Yes, it is indeed satisfying to feel the ache in the muscles after the exercise. I often think that it is funny when we were children or younger then no matter how much we did run, played or played any sports we did not have any problem with muscle aches and I remember I was not able to understand my grandma when she was complaining about her muscles. But slowly I do understand that without regular exercises even in healty persons muscles and joint become weak and stiff. The rowing machine is great, whenever I have time I try to use it :)