I used to run almost every morning, but long story very short I can't anymore and i'm looking for a cardio workout to do in my basement, preferably with a machine. I'm not a fan of stationary bikes and someone recommended one of these rowers, but the few times I've tried them I never seem to even break a sweat even if I do like the idea of them seeing as they work so many muscle groups at once. Thoughts? And this is just for cardio / endurance not for strength