Both the air rower and water rower machines are very popular choices of rowing equipment, particularly the former type. They have been around in the 80s, and many consumers and those that have tried them in gyms consider the equipment to be the best type ever. These air resistance equipment, often regarded as Ergometers, is the standard base model for indoor rowing sport.
From a fitness perspective, the WaterRower Natural works 84 percent of your muscle mass, helping tone and strengthen your muscles while burning far more calories than most other aerobic machines. The exercise is also low impact, as it removes all the body weight from the ankles, knees, and hips, but still moves the limbs and joints through a full range of motion--from completely extended to completely contracted.