Fast Weight Loss Diet Why the "Fat Burning Zone" Is a Myth

[Legolas]

Fast Weight Loss Diet
Why the "Fat Burning Zone" Is a Myth
by Jonny Bowden, M.A., C.N.S.

I want you to do me a favor. I know you're gonna hate it, but please do it anyway. I promise you it'll make life so much simpler, make things so much clearer, and save us so much time in the coming months.

I want you to go back to school with me for a minute, and review some math.

Now, when I teach this stuff to trainers, as soon as they hear "math" their eyes glaze over and they look like a collective herd of deer caught in the headlights of a Mack truck. But, honestly, how are you going to talk sensibly about calories, diets like "40/30/30," percentages of calories from protein, decoding a food label, or anything else along those lines without unfuzzy-ing up some of the basics in the math department?

Which brings me to the area of "fat burning" zones.

See, one of the biggest misunderstandings and "myth-conceptions" in the field of exercise and weight loss has been around the field of fat burning. Aerobic teachers are constantly admonishing their students to work at a slower rate so they can "burn more fat." Almost all cardio equipment in the gym has a "fat burning" program, and we fitness professionals are constantly bombarded with questions from clients about how to get their heart rate in the target "fat burning zone."

The misconceptions come from a basic confusion between percentages and absolute amounts. See, at rest, the body is always burning a mix of fuels. All other things being equal, it doesn't like to burn protein, so that leaves fats and carbohydrates (more technically, fatty acids and glucose). At rest, the "average" person burns about 70 percent fat and 30 percent carbs. As one moves from rest to activity, the percentage of fuel coming from fat decreases and the percentage coming from carbs increases. The more intense the exercise, the more carbs and the less fat in the mix, until you reach the point called the "anaerobic threshold" where you're going at about your intensity limit. At that point, 99 percent or more of your fuel is pure carbohydrate and 1 percent or less is coming from fat.

Now, this situation has led many people to assume that in order to "burn fat" they need to exercise at lower intensities. They're missing the boat. Why? Because while at rest, although a higher percentage of your calories is indeed coming from fat, you are ultimately burning a lower absolute number of calories. At higher intensity exercise, the percentage of calories from fat goes down, true -- but it is a percentage of a significantly higher number.

To illustrate this critical difference, I often ask audiences to picture Ross Perot standing next to me. Then I ask them, "Would you rather have 90 percent of all the money I have in the world, or 3 percent of all the money Mr. Perot over here has?" When they give the obvious answer, I say, "But why? 90 percent is so much higher than 3 percent!"

They get the picture.

So, let's say you're exercising at a fairly low intensity that burns, oh, 100 calories in a half-hour. Let's say that 70 percent of those calories come from fat. Your neighbor, however, is working out much harder, outside the magical "fat burning" zone: She's burning up, say 300 calories in that same half hour, but only 50 percent of those calories are from fat. Now do the math. You're burning a higher percentage of fat, but 70 percent of your 100 calories equals 70 fat calories burned. Your neighbor, on the other hand, is burning a lower percentage of fat, but she has burned up 50 percent of 300 calories, or 150 fat calories, more than twice what you've burned in the same period of time!
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So what do you guys think of this ??

[FireGuy]

Have heard this and went over it a thousand times when people ask this question. First of all, it is true in theory and it's why many people prefer HIIT for their cardio. But....if you are doing your cardio first thing in the morning or after an intense workout with weights you dont have the glycogen stores to use for the other "50%" of the calories. This is especially true if you are dieting and on a restricted calorie diet. In this state you are just begging your body to start breaking down protein (ie, losing muscle) to get through higher intensity cardio sessions. If my goal is to get lean, as in 10% or under I am going to choose the low intensity variety 10 out of 10 times.

[Legolas]

Have heard this and went over it a thousand times when people ask this question. First of all, it is true in theory and it's why many people prefer HIIT for their cardio. But....if you are doing your cardio first thing in the morning or after an intense workout with weights you dont have the glycogen stores to use for the other "50%" of the calories. This is especially true if you are dieting and on a restricted calorie diet. In this state you are just begging your body to start breaking down protein (ie, losing muscle) to get through higher intensity cardio sessions. If my goal is to get lean, as in 10% or under I am going to choose the low intensity variety 10 out of 10 times.

What if ur on steroids ?
Besides when you deplete ur glycogen stores through weight training , ur not depleting the stores in ur leg muscles , ur primary targeting the glycogen stores in the trained muscle , chest lats etc....

