Elliptical trainers

For a full body cardio workout, elliptical trainers are hard to beat. They are smooth and non-jarring - great for those with a history of injuries - but still provide a workout as tough as you want.

Elliptical trainers have developed out of cross country skiing machines, but the newer models are both easier and more fun to use. They are excellent either as a warm-up before a resistance workout, or as a stand-alone cardio workout.