fat burning zone/cardio zone?

[mooguru1]

I heard someone yesterday saying that if you stay within the "fat burning" heart rate zone, then you are actually burning you body fat........and when you are in the "cardio training" heart rate zone, you are burning up your blood fat, or fat that you may have eaten before you worked out.........what I don't understand is the your heart rate is lower in the "fat burning" zone then the "cardio training" zone.........in the cardio, wouldn't you be doing both? Is this whole heart rate thing accurate? Anyone able to explain this? Thanks!!!!

 

Bianca

[9nines]

First, I am not educated in this field, so below is based on my studies born from personal interest only. Also, teh analysis below might be a little superficial but I am fairly certain the outcome is correct. Oxygen intake has an impact on the different fuel mixture but I have gained no understanding or knowledge in that area.

 

You can think of it as a fuel mixture (blood sugar, stored fat and muscle.) Your body burns all as fuel but at different percentages depending on activity.

 

For example, you always burn blood sugar and stored fat during cardiovascular exercise. The percentage of each changes at different hear rate levels. From studies I have read the so-called 'fat burning zone' is burning around 50% of sugar and 50% of stored fat (below and above that hear rate the percentage of sugar is higher than the percentage of stored fat.)

 

At lower rates, the body is not using much fuel and utilizes more sugar in blood, as that is the normal energy sources and the body is in normal mode at these lower hear rate exercises. The 'fat burning zone' plateaus that to utilize both fairly equally. As you exceed the 'fat burning' heart rate range, the fuel need demands of your body increase rapidly (everything is accelerated) and the percentage of sugar burning goes up fairly high, as that is the most efficient fuel (I assume burning stored fat goes down because it is inefficient and can not keep up with body needs at this point - this is only my guess.)

 

Warning on muscle building: This (much higher heart rate exercising - above 'fat burning zone') is also shown to be detrimental to muscle growth because high heart rate exercises deplete carbohydrate stores (most dense pool in your liver and smaller amounts around all muscles) more quickly. Once depleted, the body will increase the burning of its own muscle for fuel (lose muscle mass.)

[9nines]

Added: you will burn more stored fat at higher intensity (higher hear rate) but will burn much more sugar. This risk of burning much more sugar is depleting your sugar store, in which case you will burn muscle. A likely solution to mitigate muscle burning is consuming simple sugars (sports drink, fruit juice) while exercising.

 

For example, say you are going to exercise at a fairly high heart rate (150+) for 30 minutes. Using estimates on most machines, you might find you are burning 1000 to 1200 calories an hour. So you might burn 600 calories during that thirty minutes. 400 might be sugar (and muscle if you deplete sugar stores.) So drink maybe 200 calories of fruit juice or sports drink as you exercise for the first 15 minutes (sip it during those minutes.) That should give your body enough sugar so you do not burn muscle and you still burn a net 400 calories. That will likely lead to more fat burned during that thirty minutes than if you stayed in the fat zone with no sugar drink.

[mooguru1]

Wow, thanks for all the info! This is exactly what I was looking for! So, if I plan on burning the max amount of stored fat durning my cardio session, I must keep a decent sugar supply to energize my body so it won't burn my muscle. Now, when you do run out of blood sugar, does your body start burning stored bf or does it go for the muscle?

 

I was just reading that your body does burn more calories when you are doing a less intense workout, aka. fat burning zone........but when you go above that to the cardio zone then you beging to burn more calories, which, I guess is the ultimate goal. I do like the idea of sipping a light sugar drink during cardio so that my energy suppyly doesn't run dry! So Thanks for the info 9nines!!

 

Bianca

[9nines]

 

I was just reading that your body does burn more calories when you are doing a less intense workout, aka. fat burning zone........but when you go above that to the cardio zone then you beging to burn more calories, which, I guess is the ultimate goal. I do like the idea of sipping a light sugar drink during cardio so that my energy suppyly doesn't run dry! So Thanks for the info 9nines!!

 

Bianca

 

Clarification: A higher intensity will burn more calories but a lower percentage will be from stored fat - you still will probably burn more stored fat.

