Welcome to CrossFit Asphodel, a boot-camp-styled gym that specialises in competitive group training. In recent years, turbo-charged fitness regimes like CrossFit have become increasingly popular among hedge fund managers, bankers and traders. They are drawn to the intensity of the workouts and their emphasis on quantifiable results.

'There's an inner part of people which can be quite competitive: that may tell you why there's finance people here,' says Alix James, director of CrossFit Asphodel. 'In a year we've gone from two members to over 100. It's just been word of mouth.'

A Muay Thai boxing coach, James opened the gym in December 2010 with his partner Ashley Booth after discovering the online exercise programme CrossFit.

Founded by a former gymnast in the United States, CrossFit is a set of strength and conditioning exercises that have developed a cult following worldwide. The programme is so aggressive that it is used by police academies and the US Navy.

'After some workouts everyone is on the ground dead,' confesses Tiffany Yancey, a personal trainer who attends 6am sessions.

'You go in there and it's very different to seeing cable machines and your typical gym equipment,' says Todd Themistocles, of State Street Global Advisors. 'This is back to the basics. It's no messing around. It's go hard or go home.'

CrossFit workouts are hands-on, relying only on weights and simple props. The majority of the regime is gymnastics, sprints, Olympic weightlifting and calisthenics. The gym's set-up is deliberately barren. 'When you look around, you can see that you're going to have to work hard. It's an open space and that's pretty much it,' James says.

The floor is covered in black rubber and a handful of props line the edges of the room. Walls are bare aside from a few pedantic posters. One has an arrow that points from 'Death' on one end to 'Super Fit' on the other, with the question: 'Which direction are you moving?'

Morning sessions at CrossFit, scheduled before the markets open, begin at 5am and run through to 8am. Although CrossFit was concerned about opening in a far-flung location like Quarry Bay, James says people are more than willing to wake up at the crack of dawn to work out.

While CrossFit's prices are close to double that of regular gyms, that does not faze members. On average, they attend three to four times a week, which can cost up to HK$2,400 a month. Some even attend daily.

Perhaps the biggest difference between CrossFit and group fitness classes at other gyms is that progress is monitored publicly. Everyone's times and the quantity of weight lifted are written on a whiteboard. At the end of the day a photograph of the board is posted online so people can track and compare their achievements with others.

'It's there for making people accountable for what they do. If someone is lazy today, they stand out,' James says.

For Themistocles, the intensity is part of the appeal: 'It's harder than anything I've done. It's such a physical load and mental workout.'

He attends 6am classes at least three times a week and on weekends.

While it may not be blatant, most people who attend sessions have a competitive streak and are self-conscious of how they rank in the group.

'We've got some very competitive people. You can see the satisfaction in people's faces when they get one up on somebody else,' James says.

Coming from reward-driven and often cutthroat environments like investment banks and trading floors, it seems only natural for finance professionals to evaluate progress.

'It's a friendly competition but not your work type of competition. So it's good to have something different,' says Bonnie Lau, vice-president of international corporates, commercial banking at HSBC.

Lau is enrolled with Bootcamp, a programme similar to CrossFit Asphodel, which takes place outdoors. On a recent Monday evening, she arrived at Hong Kong Park prepared for an army-style workout session. After the trainer did a headcount, Lau and the group followed him into the park. On the way, a cluster of bankers discussed the merits of Bootcamp. 'Gyms don't work,' one announced.

It comes as no surprise that finance professionals, motivated by year-end bonuses that can be as high as 50 per cent of revenue, gravitate to workouts with set objectives.

Bootcamp founder Nathan Solia says people who sign up for sessions tend to be very goal-oriented.

'It's more A-type personalities, they are go-getters, warriors, fighters. They like that little bit of pain,' he says. 'They are not the sort of people who would go to yoga.'

The cost of sessions varies, but monthly membership with Bootcamp is approximately HK$1,200, with single sessions at HK$200.

'It is pricy but you have a trainer with you there motivating you, which you don't get in the gym,' says Aline Ayotte, division head, international corporates at HSBC.

Bootcamp trainers make use of the city's terrain, forcing clients to sprint up and down staircases or do lunges on steep slopes. Sessions often involve calisthenics, interval training and weight training.

'You burn a lot more calories in one hour than you would at the gym on a treadmill,' Lau says.

For many bankers, it's the efficiency of Bootcamp workouts and the proximity to their workplace that make it worthwhile. Ayotte says one of the main reasons she joined was because Hong Kong Park is near her office.

Lau, too, returns to work immediately after Bootcamp training ends at 7.30pm. Other bankers attend morning sessions near their homes.

Perhaps the greatest appeal of gyms like CrossFit and Bootcamp is the sense of accomplishment participants feel after each session.

'They can look at the workout on the board and probably have a lot of doubts. But no matter what it is, people will show up and they will finish,' James says. 'They can get through something that didn't seem achievable, and that carries over into everyday life.'