60-70% vs 80-90%???

PhotographerOfNature

I understand that when you work out, if you want to burn fat you should stay in the 60-70% range. If you want to improve cardio, stay in the 80-90% range. So, if you are working out in the 80-90% range, how can you not burn fat too? How is it possible to work out and not burn fat when you are burning calories???:huh:

PhotographerOfNature

I understand that when you work out, if you want to burn fat you should stay in the 60-70% range. If you want to improve cardio, stay in the 80-90% range. So, if you are working out in the 80-90% range, how can you not burn fat too? How is it possible to work out and not burn fat when you are burning calories???:huh:

Fitness_Chick

bumpin to keep track of:drinker:

Anna_Banana

Okay, I think that you do actually burn fat in the 80-90, but they want you to know that you have to be between 60 to 70 to start to burn fat, and that you don't improve cardio until you reach 80-90%. I think they mainly state it like that so somebody doesn't think they are improving cardio at the 60-70%range

Anna_Banana

bumpin to keep track of:drinker:

What you couldn't come up with any thing to say about this?:bigsmile:

Poison5119

I got this excerpt from http://yourtotalhealth.ivillage.com/diet-fitness/fat-burning-zone-lets-do-math.html

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.

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!



From what I gather, you are still burning fat calories, but the percentages change a little. It is very confusing. Remember when they said that you didn't start burning fat calories until you'd been exercising for at least 20 minutes, THEN the cals would start to burn? That was wrong.
It would seem that all the percentages refer to is that you don't start burning calories until you're in the 60-70% zone of heart rate.

Fitness_Chick

bumpin to keep track of:drinker:

What you couldn't come up with any thing to say about this?:bigsmile:

I offered a bit of water!!:laugh: I just wanted it to go into 'my topics' to catch up on later MISSY!:grumble: :flowerforyou:

Anna_Banana

bumpin to keep track of:drinker:

What you couldn't come up with any thing to say about this?:bigsmile:

I offered a bit of water!!:laugh: I just wanted it to go into 'my topics' to catch up on later MISSY!:grumble: :flowerforyou:

Got it. It was a good question. I think I vote for Russia's answer so far.

psyknife

The difference is not necessarily simply a percentage... as the percentage will be different depending on your current fitness level. If you are really fit you may be able to work up to 80% and still utilize fat stores... but if you are unfit then you may not be able to get higher than 65%.
It's actually about working in your aerobic zone as opposed to your anaerobic zone.

When you are exercising in your aerobic zone your body is utilizing oxygen, and when using this energy system, the main suppliers of energy include glucose and fatty acids.
However, when you get up too high and get into an anaerobic zone you stop utilizing fat and your body relies on glucose and creatine phosphate to produce it's energy... though it's not good to stay in this zone for a prolonged period of time because it results in build-ups of lactic acid and fatigue.

So, the key... stay in your aerobic zone.

If you really want to research you can do searches about ATP production, as well as "aerobic" and "anaerobic" :drinker:

PhotographerOfNature

Thank you! I have contemplated that everytime I exercise. I try to stay in the 60-70% zone and then I notice that it went above, then I'm asking myself, how can I not be burning fat if I'm working out this hard??? So, thanks for shedding light on it.