I'm a Gear Idiot

[SadieKate]

and burns fat - spinning burns more fat than muscling.

Burns more fat? Not necessarily. Your percentage of fat per calories burned may be higher, but as your intensity of effort goes way up the fat amount may stay the same and other fuel sources are also burned. Higher intensity burns more calories but a lower percentage of fat, but not necessarily less fat as a fuel.

[laughlaugh18]

This thread's been really helpful for me, too, although when I try to apply it while on my bike, my brain goes ka-phooey. It all seems bass-ackwards to me - or at least mutually inconsistent - on the front chainring, bigger is harder, but on the rear cog, bigger is easier. For the time being I'm still relying on the nice little numbers on my shifters, where a little number always means easier (which I have to admit is usually my goal, given my beginner's fitness level!)

[Eaglewalker]

Your percentage of fat per calories burned may be higher, but as your intensity of effort goes way up the fat amount may stay the same and other fuel sources are also burned. Higher intensity burns more calories but a lower percentage of fat, but not necessarily less fat as a fuel.

I'm sorry -- say what? I'm not understanding this in English; could you do it in numbers, please?

The higher spin rate and increased respiration rate is especially good for me because I have a lung thingy (both parents smoked [smoking killed my mom, my aunt, and my grandmother], and then we moved to the smoggiest town in Southern California. In this situation, one child in four will have some kind of lung problem, and I'm the statistic -- chronic bronchitis and reduced lung capacity, so anything that builds capacity is A Good Thing.) But I don't get the more fat/less fat thing -- I need a concrete example, with numbers, please? (Sorry again, but I am a nerd by profession and drive my friends nutty.)

[Nanci]

The bigger chain ring (in the front) is harder to pedal, so you use it when you are riding in the easiest conditions- flat or downhill. The smallest chain ring in the front is the easiest to pedal, so you use it when the pedaling is the hardest- steeper hills.

Just remember that moving the chain toward the bike, either in front or back, makes it easier.

Nanci

[SadieKate]

I'm not an exercise physiologist so I deal in concepts only, but I pulled out an article I have from a Sally Edwards' presentation I attended several years ago to get some numbers. For more precise info, read any good books on training or heart monitor books. www.heartzones.com

Here goes for zones 1-3 (of 5 and where you spend the most time):

Zone #/% Max HR/% Fat Cals/% Carb Cals/% Protein Cals/Cals burned in 30 mins

Zone 1 / 50-60 / 70-85 / 10-25 / 5 / >180
Zone 2 / 60-70 / 50-70 / 25-50 / 5 / >240
Zone 3 / 70-80 / 40-60 / 50-85 / 5 / >330

If you do the math, you will see that the number of fat calories burned is approximately the same and even a little higher in zone 3, but the total calories burned goes up. The calories of fat as a percentage go down but not the actual amount of fat burned.

The fat burning capacity of individuals varies widely, but these are some averages. Burning capacity is based on unique physiology, fitness, dietary habits, frequency and time of eating.

[Eaglewalker]

Okay. I'm going to try to translate this as I understand it; somebody tell me if I get it wrong.

The body powers itself by burning available fuel (carbohydrates, stored in the blood as glucose[?]) and by converting stored fat into available fuel and then burning that. Any available fuel that is not burned is stored as fat.

The fuel usage continues at a given ratio (available fuel/stored fuel). This ratio varies, depending on the person. As the heart rate increases (presumably in response to increased activity), the fuel burn increases, the demand on available fuel increases, and so the ratio changes. Wild guess: the body can't convert fat quickly enough to meet the demand, hence the need for increased carbohydrate intake to avoid depleting blood sugar? This would explain why the number of fat calories burned does not increase dramatically -- it can't, because the conversion process can't speed up dramatically.

I do wonder about the third line on that chart, though. The math doesn't work -- is that a typo?

