James used to start his Saturdays at noon in the pub with mates and stay until 3AM, drinking – he half-jokes – ten pints over the course of the night. Since October, though, he hasn’t had a drink. He hardly goes to the pub anymore and now follows a vegan diet.

“It’s been a drastic turnaround,” he says, labelling it a part of his life that has “changed 100 percent”. The reason for this dramatic shift? About five months ago, a friend invited James along to an indoor climbing wall in north Tyneside where he lives. James hadn’t done sports “for god knows how long” but enjoyed watching Free Solo, the 2018 documentary tracking Californian rock climber Alex Honnold’s ropeless ascent of a 900-metre rock face in Yosemite National Park. He thought he’d give it a go. “Since then, it’s been something that I’ve kind of completely been obsessed with,” he says.

Soon after this first session, James was going to the climbing gym three or four times a week. “It’s not only the physical aspect of it but the brain work that you do with it, in terms of reading routes beforehand,” he explains. “It’s also really good for setting goals in a friendly competition with the people you’re with.”

James isn’t alone in his newfound obsession. For the past two years, climbing has been enjoying a boom in popularity. In 2018, the Guardian declared that the sport had gone from niche activity to “worldwide sensation”, with users of indoor climbing centres growing by as much as 20 percent each year. Last year, The Cut asked, “Why is everyone I know bouldering all of a sudden?”, citing Zac Efron and Brie Larson as celebrity fans of the sport. The success of Free Solo and other high-octane climbing docs – including The Dawn Wall, which sees climber Tommy Caldwell fight off terrorist kidnappers and lose a finger, all before completing a world first in free climbing – have also helped bring climbing to a mainstream audience. Sit back and chart its transformation from outdoorsy pastime for nerds in Mountain Warehouse fleeces to hobby du jour.

“A few years back at house parties, I used to just absent-mindedly bore everybody by talking about climbing,” says Pez, who lives in London and has been climbing for more than eight years. “But now, you mention that and the person whose eyes would have glazed over before pipes up, talking about The Dawn Wall.”

Brett Ffitch of The Climbing Nomads tackles an outdoor bouldering route. Photo courtesy The Climbing Nomads

While women are well represented in professional climbing (bouldering World Cup champ Shauna Coxsey competes for Team GB when the sport makes its debut at the Tokyo Summer Olympics), as a hobby, it seems to hold particular allure for millennial men. You probably know at least one guy, in his late twenties or early thirties, who will not stop talking about the sick overhang he did at The Castle last weekend. He turns up to the pub in a Patagonia Triolet jacket, follows a select few Californian climbing bros on Instagram and has intimate knowledge of the Joshua Tree mountains, despite living in New Cross. He just spent 100 quid on a pair of La Sportiva climbing shoes. Oh, and he has biceps now. Please meet: the climbing guy.

Brett Ffitch and Sophie Cheng are UK-based mountaineering instructors who teach outdoor climbing here and in Europe, as well as running the Climbing Nomads YouTube channel. In the past few years, they tell me that they have seen an increase in indoor climbers attending their sessions.

“A lot of courses that we run are taking people who have learned to climb indoors and want to apply those skills outdoors,” says Ffitch. “It’s definitely the trend now that everyone starts indoors and learns the very basic skills and then goes outside.”

Indoor bouldering, which involves scaling a wall no more than a couple of metres high using colour-coded plastic holds, is the type of climbing that James and most city-dwelling climbing guys do. Unlike top rope or lead climbing, it doesn’t require ropes or harnesses, so can be undertaken fairly easily – you just show up at your local wall, rent some shoes and get started on a beginners’ route. According to the Association of British Climbing Walls, an estimated 1.5 million people visited an indoor wall in 2018, while the London Climbing Guide website lists more than 20 walls in London alone. “It’s just more accessible for them,” Cheng says. “They can do bouldering at a climbing centre, rather than getting in a car and driving somewhere.”

James at Climb Valley indoor bouldering wall in Newcastle. Photo courtesy Daniel McGrath.

