Rowing gives you a great aerobic workout and exercises all the body's major muscle groups - you use your legs and buttocks as well as arms and back. It also burns lots of calories, but unlike such high-impact aerobic exercises as running, it is easier on the joints. Rowing is even recommended as a good low-impact aerobic exercise for people with arthritis, provided that their elbows are not affected. Depending on how vigorously you row (and how much you weigh) you can expend from just over 400 to more than 1,000 calories an hour by rowing.
Reportedly, rowing is becoming more popular across the United States, and if you're lucky enough to be able to row on the water for all or part of the year, your workout can also provide the enjoyment of being outdoors.
For most people, however, rowing means using a rowing machine in a gym or at home. I'm told that for weight control and general fitness, the "long row" should be part of a rowing routine. But, as I understand it, "long" is relative. If you're a neophyte, a "long row" might be only 20 minutes. If you're experienced, your "long row" would be about 45 minutes and competitive rowers might go for an hour and a half. As with other aerobic activities, the pace of your rowing should not be so intense that you can't keep up a conversation with someone. (Having a buddy who rows with you can help with motivation and pacing.) Finally, be sure to get qualified instruction before you start; without proper technique you can easily strain your back.
Andrew Weil, M.D.