 

For example:

 

At moderate intensity and a heart rate of 125, you might be burning 600 calories an hour and 50% are from stored fat and 50% from sugar. At around 150 heart beats per minute, you might be burning 70% sugar and 30% fat but burning a total of 1200 calories per hour. In the latter case, your percentage of total calories burned as fat is lower but you are still burning more fat. The risk now is you are depleting your sugar faster and if you deplete it, you will probably burn muscle for fuel. Drinking some quickly digested sugar (fruit juice, sports drink) during the exercise will help mitigate running out of sugar.

[sionkali]

Hmmmm...now I'm totally confused; I shouldn't be keeping my heart rate so high while doing cardio (usually between 157-177; I have a high resting heart rate)? Does that mean my projected range is not correct? I've also been told not to drink sugary sports drinks while working out because of the number of calories it adds, so I've always just stuck to water - is this idea wrong too?

 

I'm sorry if there's an obvious answer to these questions - gym stuff has me all flustered and confused lately, so I'm probably more likely to ask the "stupid/obvious" questions.

 

Any help would really be appreciated; I have no idea what I should be doing when it comes to the gym anymore.

 

Thanks in advance.

 

Jen

[mooguru1]

Hmmmm...now I'm totally confused; I shouldn't be keeping my heart rate so high while doing cardio (usually between 157-177; I have a high resting heart rate)? Does that mean my projected range is not correct? I've also been told not to drink sugary sports drinks while working out because of the number of calories it adds, so I've always just stuck to water - is this idea wrong too?

 

I'm sorry if there's an obvious answer to these questions - gym stuff has me all flustered and confused lately, so I'm probably more likely to ask the "stupid/obvious" questions.

 

Any help would really be appreciated; I have no idea what I should be doing when it comes to the gym anymore.

 

Thanks in advance.

 

Jen

 

 

 

I would like to know about this stuff too...good question!

[9nines]

Hmmmm...now I'm totally confused; I shouldn't be keeping my heart rate so high while doing cardio (usually between 157-177; I have a high resting heart rate)? Does that mean my projected range is not correct? I've also been told not to drink sugary sports drinks while working out because of the number of calories it adds, so I've always just stuck to water - is this idea wrong too?

 

I'm sorry if there's an obvious answer to these questions - gym stuff has me all flustered and confused lately, so I'm probably more likely to ask the "stupid/obvious" questions.

 

Any help would really be appreciated; I have no idea what I should be doing when it comes to the gym anymore.

 

Thanks in advance.

 

Jen

 

There are different schools of thought. One, keep in "fat burning phase" of 120-130 or the other, HIIT (high intensity interval training) where you go from low rates to high rate intervals. Many swear by HIIT and it is growing in practice. I am trying it but not sure if I can describe the routine well (I do intervals on an elliptical from 130 to 152 to 170 but the 170 is not that tiring so not sure if that is HIIT.) You can search for HIIT to find many sources, on it.

 

On drinking sugary sports drink: that is my own practice to mitigate muscle burning. I also like to exercise at high heart rates and since the science indicates that exercise burns a higher percentage of total fuel as carbohydrates (then muscle if your body depletes the sugar), I want to make sure that I do not run out. I have no weight problem, so I might be over looking weight gain as a concern but even someone wanting to lose stored fat mass, would likely not want to lose muscle mass. Also, I have read numerous reports that advise that highly active people should be more concerned with having enough carbohydrates rather than restricting them. Also, most distance runners take sugary foods, while running.

 

But I would not drink more sugar than you plan to burn. For example, if you use a machine that calculates your calorie burn, drink a sports drink giving you 25 to 30% of that total, maybe. That is what I tend to do. For example, I will drink 130 calories of Gatorade, while doing an exercise, that the machine has estimated is burning 500 to 600 calories.

[Matt]

9nines is essentially correct in all he says, with the possible exception of "taking in no more sugar than you plan to burn". From personal experience as an endurance cyclist, this never worked for me and it's very hard to tell how much you really need. It's always good to go over, IMO. Fat also burns in the fire of carbohydrate, and you also need it to recover.

 

The only other thing I'd like to add (if it hasn't been said before) is that burning fat only (in the 60-70% max heart rate range) has advantages because you aren't breaking down the muscles as much as you are when you get closer to your anaerobic threshold (about 85-90% max heart rate). What this means is that you are burning fat only and your body isn't inclined to have to rebuild which means faster recovery (which makes sense anyway as the intensity is lower). Additionally, going at a higher heart rate will burn more calories, but it cannot be sustained nearly as long, so you can go hours burning fat whereas you can only do minutes at higher intensities.

