl about to lose weight after having too much fatty lamb broth?

John, who is my partner around the circuit, is also struggling to get used to this harrowing routine. The pain really hits home when we begin the "Squat war" - which involves locking arms with your partner and taking it in turns to pull as hard as you can against them, without moving your legs. Not only did it prove to be a fantastic workout for my arms, but also it nearly snapped my calf muscles. John was much bigger than me.

After my arms went through an ordeal, I am asked to hold a vertical handstand for half a minute, several times. My head feels faint and I start seeing red. But the show must go on. A glug of water and I'm on to the "Dumbbell renegade row". I am struggling to hold myself in the press up position while taking it in turns to hold each arm up with a dumbbell in it. It was a great workout for my abdominals and upper back, but that was the last thing on my mind at the time.

The most challenging exercise in the nine-station circuit is the "Prowler push" - a huge metal frame with 40kg weights attached to it that you push the whole length of the pitch in two different positions. It is not long before I feel as though I've hit a wall.

Several burpees later and I'm feeling completely broken. I wield a sledgehammer and smash it continuously against a tractor tyre, whilst my partner is frantically pulling on ropes attached to a heavy keg. As well as providing a sound workout, pulling hard on the "Battle ropes" and ruthlessly smashing up a tyre with a sledgehammer is a good way to vent any midweek aggression.

After completing the circuit two times over, everyone then engages in a massive tug of war. Hard techno bass lines throb in the background as I pull back as hard as I can. Before I know it, I've moved forward four metres against my own will. My hands look like butchery. The 45 minutes of madness has come to an end.

As I hobble back onto the tube, I struggle to make sense of what just happened. I didn't feel like a Viking earlier this evening, but I certainly feel like I've been beaten up by a few now.