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So I was reading this artical and found this quote ineresting "The higher the intensity the more you rely on carbohydrates as fuel, the lower the intensity, the larger percentage of fat you will use as fuel."

I believe that I have read that the best way to burn fat is by high intensity training but the article says that low intensity is the best. Which one is it?
 

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Guys like Friel have noted that medium intensity is a good way to burn a lot of fat. High intensity tends to burn glycogen. On top of that, I tend to be more hungry after high intensity. When comparing calories/joules (objective) and hunger (subjective), I seem to be less hungry after long steady state.

I have been using Friel's plan to the best of my ability. I seem to get nice n' lean during the base phase.

Keep in mind that racing involves all sorts of long endurance and intensity. That's why we should probably do both.
 

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You burn more calories with high intensity. Those calories come primarily from carbs.

You burn less calories with low intensity but more of those calories are from fat.

Frankly, it doesn't matter. Burn as many calories as you can, refuel as carefully as you can (running a ~500 cal a day deficit is pretty doable) and you will lose weight.

Simple as that.
 

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Check out Joe Friel's book, The Cyclist's Training Bible, Monique Ryan's book, Sports Nutrition For Endurance Athletes, and even the Biju Thomas/Allen Lim book, Feed Zone Portables, for excellent information on burning fat vs. carbs and exercise.

Yes, the article is correct. WHILE exercising, carbs should be your choice of refueling because your body can only store roughly 2 hour's worth of carbohydrate energy. The body needs carbs to access your fat stores, which are vastly more plentifully stored in our bodies.
 

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You burn more fat / hour at higher intensity but the % of your energy from fat is reduced as more comes from other sources. You can train your body to burning a higher % from fat by riding in middle Zone 2 for longer rides on a regular basis. Also if you start at lower intensity and slowly ramp up after 30 to 45 minutes you will burn a higher % of fuel as fat than if you start riding harder right out of the gate. Ultra Endurance athletes focus on being very efficient at burning fat vs other sources, you can do some google searches on that if you want to learn quite a bi on the topic
 

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You burn more fat / hour at higher intensity but the % of your energy from fat is reduced as more comes from other sources.
Yup. Though the amount of fat burned per hour does not increase that much with increasing intensity.

The main reason behind the "burn fat at lower intensities" is confusion between the AMOUNT of fat burned and PERCENTAGE of fat burned. Simple example: if you're riding easy and burning 400 calories per hour (about 110 watts, 16-17 mph on the flats with no wind) then you'll be getting about 50% of your calories from fat. Up the pace to around 165 watts and 20 mph and now you're getting 33% of your calories from fat (about 200 calories per hour from fat in both cases). Start hammering at 22 mph (800 calories per hour/220 watts) and you're getting about 25% of your calories from fat.

Roughly the same fat burn per hour in all four cases, but radically different "per cent from fat." This leads some people to mistakenly claim that you burn more fat at easier effort. It's because they don't understand math.
 

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Kerry has it mostly right, from what I have read, and from what my trainers and doctors have told me. You don't plateau the amount of fat calories you burn as you increase intensity as his examples suggest, but you do burn a higher percentage of carb calories. But that point is moot. You still burn more calories and that is the key to burning fat. If you have a deficit in caloric intake, the body makes up for it by burning fat.

But here are some other things to consider. Muscle burns fat. the more muscle you have, the more fat you burn. I don't remember off hand but I think I read that you burn something like an additional 25-50 calories a day per pound of muscle you add just doing daily activities. You burn even more calories when exercising those muscles. But low intensity training does not build muscle. High intensity training (think intervals) does build muscle mass and in the long run, this contributes to burning more fat.

Studies also show that the body continues to burn both fat and carb calories for a much longer period after high intensity exercise (particularly intervals) than it does after low intensity exercise.

In actuality, the unfortunate side effect of low intensity exercise is that if that is all you do, then the body learns to burn those calories more efficiently, resulting in less fat burn over time. But still, doing just low intensity exercise is better than no exercise.

If your goal is just to burn fat then the important formula is calories in is less than calories burned. It doesn't matter if they come from fat or carbs when you exercise. If you have a caloric deficit, the body makes up for it by burning fat.

One source for some of the above: The Myth of the Fat-burning Zone | ACTIVE
You can use google to find others.
 

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Kerry has it mostly right, from what I have read, and from what my trainers and doctors have told me. You don't plateau the amount of fat calories you burn as you increase intensity as his examples suggest, but you do burn a higher percentage of carb calories.
Didn't mean to suggest that fat burning was the same at all intensities, as I said in the intro, but of course my examples used the same fat burn per hour number. I was too lazy to look up the actual numbers, but they don't change that much and certainly not nearly as much as the carb burning numbers do. So the point is the same - people get confused about this "go easy to burn fat" stuff because they don't understand that simple math.

