Rowers are in a class of their own for a really intensive upper and lower body exercise workout. Serious training can be done with any piece of quality cardiovascular equipment, but rowing machines really lend themselves to the dedicated fitness enthusiast, particularly those who enjoy rowing! Rowers have 3 main forms of resistance. Air rowers like the Concept2 Model D give an excellent smooth action and full length stroke. They come closest to simulating the action of rowing on water, together with Water Rowers, where water provides both the feel and sound of 'the real thing.' Magnetic rowing machines give a smooth and variable resistance and are generally shorter which may be a factor where space is limited, and you do not have much room for exercise machines.