Adam, who lives in London, first went to an indoor climbing gym about six months ago, after a break-up. “I had this image of loads of nerds in an enclosed space making tiny movements on these little bits of plastic stuck onto walls,” he says. “I thought it would be really easy. It turned out to be a challenge, both physically and mentally.”

He was soon hooked – thanks in part to how easily he could start – and now climbs regularly at indoor bouldering walls across London, including Arch Climbing Wall in Bermondsey and Mile End Climbing Wall.

London-based Robin also got into indoor bouldering through friends and quickly adopted it as his own hobby. “After about three to six months, I bought some shoes,” he says. “I started going more regularly, realised I really liked it, and now I get up at 5.45AM to climb at 6.30AM, two or three times a week.”

Like cycling or cast iron pans, climbing offers men an opportunity to geek out about equipment and technique – Robin compares it to doing “an interactive 3D puzzle with your body.” The r/climbing subreddit overflows with advice on how to prevent climber’s elbow, and dizzying selfies posted by climbers after “sending” a route (AKA completing a route without falling or stopping to rest). Popular climbing vloggers like Magnus Midtbø, a former competitive climber from Norway, post training advice videos to hundreds of thousands of subscribers.

“You get completely obsessed with everything around it,” says James, who watches climbing videos when he’s not at the climbing gym. “It’s bizarre; it’s a very nerdy aspect of my life at the moment. Something I’ve been boring my family and friends with.”

Scrambling up a wall also has the added benefit of being exercise without feeling like exercise. Which, if you’re a twenty-something lad who used to play football before he fucked up his hamstring and doesn’t fancy taking up running, is ideal.

“It’s very interesting when you look at different male climbers,” says Pez. “The presumption might be, ‘The guy with the biggest guns is going to be the best climber.’ But actually that’s not always the case. If you’re doing an overhang, then you need a lot of back muscle and chest muscle but you also just need to be very delicate on your feet. The presumptions of what makes a ‘powerful male’ kind of get overturned in climbing.”

However, climbing’s appeal among millennial men goes beyond exercising mind and body. Unlike regular gyms or team sports, it has a strong social element. You can spend lots of recovery time on the crash mats between climbs, opening up opportunities to start conversation – both with friends and strangers. “Climbing naturally lends itself to being a very chatty sport,” Pez says. “There’s a lot of sitting there, thinking about what you’ve just done. If you’re both trying the same route and you’re strangers, and you’re both making the same mistakes, then you’ve got a reason to start speaking to someone new.”

Robin agrees: “I’ve gone to the gym loads in the past and I’ve just stopped now. I’ve realised that I just go to the gym, lift some weights and don't talk to anyone. Whereas if I go climbing, I get to have a bunch of people that I’ll meet up with and they cheer me on.”

Much has been written about the difficulties men have in maintaining friendships in their twenties, whether due to long working hours or a lack of awareness about their own emotional needs. A 2015 YouGov poll found that 12 percent of men over the age of 18 didn't have a close friend they would discuss a serious life problem with. Climbing, with its space for conversation and the excuse it provides to meet up with a group of people every week, provides a valuable antidote to this.

Robin says: “For a large chunk of my twenties, I lived with six of my closest friends and now we’re nearing 30, that’s stopped. It’s been very difficult to see a group of friends three times a week – like, that just doesn’t happen. With climbing, it’s an excuse to see people because you’re exercising as well as it being this really fun thing.”

“For me,” Adam says, “the big thing was finding something sociable that doesn’t involve booze.”

All the climbers I speak to are aware of the “climbing guy” stereotype (“Somebody who’s taken their top off unnecessarily at the climbing wall,” Pez says; Robin notes that many climbers work in tech: “They’ll be the people wandering around with a Dropbox t-shirt”) but it doesn’t bother them too much. None climb to emulate the daredevil antics of Alex Honnold, nor for the excuse to buy an Arc'teryx Proton hoodie. Getting together with mates and challenging yourself – mentally and physically – is the biggest driver. And yes, they’re aware of how earnestly wholesome that sounds.