I read this article on Yahoo! today, and wanted to share it.. These are myths that are still very common among many gym-goers, and they can really hinder your progress. The one I want to talk about a little more in-depth, because I hear it still floating around a lot, is the “fat burning” zone. This is one of my least favorite phrases to hear. For those of you that have not heard the theory before, it claims that if you keep your heart rate at 60-70% of your maximum heart rate, you will lose weight faster because your body burns more fat calories in this zone. This is not the case. Think about it-if you could lose more weight by putting in less effort, don’t you think everyone would be skinny?? Here is the breakdown-when you keep your heart rate between 60-70% of max heart rate, you do burn a higher percentage of fat calories. But you burn less calories overall, and the math does not work out in your benefit. We’ll use the example from the Yahoo! article, but elaborate a little.
Let’s say you walk for 30 minutes at a slow rate, keeping your heart rate at 60% of your max heart rate and you burn 250 calories. Or you could speed it up and bump that heart rate up to about 80% of your max heart rate and burn 500 calories. Now for the math…get out those calculators!
Say you are burning 45% fat and 55% carbs at your lower heart rate. You burned 250 calories, so approximately 112 calories burned are fat calories.
Now you increase your heart rate, and 35% of your calories burned are fat calories and 65% carbohydrates. You burned 500 calories, so that’s 175 fat calories. And double the total calories.
In case that’s still not clear, let me put it this way. Sitting there reading this post, you are probably burning at least a whopping 60% fat calories. Let’s think about how many total calories you are burning though…do you think you will lose weight with this method?
Let me know if you have any questions about any of the myths-I’ll be happy to try to clarify, or post some of the research studies on the topic!