[D7M]

from personal experience, I know that low intensity cardio for a longer duration helps me to burn fat and preserve muscle.

So, I'll stick with that.

[magic32]

from personal experience, I know that low intensity cardio for a longer duration helps me to burn fat and preserve muscle.

So, I'll stick with that.

Ahhh, that's precisely the myth he's busting here.

Firstly, the body doesn't discriminate against the release of fat as the "Fat Burning Zone" theory posits, i.e. "Moderate aerobic training better coaxes fat reserves into utilized energy." Like most theories it's founded on sound reasoning, but said reasoning is flawed. Your body doesn't care where the calories come from.

This is a very good post Legolas, though destined to be wrought with controversy. I briefly address this very topic, and approach it mathematically (via formula), along with an easy to understand graphic illustration that measures & compares both 'total calories burned' and 'fat calories burned' by the respective methods namely, moderate and high intensity training in "Total Fitness and the Female Body"...http://www.steroid.com/women_and_steroids.php

Scroll down and click on section #4: IV. AEROBIC/CARDIOVASCULAR EXERCISE.

Nice points FireGuy.

[NewMuscle83]

Ahhh, that's precisely the myth he's busting here.

Firstly, the body doesn't discriminate against the release of fat as the "Fat Burning Zone" theory posits, i.e. "Moderate aerobic training better coaxes fat reserves into utilized energy." Like most theories it's founded on sound reasoning, but said reasoning is flawed.

This is a very good post Legolas, though destined to be wrought with controversy. I briefly address this very topic, and approach it mathematically (via formula), along with an easy to understand graphic illustration that measures & compares both 'total calories burned' and 'fat calories burned' by the respective methods namely, moderate and high intensity training in "Total Fitness and the Female Body"...http://www.steroid.com/women_and_steroids.php

Scroll down and click on section #4: IV. AEROBIC/CARDIOVASCULAR EXERCISE.

Nice points FireGuy.

I see the point they're trying to make..but where is the source for this info?? it's only an illustration made on microsoft paint. Not that i'm disputing it, i'm just simply wondering if there were any actual studies made to determine that LI burns 50% fat calories, and HI burns 40%.

[magic32]

I see the point they're trying to make..but where is the source for this info?? it's only an illustration made on microsoft paint. Not that i'm disputing it, i'm just simply wondering if there were any actual studies made to determine that LI burns 50% fat calories, and HI burns 40%.

Good man!
I like how you think. Anything declared should be supportable, else don't say it!
And as indicated earlier, and reiterated in each of the articles below, it really does come down to simple math:

• http://www.myfooddiary.com/resources..._zone_myth.asp
• http://www.prevention.com/cda/articl...ichele.stanten
• http://www.active.com/triathlon/Arti...rning-Zone.htm
• http://ezinearticles.com/?The-Myth-o...ER!&id=2134778
• http://www.diet.com/dietblogs/read_b...yth&blid=15231

However, for the incredulous mind (myself included), here are a bevy of supporting studies:

1. Achten J, Jeukendrup AE. Relation between plasma lactate concentration and fat oxidation rates over a wide range of exercise intensities. Int J Sports Med. 2004 Jan;25(1):32-7.
   
2. Thompson DL, et al. Substrate use during and following moderate- and low-intensity exercise: implications for weight control. Eur J Appl Physiol Occup Physiol. 1998 Jun;78(1):43-9.
   
3. Phelain JF, et al. Postexercise energy expenditure and substrate oxidation in young women resulting from exercise bouts of different intensity.J Am Coll Nutr. 1997 Apr;16(2):140-6.
   
4. Lee YS. Et al. The effects of various intensities and durations of exercise with and without glucose in milk ingestion on postexercise oxygen consumption. J Sports Med Phys Fitness. 1999 Dec;39(4):341-7.
   
5. Melanson EL, et al. Effect of exercise intensity on 24-h energy expenditure and nutrient oxidation. J Appl Physiol. 2002 Mar;92(3):1045-52.
   
6. Saris WH, Schrauwen P. Substrate oxidation differences between high- and low-intensity exercise are compensated over 24 hours in obese men. Int J Obes Relat Metab Disord. June; 28 (6): 759-65.
   
7. Grediagin A, et al. Exercise intensity does not effect body composition change in untrained, moderately overfat women. J Am Diet Assoc. 1995 Jun;95(6):661-5.
   
