Fresh from staging elite padel's London debut, Kensington Olympia is this weekend hosting another fast-growing sport: Xenom.

Xenom has been dubbed "Hyrox for CrossFitters" – like Hyrox, it uses a set format designed to test many of the attributes honed through CrossFit and other functional fitness training. Its creators also describe it as the "decathlon of fitness" because of its 10 events, which include weightlifting, gymnastic and endurance challenges. The comparison reflects how Hyrox built a mass-participation model around a single standardised format – running and workout stations repeated identically at every event – which Xenom is now adapting for athletes with broader strength and gymnastics backgrounds.

The London event, running across Saturday and Sunday, drew more than 2,000 early registrations of interest and is only the second-ever Xenom competition, following the first in Dallas in June. It is open to participants of all levels, but some of England's most accomplished CrossFit athletes, including Sam Briggs and Kelly Friel, are set to compete. Briggs is a former CrossFit Games champion, underlining the calibre of athlete the new format has attracted in only its second outing.

Xenom is the brainchild of Keith Barlow, an avid functional fitness enthusiast whose PR work helped Hyrox grow to 1.6m participants globally. Barlow launched Xenom earlier this year with $15m (£11m) in funding from WNDR, a private equity firm established by Dreamworks co-founder Jeffrey Katzenberg and Sujit Jaswa, former chief financial officer of Dropbox.

"The functional fitness community in the UK and specifically London has exploded over the past decade, but there's been no consistent way to benchmark progress or compare performance across different competitions," said Barlow. "We're providing that standard – a repeatable test that athletes can use to track improvement season after season."

Xenom enters £6.5bn functional fitness industry

Barlow believes there is "a really compelling case for investors looking at this space", citing parallels not only with the indoor functional fitness race Hyrox but also with Ironman triathlon.

"When you look at the value placed on successful IP-led events business, you can see that a long-term vision and the ability to deploy capital smartly and tap into consumers who are deeply passionate about their sport are highly valued across the market. We represent that same opportunity in our space," Barlow added. The comparison points to the track record of IP-led endurance brands: Ironman, acquired by a Chinese conglomerate in 2015 and later rebranded as the Ironman Group, demonstrated how a proprietary race format can sustain a global events business spanning triathlon and running.

London is firmly established as one of the world's leading locations for both mainstream and minority sports. As well as padel, the capital this year staged the first event of the Pro Climbing League and last year hosted the world's biggest Hyrox event at the ExCel.

The functional fitness industry has grown rapidly in recent years and was valued at £6.5bn in 2025. Xenom enters that market at a time when Hyrox's rapid expansion has shown the appetite for mass-participation functional fitness racing, while CrossFit's own competitive season has long centred on its flagship Games, leaving room for standardised, multi-discipline formats athletes can enter at any stage of their development.

After London, Xenom has another competition scheduled for December in Miami. Next year it hopes to stage 8-10 events, beginning with Malaga and Paris. Delivering that schedule would move the venture from a two-event startup toward the consistent calendar that Barlow argues is the key to building benchmark value for athletes.

"We see an incredible opportunity to build a global competition which reenergises and meets the huge unmet demand from people training in boxes, garages, and gyms around the world," Barlow said. "We will allow our competitors to compete on the world's biggest stages and demonstrate the incredible physical capacity they have built in the gyms for their friends, family and peers to see.

"Xenom will be the defining cultural platform for high performance and the pursuit of elite fitness."