Definitely NOT the fittest person when I first walked into RowZone, not even close to it. BUT I've been going twice weekly now consistently for over a month - 04:30 classes on Tues & Thurs. With each class, I come out totally exhausted - out of breath, muscles feeling spent and just a big sweat ball, but with each class I feel a bit stronger and my endurance is getting better. I work at my own intensity, but always have the encouragement by my instructor to push myself a bit further "It's only 20 seconds of your life so make it the best sprint!" I feel it's a perfect blend of cardio and strength training in 45 min. Am on my way to better health. I think I'm hooked - Thanks, RowZone!