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Heart rate zones and exercising
By workoutmommy | January 11, 2008
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Leticia emailed me recently with a great question:
“Why is it important to keep your heart rate at 60-70% of max heart rate for weight loss purposes? What will happen if you exceed this? I’m seeing the people on Biggest Loser and am having a hard time believing that they are exercising at 60-70% of their max heart rate…and they are losing weight…so why shouldn’t we just exercise at as high an intensity as we can withstand?”
You are correct Leticia, there is no way that the contestants on Biggest Loser are staying below 70% of their max heart rate during their workouts. (at least not the workouts we see snippets of!)
You can see it on their beet red faces, as they sweat profusely, and some of them even throw up. (which is a classic example of someone exercising too hard, too fast and is not somewhere that you want to be!)
For them, it is a competition and they are trying to lose a lot of weight in a relatively short amount of time. There are plenty of debates as to whether their weight loss is healthy or not, so I’ll steer away from that topic. (for now!) But basically when you work out in the high end zones (80% or more) you are burning more overall calories.
This leads me to the ever popular myth of “fat burning zones”. I have met with many clients who tell me they want to stay at the lower heart rate zone because they will “burn more fat”. This is not really true.
Yes, higher intensity exercise uses more glucose and glycogen (the form of energy your body gets from foods) in proportion to fat, but weight loss is more about overall calorie burn. In order to lose one pound of fat, you must burn 3500 calories. Does your body care if you spent 3 hours or 1 hour to burn those calories? Heck no!
Here is an example:
In one hour, you run 6 miles. Let’s say your body burns 35 calories per mile. (just an estimate here!)
Therefore in one hour you will burn 210 calories. (6 X 35=210 calories)If you were running at just 60% of your max heart rate then you would burn 126 calories. (210 X 60%=126)
If you were running at 75% of your max heart rate then you would burn 158 calories. (210 X 75%=158)
I don’t know about you, but if I have a spare hour to run (or any kind of exercise) then I want to burn as many calories as possible! Yes, I could burn even more calories if I ran at 90% of my max, but it is not something I could sustain for very long, much less an hour. Therefore, my overall calorie burn would be lower because I could only do it for a few minutes before I was exhausted.
Exercising too hard, too fast, and too often is one of the reasons many people quit exercise altogether. They start to think of it as very painful and often times develop an injury. Exercise should be challenging, but still enjoyable. (yes, it can be, I swear!) If you are always pushing yourself to the brink (and throwing up), then of course it isn’t going to be fun.
This is why I really love interval training because it really gives you the best bang for your buck. Not familiar with interval training,? Here is a great explanation from the folks over at Sixwise.com.
So to sum up, if you are looking to lose weight, you should exercise at higher intensities (but not too high!) to boost your calorie burn. On days where you do not have an official workout, just decide to move more. Take an extra walk, take the steps instead of the elevator, etc. Of course the most important thing is to be mindful of what you eat! So, many thanks to Leticia for submitting a great question!
Now, ask yourself right now! Have you been active today?
Get up and get moving and enjoy your energy!
NO EXCUSES!
Topics: biggest loser, questions |
January 11th, 2008 at 10:34 am
Thanks for the answer!
January 11th, 2008 at 2:41 pm
You put that so well, Lisa! The heart rate myth is one of my pet peeves, so thanks for addressing that as well as the too-much-too-soon problem. I seriously want to print this out and tape it up all over my gym.
January 11th, 2008 at 5:16 pm
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January 12th, 2008 at 5:16 pm
That was great to know! And yes (!) I have moved today.
Although I have yet to figure out how to exercise with 5 kids and snow outside, we all cleaned the house together running and taking the stairs as much as we could. By the end we were tired, a bit sweaty and my house looked much better. You’re proud of me, I can tell.
January 15th, 2008 at 11:07 am
[...] Heart rate zones and exercising [...]
January 20th, 2008 at 8:54 pm
[...] Heart rate zones and exercising [...]