 

Additionally (and probably most importantly to endurance athletes), training longer at lower, fat-burning heart rates consistently over time creates more mitochondria in your cells and trains the muscles to burn fat rather than carbohydrate which means longer efforts at lower heart rates and overall sustained endurance.

[sionkali]

9nines is essentially correct in all he says, with the possible exception of "taking in no more sugar than you plan to burn". From personal experience as an endurance cyclist, this never worked for me and it's very hard to tell how much you really need. It's always good to go over, IMO. Fat also burns in the fire of carbohydrate, and you also need it to recover.

 

The only other thing I'd like to add (if it hasn't been said before) is that burning fat only (in the 60-70% max heart rate range) has advantages because you aren't breaking down the muscles as much as you are when you get closer to your anaerobic threshold (about 85-90% max heart rate). What this means is that you are burning fat only and your body isn't inclined to have to rebuild which means faster recovery (which makes sense anyway as the intensity is lower). Additionally, going at a higher heart rate will burn more calories, but it cannot be sustained nearly as long, so you can go hours burning fat whereas you can only do minutes at higher intensities.

 

Additionally (and probably most importantly to endurance athletes), training longer at lower, fat-burning heart rates consistently over time creates more mitochondria in your cells and trains the muscles to burn fat rather than carbohydrate which means longer efforts at lower heart rates and overall sustained endurance.

 

Interesting...I'm beginning to think that most everything I've learned in the past about cardio excercise has been either a bit misunderstood or a bit off entirely.

 

Just to make sure I understand correctly, I'll ask - what exactly should I be doing if I'm going to do cardio to burn fat more efficiently? I like doing the elliptical trainer (good on my toe, which I broke recently), so let's use that as an example of what I would be doing regularly - instead of getting my heart rate relatively high for a given period of time (like they told me to do) I should be excercising at 60%-70% of my maximum heart rate (is that the maximum they told me when they gave me a range I should be shooting for?) for a specified amount of time (let's say 30-45 minutes) at least every day.

 

I would guess that this would still give me the cardiovascular benefit as well as the fat burning benefit (my resting heart rate is higher than I would like, so I need to work on getting it down).

 

If anything is confusing let me know and I'll be more than happy to clarify. Excercise has gotten me so frustrated lately, I have no clue what I should or shouldn't be doing. After 12+ weeks of going to the gym at least 3 times a week I have yet to lose a single pound and I think my measurements have actually gone up a smidge; I think I've gained about 4 or 5 pounds total (which isn't a lot, I guess, but it's still a gain instead of a loss).

 

Also, about the sugary drink to use during the first part of a workout (which is something I've never heard of, but might consider trying) - what would be recommended to use?

 

Thanks to anyone who offers information!! Anything at all is greatly appreciated!!

 

Jen

[Matt]

Hi Jen,

 

Any number of common exercises are good for that lower intensity training. Brisk walking is good, slow running or jogging, cycling without intense effort, stationary bike, and others, including the elliptical training at light to moderate effort. As with any fitness, heart rate training zones are relative and based on your current fitness level. Since maximum heart rates generally increase as one reaches a higher level of fitness (and resting heart rates decrease), this zone can vary per individual. My maximum heart rate right now is about 200 beats per minute, so 60-70% puts me around 120-140 bpm for the optimal fat-burning zone.

 

The best way to really know you are in that heart rate zone is to purchase a heart rate monitor. You'll need to determine your maximum heart rate by doing a progressively more intense workout in an effort to reach your maximum. (I wouldn't rely on the "220 minus your age" or any other standardized formula; you should determine what your heart rate is yourself.) Heart rate monitors are so inexpensive and prolific now that I recommend them to anyone doing any kind of endurance sports training who wants to improve. The nice thing about them is that you can set alarms and track your progress on a computer for most of them. Polar has a whole mess of HR monitors, and they have been a standard for athletes for a while, though there are many more now on the market:

 

http://www.polarusa.com/

 

Personally, I think heart rate monitors are an excellent investment--even the low-end ones. However, if getting a heart rate monitor is out of the question, a loose guideline is that 60-70% of your maximum heart rate is the point at which it becomes difficult to talk with someone (or yourself) because you are putting in enough effort to have to breath a bit more than normal. This is just an anecdotal guideline, and not scientific of course. But it gives an indirect measure that you are in that fat-burning zone when your body is trying to get a little more oxygen.

