'The endorphins are off the chart': How London became obsessed with HYROX

An Australian athlete who soiled herself during a HYROX race and continued to the finish has become an unlikely symbol of how far competitors are prepared to push themselves.

Joanna Wietrzyk, a women’s world-record holder, suffered sudden bowel incontinence during a competition in Beijing in September.

She carried on using shared equipment and initially won the race. After footage spread online, she apologised and withdrew from the result.

HYROX admitted officials should have intervened and changed its rules to allow athletes to be removed if bodily fluids pose a welfare or contamination risk. Wietrzyk returned to competition last weekend, winning in Hamburg.

The extraordinary episode raises a question as the fitness phenomenon attracts record numbers: how far should you push your body in pursuit of a finish time?

It is particularly timely in London, where the next Amazon HYROX event takes place at ExCeL from December 2 to 6, with races scheduled for December 5.

The next Amazon HYROX event takes place at ExCeL from December 2 to 6

Hyrox

Part fitness competition, part endurance challenge, HYROX is a standardised indoor race combining eight one-kilometre runs with eight workout stations.

Competitors tackle sled pushes and pulls, burpee broad jumps, rowing, farmer’s carries, sandbag lunges and wall balls. Open, Pro and Doubles divisions allow individual and partner entries.

Why has HYROX become so popular?

According to HYROX, participation rose from 650,000 athletes in the 2024/25 season to 1.5 million in 2025/26, an increase of more than 130 per cent.

The organisation expects the figure to pass two million this season.

Organisers received 66,000 applications for 15,000 places within 24 hours for the London HYROX event

AFP/Getty

Demand for its London event has surged, too. Organisers received 66,000 applications for 15,000 places within 24 hours, prompting the introduction of a marathon-style ballot.

For Lucy Davis, a hybrid athlete and founder of women’s sportswear AESENE, the appeal lies in the balance between an intimidating challenge and an accessible format.

Davis is a Hyrox world record holder and Founder of premium sportswear brand AESENE

Lucy Davis

She told the London Standard: “You don’t have to learn loads of complicated technical movements.

“Most people can understand running, pushing a sled, lunging, rowing or doing wall balls.

“You can look at the race and think, ‘that looks horrific… but I reckon I could do it!’”

When does pushing yourself become too much?

The pressure to improve times and enter more competitions raises questions about overtraining.

Davis says there’s a “difference” between embracing discomfort and ignoring warning signs

Lucy Davis

Davis, who has spent time away from competition following knee surgery, says there is a difference between embracing discomfort and ignoring warning signs.

She said: “I'm a huge believer in doing hard things. Some of the best moments in my life have come from pushing myself beyond what I thought I was capable of.

“But being tough doesn't mean ignoring your body.

“I think the biggest thing is looking for patterns rather than panicking over one bad session.

Davis believes social media has made competitive fitness feel "much more accessible".

Lucy Davis

“Everyone has days where they feel tired or their training isn’t great.”

Davis adds that persistent pain or unusual weakness should be assessed by a qualified professional.

“Sometimes taking a step back is exactly what allows you to take a much bigger step forward,” she added.

Tom Porter, a personal trainer who has completed 13 races in different countries since his first in February 2025, says the standardised format of a HYROX makes it addictive.

Porter has completed 13 HYROX races in 13 different countries

Tom Porter

He explained: “It's the same wherever you go. You do it, you get a time, and then you want to go again because you want to beat it.

“There's probably an over-focus on high-intensity training. It's important, but you can't train like that all week.

“You need to put just as much focus on the easier days, whether that's slower runs or sessions where you're using lighter weights and concentrating more on technique, rather than running as fast as you can or lifting as heavy as you can every day.

“It's not sustainable, so you need a mixture of both.”

From weight loss to a whole new lifestyle

For Aidan Boyle, a father of two, HYROX began with a simpler motivation.

Boyle started exercising after realising his jeans no longer fitted

Aidan Boyle

He had never heard of the sport before January 2026, but started exercising after realising his jeans no longer fitted around his son’s first birthday.

“I started off wanting to lose weight, and that was it,” he told the London Standard.

Since working with Porter, Aidan has competed in Tenerife and is preparing for races in Dublin and London, alongside taking on a half Ironman.

Personal trainer Tom flew out to see Aidan compete in the Tenerife HYROX

Aidan Boyle

He told the London Standard: “It completely wipes your body out, but afterwards your endorphins are through the roof. It's a weird buzz.

“What starts as wanting to lose weight ends up changing your whole life and your mindset. I feel like it's chilled me out as well.”

Porter has also witnessed the impact on Aidan's family, with his wife Tilly becoming more involved in fitness and their children growing up watching exercise become part of everyday life.

Aidan will be taking part in the London HYROX on December 5

Aidan Boyle

Porter added: “Aidan is a perfect example of someone that's completely given everything, and he really listens to advice.

“He wants to learn more. He asks questions.

“He then takes that away and improves himself and does the work himself as well.”

Do you have to be fit to start HYROX?

For beginners, personal trainer Tom Porter advises building up gradually and combining running with practice at the workout stations.

Tom Porter helps members of the public achieve their fitness goals by following his training

Tom Porter

He said: “A good example of this is my mum. We did one [HYROX] together in Glasgow earlier this year, which she used as a bit of a lifestyle change.

“She's 62 and, before that, wasn't really able to run 1km without stopping to walk.

“Within four or five months, she was able to run up to 10km without stopping.”

As HYROX returns to London in December, the challenge is attracting people for reasons beyond a medal or personal best.

Tom Porter

But Wietrzyk’s experience is a reminder that pushing yourself should never come at the expense of your health or the safety of others.

For those still considering signing up, Lucy Davis has a simple message: “Do it scared! You don’t need to wait until you’re fitter, stronger or more confident.

“I always say, confidence normally comes after you do the thing that scares you, not before.”