Calories from fat vs. glycogen calories question

Beatlesboy

Beatlesboy

New member
So I talked to a personal trainer and afterwords did some research online and I'm still confused. Here it is.


He mentioned the "fat burning zone" and how you should work out (cardio) hard, but not very hard because a bigger percentage of the calories you'll burn are from glycogen, not fat. Doing that makes you crazy hungry and your body will turn to muscle, losing muscle as a result.


Could some explain the truth? Basically, I want to work out as much as I want without worrying about losing tons of muscle mass. I keep my diet fairly clean, full of protein and total calories in check. I like to do cardio 5-6 times a week for at least an hour, maybe two. I also weight lift 4 times a week for 45 mins to an hour.
 
I'm not a professional so I can't give a concrete answer, but one thing i would say is (based on your ticker) that your exercise regimen has worked for you very very well so far, and unless the amount you are lifting is sliding backwards and lower, and you find yourself weaker in every day activities, then you probably have nothing to worry about. Great work so far and congrats on the awesome loss!
 
He's a bit confused. Ask him what fuel substrate is predominantly used while at rest. For your information, the answer is fat.

So why don't we rest to burn the fat off?

Simple: Rest doesn't burn many calories at all.

It's about caloric expenditure - and with that in mind, in terms of fat loss, it really doesn't matter what's fueling the activity.

Or you could simply print him off the following article written by one of my favorite researchers and have him read it.
 
Basically the body doesn't burn fat quickly, whereas it does burn glycogen quickly. So if you're doing intense cardio, where you need energy really fast, your body is going to burn glycogen instead of fat. This is because it can't turn the fat into energy fast enough to keep up with what your body needs to keep working at that pace. That's why he said if you work too hard, you burn glycogen, because it's faster for your body to convert it into energy.
 
Beatlesboy said:
He mentioned the "fat burning zone" and how you should work out (cardio) hard, but not very hard because a bigger percentage of the calories you'll burn are from glycogen, not fat. Doing that makes you crazy hungry and your body will turn to muscle, losing muscle as a result.
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My cardio respiratory exercise professor last semester told us that if we maintain our THRs (target heart rates = 60-80% of your maximum hear rate. So .6 or .8 * (220 - your ages) = THR). My target heart rate is between 120 and 160. I usually workout around 140-150 beats/min. She also told us not to worry about the fat burning zone, just as long as you get into that THR, you're good... also said by the American College of Sports Medicine. Maybe the THR method is taking into the fat burning zone into account?? I don't really worry about that kind of stuff lol just as long as I'm in my THR!
 
that method of finding your THR has long been deemed as bad. Heart rate reserve is the accepted standard now.

The fat burning zone is a total myth, and should be ignored as a guide for exercise to lose fat. the working cardio too intensely is a complete and utter myth as well. if it held an ounce of truth every sprinter on earth would be a skeletal looking mess. which is anything but the case......
 
spootiee said:
What's bad or harmful about it? I'm not getting defensive, I'm just curious. :)
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it's bad because it's horribly inaccurate. The idea that your MHR should be based on your age only is laughable because it means that lance armstrong and your 300lbs lady of the same age who never exercised in her life have the same intensity %......

Heart Rate Reserve takes your resting heart rate into account in addition to age thus is better overall for people of different ages and fitness levels.

edit: here is a link that goes more into detail on how to calculate it.....
 
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I understand how you burn sugar calories (glycogen) because it's very "ready" energy if your working out intensely, but my question/concern was that this personal trainer said that when that happens your body will crave food so badly it's almost like a wash because you won't be able to not eat afterwords. Thus burning 600 calories of glycogen and 100 calories of fat in a workout would yield very slow results that could lead to frustration. That the idea was to burn as many fat calories as possible; to work out hard, but not very hard. I thought this might be B.S.

Regardless of where someone's calories are being burned from (sugar or fat) will you not lose basically the same amount of weight if you keep your calorie consumption in check?
 
Jynus said:
it's bad because it's horribly inaccurate. The idea that your MHR should be based on your age only is laughable because it means that lance armstrong and your 300lbs lady of the same age who never exercised in her life have the same intensity %......

Heart Rate Reserve takes your resting heart rate into account in addition to age thus is better overall for people of different ages and fitness levels.

edit: here is a link that goes more into detail on how to calculate it.....
Click to expand...

Oh wow! I understand now, and I think I seriously like this method way better. It's very specific in the zones, which I like. I must try it out tomorrow right in the morning and see how I works for me :) Thanks!
 
