No game, no gain.

A Manhattan gym is charging customers $110 an hour for a personal training session – with a Nintendo Wii.

Super Mario’s rotund physique may not be what most gym members are shooting for, but personal trainer Dorothy Evans says the video-game system not only gets the heart pumping but might even help her clients lose a few pixels in the process.

“You’d be surprised. It may have little to do with the real sports, but we get people’s heart rates up to 140 to 150 beats per minute – although some of that may just be the excitement of the game,” said Evans, who gives Wii workouts on a 20-foot screen in what otherwise is used as a racquetball court at Gravity Fitness at Le Parker Meridien hotel.

It may sound crazy, but between treadmills and elliptical trainers, gym members already are accustomed to working out with machines while staring at TV screens, said Mark Natale, Gravity’s executive director.

“We think of this as just another tool at the gym,” he said.

Evans combines Wii Sport games, like boxing, tennis, golf and dodge ball, with the real thing.

For instance, in her boxing class, her clients first put on real gloves and learn to throw jabs, crosses and hooks. And in between these real punches and cardio drills, they get to play the game.

“I use it in what we call ‘active recovery time,’ during which normally I would have them do a wall sit,” she said. “But this is like a reward.”

Video games may normally provide only physical training fit for a thumb fight, but the Wii, if used properly, can be a full body workout, Evans said.

Clients at the gym were skeptical at first.

“When you envision someone playing video games, you get a vision of some kid zoned out. Or you get the picture of that slacker in his mom’s basement,” said Robyn Angrick, 29, who has had two Wii boxing workouts.

“I decided to give it a try to break up the monotony – I just felt like I was in a rut,” she said. “But I was not really prepared – it kicked my ass.”

A study by the American Council on Exercise found that although playing the Wii is no substitute for the real-life sports, it is possible to burn almost as many calories.

For instance, Wii Boxing burns an average of 7.2 calories per minute, compared to 10.2 calories in actual sparring.

jeremy.olshan@nypost.com