To experience this first hand, do a really easy pace and see how many miles you can go without eating anything. It's a big number. Going hard, you're going to start to run low on carbs after 90 minutes.
 

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Didn't mean to suggest that fat burning was the same at all intensities, as I said in the intro, but of course my examples used the same fat burn per hour number. I was too lazy to look up the actual numbers, but they don't change that much and certainly not nearly as much as the carb burning numbers do. So the point is the same - people get confused about this "go easy to burn fat" stuff because they don't understand that simple math.

To experience this first hand, do a really easy pace and see how many miles you can go without eating anything. It's a big number. Going hard, you're going to start to run low on carbs after 90 minutes.
^^^ This. Kerry doesn't have it mostly right, he has it very right as it pertains to the situation, scenario he was replying to. Fiziks, you introduce many nuances that
are really useless in the equation being considered. The go slow burn more fat data is one of the most abused pieces of physiology phenomenon that exists. Is it true? Well, kind of... If you are a body builder cutting 8% to 3% then yes... If you are an incredible fit endurance athlete, cyclist especially, then yes. For 99% of us? No. This is a joke. He is exactly right when he says people don't understand the simple math. I'm glad someone said it. It's simple as hell. In vs out. So simple... All these concoctions... Carbs or protein? Plant based? All completely useless.
 

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I've often wondered about this (fat burning during different types of exercise). I would not consider myself well studied. I get frustrated reading so much contradictory information from supposedly reputable sources.

The consensus in this thread seems to be that you burn the same amount (percentage of calories) of fat during high intensity exercise as you do during low intensity, and I've always believed this to be true. But, in another thread, someone posted a link to an article at "todaysdietician.com" (the article focuses on recovery) that contradicts this.

Postexercise Recovery ? Proper Nutrition Is Key to Refuel, Rehydrate, and Rebuild After Strenuous Workouts

Anaerobic exercise also is fueled almost entirely by carbohydrates, according to Sally Hara, MS, RD, CSSD, CDE, of ProActive Nutrition in Kirkland, Washington. “There isn’t enough oxygen available during anaerobic exercise to use the oxidative pathway necessary to use fat as a fuel,” she says. “So if there’s insufficient carbohydrate available, the body will turn to protein for fuel.
This statement seems fairly definitive, and a little scary. Protein as a fuel source could mean a lot of things. Most of of them aren't good.

This kind of thing is frustrating to me. It would be really nice to have some consensus among the dietitians and nutritionists out there.

Edit: The person quoted in that article seems to be fairly well credentialed. Here is her website

Sally Hara, MS, RDN, CSSD | ProActive Nutrition

Sally Hara, MS, RDN, CSSD





  • [*=left] Registered Dietitian/Nutritionist
    [*=left] Board Certified Specialist in Sports Dietetics
    [*=left]Experienced Diabetes Educator
Sally Hara’s specialties include sports nutrition, eating disorders, diabetes, cardiovascular health, food sensitivities, and nutrition for behavior & mood disorders.
[HR][/HR]EDUCATION

  • Dietetic Internship: University of Washington.
  • Master of Science: Nutrition Science, University of California, Davis
  • Bachelor of Science: Nutrition Science, University of California, Davis
  • Bachelor of Science: Exercise Physiology, University of California, Davis
[HR][/HR]PROFESSIONAL CREDENTIALS

  • Registered Dietitian/Nutritionist (RDN, since 1996)
  • Washington State Certified Dietitian (CD, since 1998)
  • Board Certified Specialist in Sports Dietetics (CSSD; since 2008)
  • Certified Diabetes Educator (CDE; 1998-2015 )
[HR][/HR]PROFESSIONAL AFFILIATIONS

  • Academy of Nutrition and Dietetics (AND)
  • Sports Cardiovascular & Wellness Nutritionists (SCAN) practice group
  • Professionals in Nutrition for Exercise and Sport (PINES)
  • Collegiate & Professional Sports Dietitians Association (CPSDA)
  • International Association of Eating Disorder Professionals (IAEDP)
 

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I could be wrong, but I think you might be miss reading or interpreting what she is saying (or maybe she isn't being clear enough). Everything I have read says there is always oxygen available to burn fat, it's just that a larger percentage comes from burning Glycogen when at higher intensity. As far as burning protein, adequate BCAAs in a recovery drink and / or prior to workout can be somewhat preventing catabolic breakdown of muscle from what I have read.
 