Beatlesboy said:
I understand how you burn sugar calories (glycogen) because it's very "ready" energy if your working out intensely, but my question/concern was that this personal trainer said that when that happens your body will crave food so badly it's almost like a wash because you won't be able to not eat afterwords. Thus burning 600 calories of glycogen and 100 calories of fat in a workout would yield very slow results that could lead to frustration. That the idea was to burn as many fat calories as possible; to work out hard, but not very hard. I thought this might be B.S.

Regardless of where someone's calories are being burned from (sugar or fat) will you not lose basically the same amount of weight if you keep your calorie consumption in check?
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yes it's BS. calories burned throughout the course of of the day is what matters. the fat burning zone has long been a sore spot for personal trainers to grasp their head around and is complete and utter garbage. If you take something home from all this, it should be: your workout if done at the upper intensity levels for both cardiovascular and resistance training will overall yield much better fat loss results vs cardio done in the "fat burning zone"...
 
Beatlesboy said:
... you should work out (cardio) hard, but not very hard
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Huh? Say what?
BigB.gif


Exactly how hard is hard but not too hard?


Beatlesboy said:
... because a bigger percentage of the calories you'll burn are from glycogen, not fat. Doing that makes you crazy hungry and your body will turn to muscle, losing muscle as a result.
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I think we have a misunderstanding of basic physiology here.

Beatlesboy said:
Basically, I want to work out as much as I want without worrying about losing tons of muscle mass.
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Then drag your ass down to the gym first thing in the morning as soon as you get out of bed, before you eat a thing, and do fasted state cardio. Seems to be the in thing these days.

Reason being your glycogen levels are lowest in the morning, so the body has to switch to fat as fuel. So the theory goes. But after 25 minutes or so.

Then you'll be crazy hungry when you're finished and your body will turn to replenishing glycogen with less chance of storing fat, preserving muscle as a result.
 
Your first two quotes were me being the voice of what the personal trainer I talked to told me. Hard vs. Very Hard was described in terms of heart rate. The higher the heart rate the more calories you're burning from glycogen vs. fat (supposedly).
 
Beatlesboy said:
The higher the heart rate the more calories you're burning from glycogen vs. fat (supposedly).
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As long as there is a steady supply of stored glycogen.

Again, if glycogen isn't available as a fuel, then the body has to switch to a secondary source - fat.

Thus the theory of fasted state cardio.

Of course, the body never burns 100% of either fat or carbs. But the fat blend is higher if glycogen is lower.

So the theory goes, as I said.

As someone that's forced himself to drag is ass onto the eliptical at 6 am, I can attest that it sure seems to work! :iagree:
 
it doesn't work. studies prove it doesn't work. calories in throughout the course of the day have many times much greater impact on fat loss. Time of the day is meaningless...
 
Jynus said:
it doesn't work. studies prove it doesn't work. calories in throughout the course of the day have many times much greater impact on fat loss. Time of the day is meaningless...
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Yada, yada, yada.... studies prove it doesn't work.

Quote your sources instead of blanket generalizations - if you have any.

Of course, nothing is black and white.

As I said, you have to find what works for you.

Tom Venuto addressed this question in an article:

Again, as Tom puts it...

"First of all, let me say that the fasted cardio in the morning theory IS controversial... Does morning cardio burn a greater amount of fat than cardio done at other times? Well, the bottom line when evaluating any training or nutritional practice is results - period! I don't care what any "expert" says or what any research study says - I measure my results carefully and if I'm getting results training or eating in a certain manner, I'm going to keep doing it. And so should you. I suggest you base all your decisions about your training and nutrition on results and results alone."

Can't argue with that sound advice.

But back to the question at hand, Tom goes on...

"Although most academic types don't believe in the morning cardio theory, there's plenty of research that supports it. I found it especially interesting that Dr. Mel Siff, Author of Facts and Fallacies of Fitness and moderator of the Supertraining Yahoo forum, included a brief section in his book called "Slim Before Breakfast." He quoted a study lending support to the a.m. cardio theory. Dr. Siff wrote;"

"A study carried out at Kansas State University (Wilcox, Harford & Wedel Medicine & Science in Sports and Exercise, 17:2, 1985), indicates that a kilogram of fat will be oxidized sooner when exercising in the fasted condition in the morning than when doing the same exercise in the afternoon. By measuring respiratory gas exchange, caloric expenditure, and carbohydrate and fatty acid metabolism, these researchers showed that the mass of fat burned during aerobic exercise amounts to 67% of the total energy expenditure achieved when the same exercise is done later in the day or in the fed state."
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So don't give me this "it doesn't work. studies prove it doesn't work" crap.

There's plenty of research to show it does work and there are plenty of people that have tried it and got results.
 
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