Monday, March 03, 2008

How To Guide: Exercising to Burn Fat

"Those who think they have no time for bodily exercise will sooner or later have to find time for illness" ~ Edward Stanley

When it comes to how I look & feel, I could care less about how much I weigh. Whether I weigh 240 lbs or 190 lbs, it makes no difference to me; providing that the weight I'm at is at a healthy body fat %........which indicates that the majority of the weight would be in the form of lean muscle mass, bones, water...etc.

As you know, I think that the BMI is crap.... therefore based on the above line of thinking my main focus is really on losing fat and lowering my BF% to a healthy range......but what is a healthy BF% range? This depends on what source you prefer to abide by.











This graph based on NIH/WHO BMI guidelines. As reported by Gallagher et al at NY Obesity Research Center.

~ Tanita

It's not easy finding a clear, concise and agreed upon answer.....trust me, I spent quite awhile Googling an answer. If anyone out there is aware of a reliable, trusted source let me know....as for now I'm going to stick with the above graph as my guideline.

So, based on the above graph, my "healthy" body fat range (34yrs old) is between 8 & 20%. My primary goal is to get out of the obese range. My secondary goal is to move from the "Overfat" range down into the "healthy" range. My final goal is to shoot for a target somewhere around 15% body fat....but realistically I'm not sure if this is too lofty of a goal, or not lofty enough. I should have a better idea as I move from one goal to the next.

Now that I set goals in regards to reducing my BF%, the next question is what is the ideal way to exercise in order to lose the optimal amount of BF? I've done enough reading (magazines, books & online) to know that there are some very good exercise routines, created specifically for this purpose. However, I'm not ready to change my exercise routine....maybe when I've lost another 10-15 lbs. For now I'm content to just keep using my elliptical machine, walk & do some light muscle building exercises.

Up until just recently I still believed that there was an optimum HR (Heart Rate) to exercise at the would put you in what is know as the "fat burning zone". In this zone you burn a higher % of calories from fat. If you exercise too hard your HR rises and takes you above this "fat burning zone" and you end up burning a higher % of calories from stored carbohydrates. This belief is true, but it's flawed. Consider the following:
For example, say a 140-pound woman performs either a fairly easy walk or a high-intensity jog. After 1 hour, she would have burned the following in total and fat calories:
Busting the Fat-Burning Zone Myth

Moderate Intensity
High Intensity

(60-70% max HR)
(70-80% max HR)
Total calories burned: 192
278
% of fat calories burned: 75%
50%
Total fat calories burned: 144
144

As you can see, you would burn just as much fat and significantly more calories by working out at a higher intensity. What's more, high-intensity aerobic exercises kick your metabolism into high gear even after you're done working out.

~ Prevention Magazine
Based on this information it's better for me to exercise at 70-80% of my maximum heart rate. To do that I need to figure out what my HRmax (Heart Rate Maximum) is.
A 2003 study of 43 different formulae for HRmax, concluded that the following formula was the most accurate:
HRmax = 205.8 − (0.685 * age)

- Wikipedia
Using this formula my HRmax is 182 bpm (Beats Per Minute). To exercise at the 70-80% HRmax I need to raise my HR to between 127 - 146 bpm.

Once I've managed to lose another 10-15 lbs I will return to this topic and reanalyze my exercise regimen. Hope this post helps everyone.

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3 Comments:

Blogger Fat Lazy Guy said...

The only problem (and I don't really know that it is a problem) I see with the quote from Prevention Magazine is it doesn't take into account that while some people may be able to walk for an hour, they might not be able to jog for an hour.

6:16 AM  
Blogger BryGuy said...

That's an incredibly good point...one which I thought about but failed to discuss. Most fitness/medical professionals recommend a minimum of 20mins of continuous aerobic exercise to see the full benefits.

20mins at a higher intensity level is within my ability....1hr...not so much.

Another thing this article didn't address is that any exercise, whether it be 1hr or 5mins, at any level of intensity is beneficial.

The most important aspect of exercise is actually getting some, and over time trying to increase your level of fitness/intensity.

Thanks for the comment FLG.

10:05 AM  
Anonymous Anonymous said...

Look up HIIT. And get a heart rate monitor.

I'm using a three-phase interval that I modify from week to week to add intensity. In the past three months, I've lost over 15% of my body weight from fat. I've probably actually lost more than that as I've also gained muscle. Some Japanese study showed that exercise interspersed with rest burned more fat than steady exercise.

Remember that the first 10 minutes or so of aerobics (depends on your body) will burn off sugar in your system before working on the carbs and fat. I built my exercise plan on the theory that I don't want to have to work those 10 minutes off after every rest period.

I swap between a recumbent stationary bicycle and a rowing ergometer. I'll do a stint on the bicycle at 40-55% of HRmax, then a 10 minute piece on the erg. I break the 10 minutes up into four pieces of 2.5 minutes each with 2 minutes at around 60-70% HRmax (I run a steady pace around 2:10/500m) and then go all out for 30 seconds .. usually about 17 strokes that I count in my head because I could utter anything other than a grunt if I wanted to.

The trick is to really go all out in the anaerobic intervals and slow enough that you can recover sufficiently during the break to do the whole of the next one. Start easy and stick to something .. anything for a week. Try increasing your "rest" pace the next week or increase the amount of time you're engaged in working out. Recognize that this will take months and try to not look at the scales more than once every second week. I jump on the scale on the first of the month and I get to see substantial results that really help me keep going.

12:26 AM  

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