Don't have hours to spend at the gym? How long do you need to sweat to make a workout count?

FOX News Radio's Marghiee Teshineh reports in this edition of Housecall for Health":

The latest craze in workouts are circuit training workouts, lasting seven minutes that promise to burn fat and boost your metabolism.

But according to a fitness expert at "Prevention Magazine", these mini workouts have to be done two or three times at high intensity the whole time for maximum benefit. And a proper workout means including a warm up and cool down, so the most effective workout is really at least twenty minutes.

Housecall for Health, I'm Marghiee Teshineh, FOX News Radio.