Fitness clubs are increasingly diversifying the activities they offer in a bid to make a workout as fun as possible.

Far from having to bicycle through puddles and traffic, exercisers at one gym are working up a sweat on stationary bikes in a darkened room, under a mirrored disco ball and to the throb of pumping music. They lurch wildly and punch the air in time with an instructor's commands.

That is the scene at Feelcycle, a chain of seven cycling fitness studios across Japan operated by Tokyo-based Venture Bank Inc.