Setting up an effective cardio program for weight loss can be confusing. The guidelines of the American College of Sports Medicine (ACSM) suggest:

    For health benefits: Thirty minutes of moderate intensity exercise, five days a week or 20 minutes of vigorous cardio, three days a week
    For weight loss: Working up to 60-90 minutes of activity several days a week

What the guidelines don't explain in detail is how to set up a routine that incorporates a variety of workout intensities, activities and durations. If you only do slow workouts (or staying in your 'fat burning zone'), you not only risk boredom, you may experience slower weight loss. Working harder forces your body to adapt by building more stamina, all the while burning more calories. On the other hand, too many high intensity workouts can lead to burn