Contemporary rowing machines bear only a slight resemblance to their ancestors. But, like the older ones, a modern rowing machine provides a full body workout.

Picture a platform with a seat. Now imagine something to grab onto and pull backwards against resistance. That's a rowing machine in a nutshell. But from that elementary starting point, the designs vary widely.

Some machines look a lot like a rowboat of the type that might have been used at Cambridge University in the 19th century. With long oars set in a guide, a crew of six or more could glide through the water at a speed they hoped was a little greater than their rivals at Oxford. Today's adaptation puts the boat in drydock and shortens the oars, but the look is much the same.

More up-to-date designs will Read more