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I've often wondered about this (fat burning during different types of exercise). I would not consider myself well studied. I get frustrated reading so much contradictory information from supposedly reputable sources.
How relevant is anaerobic exercise in cycling?
 

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I've often wondered about this (fat burning during different types of exercise). I would not consider myself well studied. I get frustrated reading so much contradictory information from supposedly reputable sources.

The consensus in this thread seems to be that you burn the same amount (percentage of calories) of fat during high intensity exercise as you do during low intensity, and I've always believed this to be true. But, in another thread, someone posted a link to an article at "todaysdietician.com" (the article focuses on recovery) that contradicts this.

Postexercise Recovery ? Proper Nutrition Is Key to Refuel, Rehydrate, and Rebuild After Strenuous Workouts



This statement seems fairly definitive, and a little scary. Protein as a fuel source could mean a lot of things. Most of of them aren't good.

This kind of thing is frustrating to me. It would be really nice to have some consensus among the dietitians and nutritionists out there.

Edit: The person quoted in that article seems to be fairly well credentialed. Here is her website

Sally Hara, MS, RDN, CSSD | ProActive Nutrition

Sally Hara, MS, RDN, CSSD





  • [*=left] Registered Dietitian/Nutritionist
    [*=left] Board Certified Specialist in Sports Dietetics
    [*=left]Experienced Diabetes Educator
Sally Hara’s specialties include sports nutrition, eating disorders, diabetes, cardiovascular health, food sensitivities, and nutrition for behavior & mood disorders.
[HR][/HR]EDUCATION

  • Dietetic Internship: University of Washington.
  • Master of Science: Nutrition Science, University of California, Davis
  • Bachelor of Science: Nutrition Science, University of California, Davis
  • Bachelor of Science: Exercise Physiology, University of California, Davis
[HR][/HR]PROFESSIONAL CREDENTIALS

  • Registered Dietitian/Nutritionist (RDN, since 1996)
  • Washington State Certified Dietitian (CD, since 1998)
  • Board Certified Specialist in Sports Dietetics (CSSD; since 2008)
  • Certified Diabetes Educator (CDE; 1998-2015 )
[HR][/HR]PROFESSIONAL AFFILIATIONS

  • Academy of Nutrition and Dietetics (AND)
  • Sports Cardiovascular & Wellness Nutritionists (SCAN) practice group
  • Professionals in Nutrition for Exercise and Sport (PINES)
  • Collegiate & Professional Sports Dietitians Association (CPSDA)
  • International Association of Eating Disorder Professionals (IAEDP)
Definately get a copy of Nutrition for Endurance Athletes. I think it's by Monique Ryan? Take your time reading it, I have to re-read sections... But once you really ingest that you will be ckear.
 

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I could be wrong, but I think you might be miss reading or interpreting what she is saying (or maybe she isn't being clear enough). Everything I have read says there is always oxygen available to burn fat, it's just that a larger percentage comes from burning Glycogen when at higher intensity. As far as burning protein, adequate BCAAs in a recovery drink and / or prior to workout can be somewhat preventing catabolic breakdown of muscle from what I have read.
That highlighted section seems to say pretty definitively that you can't burn fat in that state.
 

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How relevant is anaerobic exercise in cycling?
I do interval training quite frequently, and, I'm heavy and live in a hilly area. I can't ride to work without some portion of my ride being anaerobic.

Our local Wednesday group ride is called "Hill Repeat Wednesday". 90 minutes of mostly anaerobic cycling activity.

I'm not suggesting that Anaerobic activity shouldn't ever be done. Far from it. In fact, I'm not saying anything at all, except to point out the contradictions out there. One of the responses to the quote I posted was a reference to a book that (presumably?) has information that contradicts the quote.

In the grand scheme of things, whether I burn carbs, fat, or protein during a relatively small portion of my cycling activity isn't really all that big of a deal. I just thought that quote was interesting.
 

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I do interval training quite frequently, and, I'm heavy and live in a hilly area. I can't ride to work without some portion of my ride being anaerobic.

(...)
90 minutes of mostly anaerobic cycling activity.
I suppose that everybody goes anaerobic a few times when riding, but 90 minutes? That sounds phenomenal to me. (Perhaps I don't understand what anaerobic means here.)
 

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Didn't mean to suggest that fat burning was the same at all intensities, as I said in the intro, but of course my examples used the same fat burn per hour number. I was too lazy to look up the actual numbers, but they don't change that much and certainly not nearly as much as the carb burning numbers do. So the point is the same - people get confused about this "go easy to burn fat" stuff because they don't understand that simple math.

