Have you ever been on a treadmill and saw a chart that had something to do with the fat burning zone, or heard fitness professionals tell you that working at a low-moderate intensity burns more fat that working at a higher intensity? This is one of the true gimmicks of the fitness industry, and I'll explain why.
The reason that there is a "fat burning zone" is because of relativity. When you exercise at a low-moderate intensity a larger percentage of the calories you burn will come from fats than other substrates. However, working at a higher intensity will still burn more total fats than will moderate intensity because, even though a lower percentage of the calories burned will come from fats, calories are being burned at a higher rate. Still confused? let me do a little math for you. Please bear in mind that the below figures are rough estimates. you may find research out there that says moderate intensities burn 24% fat and higher intensities burn 15%. Typically, these lower numbers will be referring to free fatty acids. There is also an apparent difference in whether you're running or cycling, and also whether you're male or female, but I think that may be a topic for another post. So, without further ado, the general premise:
A moderate intensity exercise will burn approximately 50% of its calories from fats
A high intensity exercise will use approximately 40% of its calories from fats.
So let's say that you work out at a low/moderate intensity for 20mins, burning 150 calories. The math tells of that total calories from fats will be:
150 x 50% = 75calories.
Now, let's take that same 20mins at a high intensity, burning 220 calories.
220 X 40% = 88calories
There you have it. The higher intensity, while burning less calories from fat relatively actually burns more total calories from fat absolutely.
On an unrelate note: thanks for sticking with me guys. life on this side of the blogosphere has been very busy for various reason. I had been finding it difficult to get motivated to blog, but I'm slowly brining myself out of that slump. You may have noticed some changes to the layout of the blog. I'm trying to make everything more organized so you fine folk can find the articles you want without too much difficulty. Have a look at the footer to see the main changes. Finally, please, if you're reading, leave me comments. I want to get engaged with my readers. I piloted having a forum a while ago, but it didn't get a great deal of attention. So, if you have a question please leave a comment, or email me. I'm happy to answer any and all questions, or at least point you in the right direction.