 

Also, my background is in endurance sports (cycling and running), so I'm speaking from this viewpoint, though it applies to anyone who wants to train the body to burn fat, including bodybuilders.

 

As far as the drink, I would pick a general (vegan) electrolyte replacement drink. There are plenty of sports drinks out there, but I'd avoid any that have high-fructose corn syrup as a base, so what I mean here are the general "sports drinks" you find in the supermarket that are advertised as sports drinks or fitness water but are really just a cheap corn syrup base with no real nutritional value. Lack of hydration and loss of electrolytes have been shown to decrease performance, so it's important to maintain the levels during exercise as well as you can. An excellent, vegan-friendly electrolyte drink I recommend is:

 

http://www.clifbar.com/eat/shot_drink.cfm?location=shotdrink

 

(Beware the recovery drink from Clif, though. It contains whey protein and as such cannot be considered vegan.)

 

Good luck!

[crashnburn]

The only other thing I'd like to add (if it hasn't been said before) is that burning fat only (in the 60-70% max heart rate range) has advantages because you aren't breaking down the muscles as much as you are when you get closer to your anaerobic threshold (about 85-90% max heart rate). What this means is that you are burning fat only and your body isn't inclined to have to rebuild which means faster recovery (which makes sense anyway as the intensity is lower). Additionally, going at a higher heart rate will burn more calories, but it cannot be sustained nearly as long, so you can go hours burning fat whereas you can only do minutes at higher intensities.

 

So whats a good way to determine ones HIGH/MAX point in terms of Heart Rate for calculation of the Fat Burning Zone?

 

Should we try a few diff things over diff days and average it out?

 

I'd like to know some good steps I could use.

 

Also, I am guessing this RANGE will change as one becomes more and more active and the resting as well as Max rate change? Do they change.. and how much?

[crashnburn]

I am planning to get one of those Heart Rate meters to check.

[Matt]

Here's a link with a pretty darn good explanation and detail about finding your max heart rate. I always try to run or bike 30 minutes with at least a couple longer efforts during that time until I reach my max, then take my max rate on the heart rate monitor.

 

http://www.howtobefit.com/determine-maximum-heart-rate.htm

[crashnburn]

I am buying one of those Polar F6 HRMs. Time to fix me-self.

[compassionategirl]

Staying in your target heart range/fat burning range is essential for burning fat and not muscle. Your target heart range for burning fat is 65-75% of your max heart rate. TO calculate your range, take the number 220 and subtract your age: that is called your max heart rate. Multiply that number by 65% and 75%. Keep your heart rate between those two numbers while exercising and you will burn fat, not muscle.

 

 

So, let's take my numbers as an example. I am 30 years old so:

 

220 - your age = max heart rate

220 - 30 = 190. So 190 is my max heart rate.

 

Now take your max heart rate and multiply it by 65 % and 75% to get your fat burning range. So, for me that woulld be

 

190 X 65% = 124

190 X 75% = 143

 

So my fat burning range/target range is 124 - 143. If I keep my heart rate between these two numbers while doing cardio, I am burning fat, not muscle.

 

As you get more cardiovascularly fit, you will find that you will need to do a more intense workout to get your heart rate up to your target range. A lot of newbies to fitness always make the mistake of killing themselves on cardio because they see a really fit person running fast on the treadmill. So they think that they need to also run that fast to get that fit. What they dont realize though is that that person's heart rate is probably in their zone. But if somebody who is not cardiovascularly fit tries to run at the same speed, their heart rate will be through the roof which isnt what you want (at least not for a sustained amount of time). SO always let your heart rate monitor be your guide - not what other people seem to do doing on the treadmills!

 

Cardio for fat burning purposes is really all about your heart rate. That is why it really doesnt matter what form of cardio you choose - so long as it can get your heart rate up to where it should be. If waving your arms violently in the air and jumping up and down gets your heart rate to wear it should be, then it doesnt matter from a fat burning perspective if you choose to do that over, say, a treadmill work out. Choose something that is fun for you and can get your heart rate up to where it needs to be - that is the key to good cardio!

