Sweat drips from the foreheads of 12 flushed City workers as they crunch their way through burpees and 750-metre treadmill runs before hurling “wall balls” — heavy balls that are thrown at a target at least nine feet off the ground.

Welcome to the lunchtime workout at the Gym Group in Monument, near London Bridge. The dozen participants straining their muscles to high-tempo techno music are part of the fitness craze that is Hyrox, a business that combines races with strength-training events and workout classes.

Alex Drewe, a 27-year-old patent lawyer who is a Hyrox pro athlete in her spare time, said: “It’s a really good release because a lot of my job is quite high pressure.” She loves the fitness challenges because it “is quite demanding — you can’t really think about anything else so you just lose what’s on your mind”.

Hyrox was founded in 2017 in Hamburg but now has a presence in 30 countries. It has forged partnerships with sportswear companies, energy drinks and fitness supplements. Last year the company hosted 74 races and will hold 105 this year.

In addition, it has teamed up with gyms to offer Hyrox-branded fitness classes led by local instructors. Women made up 57 per cent of its participants in the UK last year.

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January is naturally a peak time for fitness enthusiasts to hit the gym, but Hyrox’s appeal is year-round. Its co-founder, Christian Töetzke, who has a background in organising endurance events such as Ironman triathons, felt it was important for gym-goers to have reasons to train aside from “burning calories and aesthetics”. He designed the brand with his business partner, Moritz Fürste, to remedy this.

Christian Toetzke, Co-Founder of Hyrox, smiling.

Christian Töetzke says Hyrox is about much more than “burning calories”

HYROX/CHRISTOPH STEINWEG

“We had a lot of principles when we created Hyrox. One was, it’s accessible, everyone can do it … though it’s very hard; the other principle was we wanted to create the healthiest sport … that has longevity,” Töetzke said.

At Hyrox events, participants run eight kilometres around a track in one kilometre intervals, broken up by fitness exercises such as sled pushes, burpee broad jumps and rowing. In training classes, athletes usually run on treadmills.

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There are five categories of races for the non-pro or elite competitors: singles, mixed doubles, women’s doubles, men’s doubles and relay.

Two years after it was founded, Hyrox attracted investment from Swiss sports marketing company Infront, owned by the China-based Wanda Group. Infront became the sole investor in the company in 2022.

A group of female athletes in black sports bras and shorts competing in the HYROX Elite 15 race.

Hyrox’s 8km races — in places such as Amsterdam and, below, Hong Kong — are hot tickets

JOERG MITTER/RED BULL CONTENT POOL

Joanna Wietrzyk pushing a weighted sled during the Elite 15 at the Hyrox Major in Hong Kong.

BRIAN CHING SEE WING/RED BULL CONTENT POOL

It is estimated that Hyrox turned over £84 million last year, but the company does not disclose financial information.

The business has a number of revenue streams, of which by far the biggest is entry fees to its events, which make up about 90 per cent of its turnover. It also makes money from partnerships with brands such as Red Bull and Myprotein — by selling Hryox-branded products — and from sales of food and drinks at events.

Further revenue comes from Hyrox’s deals with gyms. For a fee of about £100 a month, gyms can become “Hyrox affiliated”, meaning that they gain access to presale tickets for events and training programmes, and have the right to use the name and promote sessions as Hyrox classes. There are more than 5,000 Hyrox-affiliated gyms globally, of which about 1,500 are in the UK.

While Hyrox incurs costs for the staff who run its events, race judges work free, although they are given benefits such as guaranteed entry to races, which to some Hyrox junkies may be more valuable.

Indeed, securing tickets to a Hyrox event is almost a competitive sport in itself. One recent event had a digital “queue” of 25,000 people logging on to grab tickets when they went on sale. Small wonder that one customer, Oliver Knight, 27 said: “It seems to be just as hard getting Hyrox tickets as it is getting Glastonbury tickets.”

Last December, Hyrox hosted its biggest and most-popular racing event to date in London, attracting about 40,000 athletes and 30,000 spectators to the four-day extravaganza — a near-6,000 per cent increase from the 650 athletes who took place in the first race in London 2021.

Much of the brand’s rapid growth is down to its success on social media. Hyrox has found a receptive audience among the fitness-obsessed Generation Z, some of whom treat marathon times like status symbols.

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Töetzke said the speed at which the business grew “wouldn’t have been possible 20 years ago without these social media platforms”.

Olivia Smith, 24, who works at a wealth management firm, said she got into the sport after seeing people such as the fitness influencer Zoe Rae, a Hyrox pro athlete who is sponsored by Myprotein, compete on Instagram.

“Zoe Rae was one of my biggest inspirations … she started posting quite heavily,” said Smith.

Zoe Rae and Aine Woodman celebrate with their finish time of 1:06:39 at a Hyrox event.

Zoe Rae, left, at a Hyrox event with her friend Aine Woodman

INSTAGRAM/@ZOERAE

The rapid growth of the brand has not been without controversy. After the recent London event, some angry racers took to social media to condemn the queues at the wall ball station, the last fitness station on the 8km route before the finish line.

Töetzke said it was “completely unacceptable” but the queue affected only about 40 – 50 athletes out of 40,000.

Hyrox is now selling tickets to a week-long cruise around the Mediterranean, with the aim of being the world’s largest floating gym.

After the class in Monument last week, Charlene Munson, 38, described the curious appeal of Hyrox. During her first race, she was thinking, “Why am I doing this? What is this?

“And then afterwards, I’ve never felt a buzz like it in my life.”