Photo provided to China Daily

Each stationary bike is equipped with a dial that controls a weighted flywheel to simulate riding on flat or hilly terrain. The intense series of hill climbs, races and interval training mean riders can burn up to 600 kilocalories per session. Hamstrings, quadriceps, backs and hips get toned. More importantly, the heart gets a workout, which can result in sharper concentration and increased stamina.

Koo feels that like in New York and other big cities, there is room in Hong Kong for specialized exercise studios such as XYZ.

"Other spin studios here tend to be behind glass walls with normal speakers, which makes riders feel like they're inside an aquarium," she says.

"Our studio contains 48 bikes inside a dark theater setting, and our classes are led by one of five international instructors. Each has his or her own cycling style and playlist, which they upload on our website regularly. It's exercise as entertainment."

If a rider feels unwell, the club offers sofas for resting and all staff members have St. John's ambulance training.

With interior design courtesy of Studio SSMC New York and Hong Kong lighting guru Tino Kwan, XYZ is more like a hip urban spa than a gym. Raw concrete and dramatic lighting extends to the large reception area that doubles as a retail space for cycling gear, with change rooms and showers for men and women veer off to either site. In the rear, a relaxation area provides an anteroom to the studio itself.

"The look is very street but also sophisticated," Koo says.