Will Orr

The head of the lowcost fitness chain tells Julia Kollewe it is riding a wave of gen Z growth as young people embrace exercise as being beneficial for both mind and body

- Julia Kollewe

If you have friends, chances are you'll have seen at least one posting online about a Hyrox race, the gruelling competitive circuit-training trend health-conscious that has swept the fitness sector.

Will Orr knows a thing or two about it. His company, The Gym Group, has rolled out Hyrox training sessions to about half of its 245 sites and prides itself on being the biggest club for the discipline in the UK.

However, the silver-haired chief executive has a confession to make: he has never done a Hyrox competitive event, although he has done some training.

"They're quite demanding; that's not to say I couldn't do it," he tells the Observer as we meet in the no-frills gym chain's new site in Elephant and Castle, south London.

"I'm old-school - I go on the treadmill and the rowing machines." Hyrox is certainly not for the out of shape: participants have to perform eight 1km runs on a treadmill, each followed by a workout on a different station, such as the sled, sandbag lunge or wall ball.

Launched in Germany eight years ago and touted as the sport for everybody, it has become particularly popular with twentysomethings, who post social media snaps of themselves training for races held around the world. Christian Yanga, the Elephant and Castle gym manager, says their oldest member doing Hyrox is 75, while the youngest is 16.

The craze is just one leg of a strategy has helped The Gym Group become one of the biggest players in the fitness sector. Founded in 2007 by the former England squash player, John Treharne, as Britain's first budget, 24-hour gym chain, it has since grown to 951,000 members, with plans to open 50 more gyms in the next three years.