Who can find time to exercise these days? Oh hey, you can. A recent study appearing in the Journal of Physiology explains that, contrary to popular belief, cardio exercise doesn't have to be a time suck. According to the study, interval training, which takes less time to perform than traditional endurance exercise, can be just as effective.

Interval training involves varying the pace of whatever cardio exercise you're doing so that you can get more done in less time. Here's an example: while on the ol' bike, pedal really fast for one minute, then slow down your pace for the next minute to recover, then pedal really fast again for one minute, followed by another minute recovery period...you get it. Repeat until you've been at it for 20 minutes or so. It's as simple as that.

The study found that participants who practiced interval training experienced the same health benefits—including lessening the risk of heart attack, stroke, and diabetes—as those who followed a regimen of longer duration workouts at a moderate pace. In fact, over the course of the 14-day study, it took a total of 10 hours of moderate exercise to achieve the same health results that participants achieved after a total of only two hours of intense interval training (in six 20-minute sessions over the course of 14 days). What what!

And as for calorie burning, our expert, Los Angeles internist Dr. Andrea Ruman says, "Research shows that you burn more calories performing high intensity interval training than you would performing moderate intensity workouts of equivalent lengths." So, for example, you'll burn more calories doing high-intensity intervals on a bike for 20 minutes than you would burn biking for 20 minutes at a constant moderate intensity.

Looks like now you'll have more time to brush up on that second language you've been meaning to learn—or, who are you kidding, catch up on episodes of Bethenney Getting Married.

This article has been republished with permission from ChickRX, expert health advice and questions answered for the 20-something woman.

Photo courtesy of lululemon athletica.