The rowing machine is having its moment

The rowing machine, often considered retro and dull, is making a comeback in the most surprising fashion: the group fitness class.

Dubbed the "hip, new king of cardio" by Details magazine, rowing machine classes have been taking off in gyms around the globe, including recent launches of Equinox's Shockwave rowing-based circuit training class in the US and Pure Gym's Pure Crew in the UK.

In New York the trend is particularly popular, with fitness studio Indoorance using row machines for partner-based workouts that simulate rowing on water. Also Brooklyn's new Brooklyn Crew just opened a fitness center devoted to the genre, and a studio called Row is scheduled to open in Manhattan's Union Square later this year. Why? Devotees say that it's long been an underrated piece of gym equipment, and now that its design has been improved, with affixed water tanks and machines carved from wood to simulate true crewing conditions, it's only growing in appeal. Plus the surge of back-to-basic fitness, popularized by Crossfit, has possibly turned people on to the possibilities of the machine, reports fitness blogger Well + Good NYC.While rowing won't likely supplant spinning classes anytime soon, a 50-minute class can burn as much as 1,200 calories, about twice as many as spinning. Plus you'll work every muscle in your body -- not just the upper body -- which gets your heart pumping but without risks to your joints.