Who on earth wants to work out in the middle of the night? We visit one of the growing number of 24-hour gyms to find out

Well, this is odd. I'm in the gym – The Gym in Vauxhall, south London, to be precise – and Michaeljohn Gonzalez is pumping iron. Nothing strange about that, you might think. This is, after all, a gymnasium. It's just the time of day that is a bit weird: it is 4am.

Weirder still, Gonzalez is not alone. On the treadmill runs bouncer Ahmed Mohammed. Next to him, Alan Dyer, a restaurant manager, works out on the pec machine. And upstairs Jakob Grzebeniak, a blue-haired rickshaw-driver, practises his boxing.

Britain has had 24-hour gyms for at least a decade but in recent months they have become exponentially more popular. A year ago, The Gym Group owned 10 all-night gyms. Now it has 18, including this one, and there are plans for a further 17. This time last year, Pure Gyms – another national 24-hour chain – ran just 12 outlets. By 2013, that will rise to 45. One in five Pure Gym users work out overnight; 15% use The Gym between 10pm and 6am. What's the appeal? I am spending the night here to find out.

Most clubs close at 10pm, but when I arrive at 11, The Gym is still packed with around 70 runners and weightlifters. Thirty-eight-year-old security guard Kevin Jey – who comes here twice a day, six days a week, for five hours a time – is one of them. Why? "It's so much cheaper than other gyms," says Jey, and he should know: he claims to have been to 50. "My last gym cost £45 to £50 a month, the one before was £95." By contrast, the monthly cost of The Gym is just £15.99. Pure Gym costs only two pounds more.

"You don't feel like someone's robbing you," says 24-year-old Melody, pedalling a bicycle at midnight. The changing rooms have just closed for cleaning, there are only 30 people left – and that's the appeal, she says: "I get to use the machines I want to."

Given the price, the range of equipment is impressive. There is no pool or sauna – but there are 30 treadmills, 30 bikes and 12 rowing machines, not to mention all the weights. That is twice as much as my last gym, where fees were double what they are here. The Gym is bigger and lighter, too. "A lot of other gyms are underground," says Giovanni Genovese, a former sociologist and now the gym's assistant manager. "At my last job, I used to arrive at seven and not see daylight all day. So when I came here, I joked: 'I saw the light.' It makes a difference; you feel happy."

By 2am, the headcount is down to 15. Only one woman remains: 19-year-old Demmi Russell, who comes at night because she's at college during the day, then works at a betting shop until 10pm. She likes it here because she feels safe. "As a woman, it's hard to find a gym where you feel comfortable," she says. "But if you come here at three in the morning, no one's going to bother you."

Forty minutes later, the gym is all but deserted. There's just me, Genovese, the cleaner and two fitness fanatics who don't want to talk. But at 2:45, in strolls Marco, a 28-year-old travel agent, closely followed by Jonelle Roberts, 24. They are here for different reasons – Marco is an insomniac, while Roberts was on the late shift at Selfridge's – but they had similar motivations for joining. "There's no contract, so you can quit when you want," says Roberts, in the middle of 300 sit-ups. "There might be a time when I can't come to the gym, so it's great that I can just put my membership on hold." In fact, that is something Marco has already tried.

Contractless gym-going is not a luxury afforded to members of many other chains. LA Fitness made headlines last week for failing to release from their contract a couple who had fallen on hard times. But such a situation is anathema to John Treharne, who founded The Gym in 2008 after being inspired by a 24/7 gym culture in the US and Germany. "I have never believed in membership contracts," he says. "There is no commercial need for them. Not having them actually widens your commercial appeal."

So how does The Gym make money if it never closes, doesn't hand out contracts and its branches are bigger and better stocked than its rivals? Because administration costs are much lower, says Treharne. When you sign up, you don't have to complete any paper forms – you just fill in your details online and within minutes you can begin exercising. "Other chains might have a membership officer at each branch, and six to eight at head office. We don't have any."

Back in Vauxhall, it's 5am, the changing rooms have re-opened, and there are now a dozen men on the gym floor. People with something approaching a normal sleeping pattern have even started to arrive. But a few of the old guard remain. There's Daniel Williams, who got up at three to make the most of the empty weights room. He'll go back to bed again once he has finished.

And there's Gonzalez, an acting coach who works LA hours, tutoring Hollywood starlets via Skype. He lives in the building above the gym. That's convenient, I say. Convenient? He laughs: "The gym is why I moved here."

{loadposition user38} source: http://www.guardian.co.uk/lifeandstyle/2012/jan/29/exercise-in-all-night-gym

source: http://www.europerank.com/lifestyle/lifestyle/59363-hard-at-it-all-night