8. Mougios V, et al. Does the intensity of an exercise programme modulate body composition changes? Int J Sports Med. 2006 Mar;27(3):178-81.
   
9. Okura T, et al. Effects of exercise intensity on physical fitness and risk factors for coronary heart disease. Obes Res. 2003 Sep;11(9):1131-9.
   
10. Tremblay, et al. Impact of exercise intensity on body fatness and skeletal muscle metabolism. Metabolism. 1994 Jul;43(7):814-8.
    
11. Yoshioka M, et al. Impact of high-intensity exercise on energy expenditure, lipid oxidation and body fatness. Int J Obes Relat Metab Disord. 2001 Mar;25(3):332-9.
    
12. Broeder CE, et al. The effects of either high-intensity resistance or endurance training on resting metabolic rate. Am J Clin Nutr. 1992 Apr;55(4):802-10.
    
13. Gutin B, et al. Effects of exercise intensity on cardiovascular fitness, total body composition, and visceral adiposity of obese adolescents. Am J Clin Nutr. 2002 May;75(5):818-26.

[FireGuy]

I think you are confusing glycogen stores with ATP function.

[makod]

Great Thread.....

So the math states that if you work twice as hard you will burn twice as much. (a nice jog compared vs sprinting)

So this just confirmed what everyone knew?

[FireGuy]

Great Thread.....

So the math states that if you work twice as hard you will burn twice as much. (a nice jog compared vs sprinting)

So this just confirmed what everyone knew?

Actually the thread was about the ratios in which the body burns different macronutrients at different intensities.

[jimmyinkedup]

i think its a good read - EXCEPT when muscle loss is also main concern HI cardio is NOT the best route imo....
Oh and i am also leary of HI Cardio on cycle - JMO

[FireGuy]

i think its a good read - EXCEPT when muscle loss is also main concern HI cardio is NOT the best route imo....
Oh and i am also leary of HI Cardio on cycle - JMO

Was wondering when another voice of reason would be stopping by.

[NewMuscle83]

First he said..

until you reach the point called the "anaerobic threshold" where you're going at about your intensity limit. At that point, 99 percent or more of your fuel is pure carbohydrate and 1 percent or less is coming from fat.

and then he said..

let's say you're exercising at a fairly low intensity that burns, oh, 100 calories in a half-hour. Let's say that 70 percent of those calories come from fat. Your neighbor, however, is working out much harder, outside the magical "fat burning" zone: She's burning up, say 300 calories in that same half hour, but only 50 percent of those calories are from fat.

Wait..wut?

[MuscleScience]

I would take much of what this guys says with a grain of salt. He has a master in psychology and a a PhD in nutrition. Not exactly an exercise science heavy background. Though he makes some valid points, there is much he has left out of the article that few people would catch. For example he mentions Lactate threshold, which is easily measurable on a metabolic cart, it is also easy to measure what energy system a person is in during exercise based on the amount of carbons being blown off during exercise. I still think most experts would agree based on established guide lines that there is a relative fat burning zone. Although I am in the camp that anaerobic exercise is and physiological after burn can be just as effective. To date thought the body of the established literature still supports low intensity long duration cardio for fat burning. Which I think will be amended or changed in the next ten years to some extent.

[Legolas]

so you guys High intensity cardio are more likely to burn carbs and muscles instead of fat and low intensity only fat . Its so confusing everytime you ask somebody this question you get different answers , if you ask 20 people you get about 12 different answers ! my friend is majoring in sports education , and he told me that i have to do low intensity cardio at a heart rate that ranges between 110-120 for more than an hour straight to see results when it comes to fat burning otherwise im burning glycogen and muscle

[FireGuy]

so you guys High intensity cardio are more likely to burn carbs and muscles instead of fat and low intensity only fat . Its so confusing everytime you ask somebody this question you get different answers , if you ask 20 people you get about 12 different answers ! my friend is majoring in sports education , and he told me that i have to do low intensity cardio at a heart rate that ranges between 110-120 for more than an hour straight to see results when it comes to fat burning otherwise im burning glycogen and muscle

High intensity will burn a higher RATIO of carbs but you will still burn fat. I do believe high intensity cardio is effective in certain situations, one being if you are short on time. As I stated earlier if you are on a carb restricted diet and/or sub 10% bodyfat low intensity long duration cardio is the only way to go.

