How I stayed in the fat burning zone for 23 hours and 26 minutes!!!

How I stayed in the fat burning zone for 23 hours and 26 minutes!!!

If you are fast at math you might have asked, so you were out of the fat burning zone for 34 minutes?

Yes.

This is one of those “things” that get’s people confused all the time.  We see this fat burning zone everywhere.  On magazine covers, in conversations, and even on exercise equipment. 

Now I don’t know about you but if I see the words fat burning zone that sounds pretty attractive to me.  Who wouldn’t want to be there?  Burn fat in the fat burning zone!  It sounds almost like paradise.  So how did I spend all those hours in the fat burning zone?

I went for a 34 minute run.  (well 33:54 to be exact (I rounded))

I got one of those heart rate monitor watches for fun and this is what it told me:

I was in “fitness” for 33:40 and “fat burn” for only 14 seconds?

NOOOOOOOOOOOOOOO!

33 minutes and 40 seconds wasted that I could have been in FAT BURNING ZONE!!!!

I spent all that time in stupid “fitness”. 

Ok so I’m messing around a little on purpose.  But, a lot of people would look at that and get a little sad.  Most people are working out because they want to decrease the fat on their body and what better way than “fat burning zone” right? 

Here’s the deal:

You spend all day in fat burning zone!

“Wait Jeremy, how is that possible?  I’m still fat!”

This is the reason I despise the “fat burning zone” label.  In order to stay in fat burning zone on the treadmill, elliptical, or my watch, you have to workout at a low intensity level.  Like on my watch it took me 14 seconds to get my heart rate so I was out of the mythlogical zone. 

What is Fat Burning Zone?

It is an intensity level where a higher percentage of total energy burned is coming from Fat.  Whoa, weird sentence.  Let me explain it a little better.  At any given time,  total energy burned from all sources equals 100%.  At lower intensity levels,  the highest percentage is fat, let’s say 65% of energy burned is from fat.  This usually means about 35% is coming from sugars.  When I get my heart rate up higher,  I leave the "fat burning zone" because the percentages of the types of energy are changed.  To go harder in the workout,  our fat metabolism cannot keep up with demand for energy, so we have to metabolize sugar at a higher rate.  So the percentages might become 40% of energy to run is coming from fat while 60% of the energy is now coming from carbohydrates. 

At this point, fat burning zone still sounds like a good idea.  I’ll fix that. 

While the percentages of energy coming from fat have lowered, fat metabolism has actually increased.  It’s just that the sugar metabolism increased even more!

Let’s put some imaginary numbers behind it to try to understand this concept.  At rest, I burn about 2 calories per minute.  1.5 of those calories may be coming from fat and .5 calories are coming from sugar.  I’m in the fat burning zone, 75% of my energy is coming from fat. 

When I run,  I burn 10 calories per minute or more.  3 of those calories might be coming from fat while 7 of them are coming from sugar.  I’m no longer in the fat burning zone because only 30% of my energy is coming from fat.  But wait, my total fat metabolism increased from 1.5 calories per minute to 3.0 calories per minute.  So at higher intensity you actually are burning more fat,  just not as a high a percentage. 

So fat burning zone is not something to strive for in a workout as we do actually spend all day in this “fat burning zone”.  When it comes to exercise,  a better goal would be to burn as many calories as possible in the time that you have available.  In fact,  that makes a good goal for the day too!

So my run with only 14 seconds in “fat burning zone” was not a failure but a great success!   Don’t let that title fool you any more.  “fat burning zone” is not the key to losing more fat off your body.