I know I'm going to ruffle some more feathers out there by posting this, but hey, I'm here to help you get real information that will help you make choices and take actions that will get results! 

I'm not here to just tell you what you want to hear.  No, I want you to hear the truth, with evidence, and be able to make an informed choice from there.

I realize that will not necessarily make me the most exciting or popular person out there.  But for those brave enough and serious enough about making changes in their bodies, by getting out of pain or transforming their body -- those people will appreciate this post.

I recently received this question that made me realize how many people out there are still using the heart rate info on machines as guides on how to transform their bodies.  So let me give the truth.

In reference to the heart rate ranges posted on exercise equipment.  They identify what your targeted heart rate should be if you want to burn fat, etc. based on your age.  In my case, my heart rate while exercising is ALWAYS higher than that "fat burn" range. I would have to significantly slow down my pace in order to fall within that range.  If my heart rate is not within that range, am I not burning calories efficiently?  Is there a lot of merit to those targeted heart rate ranges?  If I am not sweating, I don't feel like I am working hard. -- Nikkie

Target Heart is highly flawed.  I have personal experience with contacting the user of some of these formulas and they had no real idea why they used them accept to say, "They were the popular tools used at the time".  Guess it really doesn't answer why once they see the flaw they continue to use antiquated information.

To the point.

  • Target heart rate is inaccurate for 70% of the population by 10-12 beats per minute.  Not such a big deal right.  But get this, for 30% of the population it's off by 20-24 beats per minute.  That is a big deal.  Knowing which group you fall into can only be found by using your own heart rate monitor.

  • The Fat burning zone is supposed be the heart rate range where you will supposedly burn the most fat calories.  Truth is, it cannot predict this.  At best it can only partially suggest a percentage of use of fat, carbohydrates and protein.

  • You burn the most fat at rest.  The more intense an exercise is, the more carbohydrates will be used as the primary fuel source.


Low Intensity - 60-65% MHR High Intensity - 80-85% MHR
Total Calories expended per min. 4.86 6.86
Fat Calories expended per min. 2.43 2.7
Total Calories expended in 30 min. 146 206
Total Fat calories expended in 30 min. 73 82
Percentage of fat calories burned 50% 39.85%

From The 24/5 Complete Personal Training Manual, 24 Hour Fitness, 2000



I think this chart simply and accurately explains why using intervals (alternating periods of fast and slow) instead of the steady state "fat burning zone" cardio, is the most effective way to shed body fat quickly and effectively.

Slow, steady state cardio just doesn't cut it when it comes to losing body fat quickly and effectively.  Not to mention the wear and tear on the knees, hips, and lower back.

And this is the part that everyone seems to forget so readily -- what happens after that intense exercise circuit you just finished, or that extremely challenging cardio interval session.  There's something called EPOC.  Which basically discusses the amount of calories being burned after an intense session of training that can last up to 3 days later.

You will be burning more calories after intense training session because your resting metabolic rate is higher (you won't get that from "fat burning zone" cardio).  And if you'll remember, when do you use fat as the main source of fuel -- AT REST!

And if that wasn't enough information to convince you, check out this article The Final Nail in the Cardio Coffin.

Get On Track and Stay on Track!