Needing to do it for over an hour to get fat burning results is just plain wrong. As a matter of fact I would say anything over an hour starts becoming counterproductive.

[Maddogdh]

For me I like 20 minutes on the eliptical at a ballistic intenseity to start every workout. I get my heart rate to around 150 and keep it there. I like this and would have to say it works, seems like i'm preserving mass and cutting BF%.

[jfalco]

For me I like 20 minutes on the eliptical at a ballistic intenseity to start every workout. I get my heart rate to around 150 and keep it there. I like this and would have to say it works, seems like i'm preserving mass and cutting BF%.

From a muscle building standpoint, this as as wrong as can be, but if it works for you keep doing it. For me geatting my heart weight up to 150 in 20 minutes would hardly be ballistic. How old are you. 150 should be nowhere near your max heart rate unless you are in pretty rough shape. 20 minutes is pretty long for a warm up and you're cutting into you anabolic window. Cut this down to 7 minutes and you'll get a better work out. I used to do this just to get my blood flowing, but once I stopped, I notice my HR goes up pretty good (I would guess at least 120) as soon as I do my first heavy set and it pretty much stays there, so I don't need to waste the energy on the warm up.

I would say that the big confusion in this thread is based on personal goals and starting point. If you're already in great shape and trying to burn of that last bit of fat w/o loosing any muscle, than low intensity is a must. (I say this mostly because I trust fireguy's opinion).
OTOH if you're fat and you want to loose fat as quickly as possible and are willing to sacrifice muscle in the process, high intensity cardio will get you there quicker as long as you don't hurt yourself.

[Maddogdh]

I hear ya! By know means is 150 max for me ,but i can get it there very quickly often pushing it into the 170 zone. I'm currently 33 pushing 34, 6' & 190. I'm a competitive DH mountainbiker "insane & extreme" anaerobic. I do push my heart rate with weights also. What is a "Anobolic window" ?

[Dougewesq]

I do both so as to not piss of either schools of thought

[NewMuscle83]

Ok, I read all the articles (except #2, it didn't work) and they all are saying the same thing. Basically do HIIT because even that percentage of fat being burned is less than LISS, you are still burning more overall calories, and therefore will burn more fat calories. I understand that logic. My question, however, what if you are on a keto diet? You have little to no carbs, so where is the rest of the energy coming from if fat energy is a small percentage? I would have to assume it's coming from the break down of amino acids in the muscle tissue, no?

[collar]

I have tried both.
I do believe low intensity is the better way to go if you do have time on your hand, which where i think to start dieting and leaning up a little earlier than someone usually does.
Or just to know how their body excatly works.
Second of all i do believe it all depends on the individual how they feel and what they find is working best for them.
I have tried high intensity cardio , for sure i burnt huge amount of calories and fat.
But i also did see myself losing a bit of muscle.
So high intensity i do recommend possibly short term but not over long period of time, cause you can and will lose muscle.

So what i like to do is just to kick start my leaning up faze with high intensity for short period of time, then i switch it to slow.
seems to work fine.

[collar]

Oh and if your goal is to compete or to maintain as much muscle as possible for a show, im sure you want to try to avoid as much as you can to lose some muscle .

So also depends on goal.

[Legolas]

ok so by low intensity the heart rate should be within 110 - 145 ??? and anything higher is high intensity ?? cuz i am 22 years old

[NewMuscle83]

well, I think what they mean by LI is 60-75% of MHR (220-your age). As for HI, I believe they were aiming more at High Intensity Interval Training. As in 2 mins at 80-90% and 2 mins at 60-70%.

[Legolas]

u see ive tried both , i used to make cardio exercises 50-60mins after like 1:30mins weight workout and i lost a lot of fat , but i dont really know if i lost muscle aswell while on low intensity cardio my body fat doesnt really change that quickly so i think its more of lose more fat fast but lose some muscle along or lose some fat slowly while somehow preserving your muscles

[eatrainrest]

u see ive tried both , i used to make cardio exercises 50-60mins after like 1:30mins weight workout and i lost a lot of fat , but i dont really know if i lost muscle aswell while on low intensity cardio my body fat doesnt really change that quickly so i think its more of lose more fat fast but lose some muscle along or lose some fat slowly while somehow preserving your muscles

that too long to do cardio post workout, your body is starving for nutrients stick to 20-30 to preserve muscle and burn fat and add morning session as well LOW ITNENSITY