I absolutely adore rowing, definitely recommend. Concept2 are the best machines they can be expensive if buying yourself, around £600+ second hand, but well worth the investment as it's a full body workout. It's lower impact on your knees, too, apart from the bend and flex movement on the forward push back motion. It still won't send your knees to ruination, though, only if you're battering it out on there day in, day out. It's also great to build definition, specifically the lats/back and legs, and it scorches calories brilliantly well. I have a home rower, but I want to get a Concept2 to start putting in some serious cardio hits when I'm at home. Also, checkout YouTube, there's some excellent training videos about rowers and technique, and ideas for sprints and mini challenges you can set yourself to achieve specific goals you're after or even just to keep mixing things up. If you get technique nailed, you'll swerve injuries and see results quicker. Highly recommend the rower, they're ace!