To experience this first hand, do a really easy pace and see how many miles you can go without eating anything. It's a big number. Going hard, you're going to start to run low on carbs after 90 minutes.
^^^ This. Kerry doesn't have it mostly right, he has it very right as it pertains to the situation, scenario he was replying to. Fiziks, you introduce many nuances that
are really useless in the equation being considered. The go slow burn more fat data is one of the most abused pieces of physiology phenomenon that exists. Is it true? Well, kind of... If you are a body builder cutting 8% to 3% then yes... If you are an incredible fit endurance athlete, cyclist especially, then yes. For 99% of us? No. This is a joke. He is exactly right when he says people don't understand the simple math. I'm glad someone said it. It's simple as hell. In vs out. So simple... All these concoctions... Carbs or protein? Plant based? All completely useless.
So I see Kerry agreeing with me and you agreeing with Kerry but completely disagreeing with me. But I see that my critical error was simply responding to the OP's statement without reading the article in question first (the point of the article was basically that fat can't get into the system fast enough to be a useful source of energy when consumed either just prior to or during a long ride in competition, and that carbs were the primary source of energy anyway). And many of the nuances I discussed aren't relevant to the article in question, but are relevant to the OP's question.

From a purely academic point of view, high intensity exercise does not burn much more fat than low intensity exercise WHILE you exercise (but it does burn more).

But, you continue to burn fat and carbs at a higher rate for a much longer period AFTER you finish high intensity exercise than for low intensity exercise, resulting in more fat burned overall and more calories consumed overall.

Does this matter to you? It depends on what your goals are. My goal is to lose weight. So yes, it matters to me. While I don't know what the origin of the fat burning myth is, I've talked to a number of physicians who basically use it to explain to their overweight patients that they don't have to turn themselves inside out to lose weight, that even a moderate amount of mild aerobic exercise (assuming no increase in caloric intake) over a prolonged period of time. In fact, I was on the "patient" end of one of those discussions a few years ago.

I see PBL agreeing with pretty much all of what I *meant* to say. But I think my second to last paragraph should have said:
If your goal is just to lose weight then the important formula is calories in is less than calories burned. It doesn't matter if they come from fat or carbs when you exercise. If you have a caloric deficit, the body makes up for it by burning fat.

Those two words (instead of "burn fat") make a big difference. I should have paid more attention to the words I was using.
 

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How do you reconcile this statement...

fiziks said:
From a purely academic point of view, high intensity exercise does not burn much more fat than low intensity exercise WHILE you exercise (but it does burn more).
With the quote from Sally Hara above?

Anaerobic exercise also is fueled almost entirely by carbohydrates, according to Sally Hara, MS, RD, CSSD, CDE, of ProActive Nutrition in Kirkland, Washington. “There isn’t enough oxygen available during anaerobic exercise to use the oxidative pathway necessary to use fat as a fuel,” she says. “So if there’s insufficient carbohydrate available, the body will turn to protein for fuel".
I'm not arguing, or even taking any sides here. I just see a lot of information posted as fact, and there is just so much contradiction out there.

I certainly don't know, and only have my own very limited personal experiences to go on.
 

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It depends on what you call "high intensity". I would consider anything beyond the fat burning zone to be high intensity, and that includes both aerobic and anaerobic exercise. The key word in your quote from Sally Hara is "anaerobic". Not all high intensity exercise is anaerobic. From a pure time duration point of view, I do much more high intensity aerobic exercise than I do high intensity anaerobic exercise.

Another article: The Fat Burning Zone Myth: Don't Be Fooled - BuiltLean
 

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I do interval training quite frequently, and, I'm heavy and live in a hilly area. I can't ride to work without some portion of my ride being anaerobic.

Our local Wednesday group ride is called "Hill Repeat Wednesday". 90 minutes of mostly anaerobic cycling activity.

I'm not suggesting that Anaerobic activity shouldn't ever be done. Far from it. In fact, I'm not saying anything at all, except to point out the contradictions out there. One of the responses to the quote I posted was a reference to a book that (presumably?) has information that contradicts the quote.

In the grand scheme of things, whether I burn carbs, fat, or protein during a relatively small portion of my cycling activity isn't really all that big of a deal. I just thought that quote was interesting.
You are referring to me and my recommendation to read an excellent source to help you better understand what you are questioning? Why do you presume contradiction? All I'm suggesting is that book, among others, is an excellent and rather comprehensive source of information you appear, by your actions here, to be interested in. Eric Heiden and Max Testa have a similarly excellent book. There are contradictions, but not all are real... The book I suggest will clarify the physiology so you can understand what is and isn't quality information. You really need some baseline level of layman understanding to recognize real and apparent contradictions.

Oh, and I'm not shy, if I am going to contradict you, there will be presuming needed.


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