The 30-minute fat blaster

Limited time for the gym?

Here's how to make the most of it.

FIND AN EMPTY MACHINE Don't worry if it's not your favorite type of cardio. You won't be there long, instead of slogging away on one machine for your entire workout your new goal is to rotate among three to four different options, hitting each as hard as possible and keeping your rest period between machines as short as possible.