Which is a better workout -- treadmill or elliptical machine?

Most people think that treadmills offer the best blend of exercise and perceived exertion, but recent research at the University of Mississippi suggests that elliptical cross-trainers can offer a comparable workout.

In the study comparing cardiopulmonary responses of patients recovering from cardiac disease, subjects exercising at the same level of exertion used 12% more oxygen and experienced greater cardiopulmonary activity with the cross-trainer than with a treadmill. The impact was lower, as well, an important consideration for people with joint problems.

Ultimately, you should take into consideration your body type, age, injury history, goals -- and which you prefer using.

Stephanie Oakes is a fitness correspondent for Discovery Health Channel, a contributing editor for USA Weekend Magazine and the LA Times, and appears on NBC's 'Today in New York'. She can be reached at soakes@beststuff.com.