Before I started running and during the first stages of my running when it did not take up as much time, I used a rowing machine for cardio. I love the rowing machine and would like to buy one. I have not gotten around to getting one yet but I am pretty sure I will in the future. It is such a good work out for the whole body. Most people think that it is all back and upper body but that is not the case. If you do it correctly you will use your legs to produce most of the power and that is a good thing because your legs and your butt are your biggest muscles. They make up 50% of your body so they burn the calories. Do you know of any activity that really burns the calories that does not use your legs? Anyways, here is a video that shows you how to use a rowing machine the correct way so when you are at the gym you’ll look like a pro.