 

 

hope that helped.

[9nines]

I wanted to point out something technical because calling a certain zone fat-burning might cause problems (muscle loss.)

 

From fat-burning-zone, I am sure most people would think that implies burning all fat but that is far from the case. At most you might be getting 50% of your energy from fat at the fat burning stage. The other 50% is from sugar and stored sugar and an immaterial amount of muscle.

 

Also, if you deplete that sugar, you are going to then burn a material amount of muscle. So if do a exercise in the fat burning zone for a long time (say an hour) and have not eaten in a while, you are probably going to burn a material amount of muscle because you are risking carbohydrate depletion at which point that other non-fat 50% is going to be from muscle (examples the many skinny fat people you see in gyms - low mass but flabby tone.)

 

Also, that zone name implies you are burning more fat than one would in a higher heart rate more intense workouts. That is not correct. You are meeting a higher percentage of your energy needs from fat in the so-called fat burning zone but the increase in total calories burned from more intense workouts is much higher than the percentage of total calories burned as fat that you lose.

 

For example: on a typical cardiovascular exercise, at 125 heart rate, you might be burning your total fuel as 50% fat and 50% sugar and burning 800 calories an hour, so 400 fat calories an hour. The same exercise at a 160 heart rate, your body might be burning around 35% fat and 65% sugar but burning 1500 calories an hour, so 525 fat calories an hour. (Note: I did not quote those numbers from specific research, as I am just using this to illustrate the math but based on my reading those would be pretty close to point.)

 

The danger is that at higher heart rates, as much more calories are being burned, you have higher risk of depleting carbohydrate stores, at which point you burn a material amount of muscle.

Edited May 19, 2006 by 9nines

[9nines]

 

Cardio for fat burning purposes is really all about your heart rate. That is why it really doesnt matter what form of cardio you choose - so long as it can get your heart rate up to where it should be. If waving your arms violently in the air and jumping up and down gets your heart rate to wear it should be, then it doesnt matter from a fat burning perspective if you choose to do that over, say, a treadmill work out. Choose something that is fun for you and can get your heart rate up to where it needs to be - that is the key to good cardio!

 

 

 

I am not sure that is correct. Many more variables: number and size of muscles involved, resistance, work being done, etc. than just on governing one, heart rate, likely determine the amount of calories burned.

 

For example, you could do a single arm exercise (quickly thrashing it around) and your heart will beat fast to increase the rate of blood flow those single arm muscles need but that might be the same heart rate needed, if your whole body were doing an exercise but the latter would be burning many more calories. In other words, same hear rate but many more calories in one situation than the other.

 

I have read no research on this but it should be easy to prove or disprove. Get a heart rate monitor and do jumping jacks (uses both legs and both arms) then note your heart rate while doing this exercise. Then rest (or on another day) then do same arm movement but no jumping and see if you can easily get to the same hear rate that you achieved from the jumping jacks. If you can easily get to that same heart rate then you know that heart rate is not the single deciding factor because you are clearly not burning as many calories not jumping.

 

The battery is dead on my heart rate strap that my stop-watch monitors, so I can not test but I am curious about the outcome.

 

Anyone mind testing my idea?

[crashnburn]

I will. Soon.

[Matt]

I would be very wary of the "age minus 30" formula to get maximum heart rate. Heart rates vary greatly based on genetics, gender, (and yes) age, etc. The only real way to find max heart rate is to do a test on yourself. Even this is not a real measure as your geneticallly-determined max heart rate--especially if you are not very fit--usually cannot be reached, even at maximum intense effort.

 

My max heart rate is about 205 and I'm 37 years old. Additionally, I have a cyclist friend who is 25 and his max heart rate is 185. So it can vary greatly.

[crashnburn]

Agree with Matt.

 

I am guessing Max HR's can probably change as you start getting more active as well.

 

PS: Whats a good few ways to guage it. I just bought an HRM.

[Sean]

I have a question in regards to this. It's not related to the cardio zone or anything, my question is when is it the best to do cardio? If you do cardio prior to lifting, you'd be burning your stored sugars from what you ate prior to working out right so then you wouldn't be burning as much fat. But if you do cardio after lifting weight you'd already have lactic build up in your muscles which from my understanding would present you from burning fat too. Any opinions or knowledge on this?