What Gives?

I consider myself fairly health savvy.  I know that I need to limit fat, carbs and sodium.  I know my numbers.  I try to be active at least 4 hours a week.  I was looking for something to help me monitor my workouts, and was perusing heart rate monitors online when I came across an article about the cardio zone versus the fat burning zone.

Hang on a sec..... WHAT????

Correct me if I'm wrong, but am I not burning fat when I get my heart rate up?

According to what I read, workout intensity can change whether your body is using a higher proportion of fat or calories as fuel.  If you work out at a lower intensity, your body uses proportionally more fat; a higher intensity gets your body burning more calories.

Boy howdy, did I get excited!  You mean I can work out at a lower intensity and still reap the rewards, instead of busting ass for 40 minutes of heart  pumping, sweating like a hog cardio?  Sort of, but no.  Burning calories at a higher intensity creates a bigger calorie deficit (calories in vs. calories out).  And it still burns fat, just not as a primary fuel source.  Burning calories, over time, will lead to a bigger long term weight loss.  To get the same benefits from a lower intensity workout, you'd have to extend the duration quite a bit.  Not that I would mind a longer, less killer workout, but really - who has time for that?

I'm hoping that my regimen is giving me the best of both worlds.  It's good to know that the days I do the less intense workouts - still hard, but my heart rate isn't sky high - I'm still benefiting from my efforts.