About half way through the 50-minute session, while doing intervals at various intensities, I got into the rhythm of it. I felt my legs, abs, arms and back working to power through each stroke. Surprisingly, my lower body was doing most of the work. As my heart raced, I could tell I was getting as good a cardio workout as running, but minus the pounding on my knees. I blasted about 500 calories (a 145-pound woman will burn between 400 to 600, depending on intensity). Plus I was toning my upper body, which is a boon for me since I rarely have enough time to fit in weight training. "People have totally redefined their bodies, tightened their butts, their abs and their core," says Crosby.

We finished class with a 500-meter race, measured on our display screen. As if we were competing in the Olympics, we split into teams representing different countries. I was rowing for South Africa and not wanting to disappoint my teammates, a 65-year-old class regular to my left and a 30-something first timer to my right, I pulled full force. Team South Africa didn't win, but we crossed the finish line strong, proud and exhilarated.

Where you can try it: Revolution Fitness in Santa Monica and The Sports Club/LA in Los Angeles, Beverly Hills, Orange County, New York City. For more information, go to indo-row.com.