Yah when I saw the thread title I assumed he meant weight training. A rowing machine is probably one of the best all around cardio workouts you can do but I think a combination of distance running, sprints and ice skating would be a better conditioning tool for skiing. Rowing ain't doing jack for your legs.
Exercising and skiing go hand in hand. When you've got a strong legs and core your body can withstand a lot more punishment. Kind if like a "bending but not breaking" sort of thing. I don't know how it works but I try to keep myself in shape and I've never broken a bone in my life and I take some pretty reckless risks.