The theory that working out in the fat burning zone is still floating around out there in the fitness world. A couple of you have asked me about this, and though it is pretty simple science it can be a little confusing. The bottom line is the more intense a person exercises the more calories they burn in a specific time frame. So, if you are injured and can not move intensely, you need to move for longer. I found this great article on Builtlean.com that reiterates what I have been telling some of you…
High intensity workouts like this one pictured here get a big burn!
To understand the fat burning zone myth, you need to understand how your body uses energy during exercise. To keep things simple, during exercise your body draws energy from primarily two places: fat stores, or glycogen stores. Glycogen is stored carbohydrates in your muscles and liver.
The fat burning zone was conceived because at lower exercise intensities more fat is burned relative to glycogen. Isn’t this awesome? Now you can hang out on the couch and lose a bunch of fat. I hope you are starting to smell something fishy with this idea of a fat burning zone.
At 50% of your max heart rate, your body burns a ratio of 60% fat to 40% glycogen. At 75% of your max heart rate, the ratio is 35% to 65%, and at even higher intensities, the ratio is even lower.1
So why the heck would you want to workout so hard if you burn so little fat?
The reason why is because it’s all about calories. You burn a lot more calories when you workout intensely than you do when you are sitting on the couch.
So here’s what the breakdown looks like assuming 30 minutes of exercise for a low vs. high intensity group. The high intensity group will likely burn double the calories as the lower intensity group, or 200 vs. 400 calories:
|30 Minutes of Exercise||Fat Calories Burned||Glycogen Calories Burned||Total Calories Burned|
|Low Intensity Group (50%)||120||80||200|
|High Intensity Group (75%)||140||260||400|
So now you can see you burn more fat calories at a higher exercise intensity than a lower exercise intensity (140 vs. 120) despite a smaller percentage of fat being burned. But I know you need more convincing because the higher intensity exercise represents only a 20% difference in fat calories burned for a 50% increase in intensity. Not a good tradeoff.
Gumsaba Boot Camp Class schedule Thursday 2/13/14
5:30AM Sunrise Danville Womens only class – Coach Briana – Heart Beat City
5:30AM Sunrise Danville Mens only class – Coach Allen
6AM Sunup Walnut Creek Co-Ed class – Coach Jentry – Strength Sets
9AM Sunshine Walnut Creek Womens only class – Coach Briana – Heart Beat City