40% fat + 5% protein + 50%-85% carb = 95%-130%; that's okay, because the possible sums include the 100% that the numbers are supposed to add up to. However,

60% fat + 5% protein + 50%-85% carb = 115%-150%; 100% is not a possible solution to that equation, no matter how you slice it. Something is wrong somewhere.

[SadieKate]

I don't understand why you are doing the math with an absolute number for fat and a range for carbs. Each has a range. On the third line, the fat can be as long as 40%.

[Eaglewalker]

I don't understand why you are doing the math with an absolute number for fat and a range for carbs.

I'm doing the low end of the fat range and the high end of the fat range to determine whether the range as a whole is valid. It isn't. For the math to work, the percentage of fat + the percentage of carbs + the percentage of protein must = 100. If the equation works for the lowest number in the first range AND the highest number in the first range, then it works for all numbers within the range, and the range is valid.

The math works for the low end of the fat range, because 40% (fat) + 55% (carb) + 5% (protein) = 100%. 55 is within the range for carbs (greater than 50, less than 85).

It doesn't work for the high end, because no matter what carb number you chose from within the given range, the result is always greater than 100.

If the maximum fat percentage is 60, then the minimum carb range cannot be greater than 35 (because we still have to add 5% protein). Conversely, if the minimum carb percentage is 50, then the maximum fat percentage cannot be greater than 45.

Therefore, either the high end of the fat range is wrong, or the low end of the carbohydrate range is wrong.

The numbers tie out in Zones 1 & 2, but not in Zone 3.

[doc]

Eagle, you are correct about the math. BUT, the calculations refer to what you are burning at the moment of exercise. You do NOT lose more weight by exercising in the aerobic range only. That is a commonly held misconception. There are very good and important reasons to exercise in an aerobic fashion, but NOT because it increases fat burned. The more total calories you burn - whether protein, fat or carb - the more calories you burn. Period. Then it's up to you whether you eat fewer calories than burned or not.

If you eat fewer calories than you have burned, you will lose fat. Assuming you exercised for 1 hour, during the remaining 23 hours of that day your body returns itself to equilibrium. Meaning it tries to replenish glycogen stores, fat stores and build muscle. HOWEVER, if you take in fewer calories than you expend, your body will choose to build muscle, replenish glycogen, and only store fat if calories in any form are left over. So, you will not be burning the fat during the exercise, but your body will be sacrificing fat later (yippee) for other things and therefore you will have the same outcome as burning more fat.

[SadieKate]

I don't know. Maybe Sally Edwards has a typo in her article. Read her books, go to her website, email her. All I care about is the concept which seems to be a universal agreement among trainers. Read Joel Friel. He says the same thing but didn't put the numbers to it which you asked for.

The whole point is that you can burn just as much fat at higher intensity efforts. There was a whole era when we were taught not to get above a certain level because it took you out of the fat burning zone. A bunch of people think that if you can't hold a conversation while working out that you aren't burning fat. Not true. This low level only means that the percentage of fat per calories burned is high and that you can sustain the workout for a long time. These same people that won't push above this level of effort are also the ones that never get faster.

[Adventure Girl]

There was a whole era when we were taught not to get above a certain level because it took you out of the fat burning zone. A bunch of people think that if you can't hold a conversation while working out that you aren't burning fat. Not true.

I never bought that concept! I remember having discussions (arguments?) with aerobics instructors and trainers in the late 80's - early 90's. It just wasn't/isn't logical.

[SadieKate]

I know, I know. Where there is oxygen there is burning fat.

[doc]

A bunch of people think that if you can't hold a conversation while working out that you aren't burning fat. Not true. This low level only means that the percentage of fat per calories burned is high and that you can sustain the workout for a long time. These same people that won't push above this level of effort are also the ones that never get faster.

Exactly!
The one thing they were correct about is that if you cannot hold a conversation you are exercising using anaerobic energy. If you can talk, you are still completely aerobic. Good to know if you don't own a heart monitor because it is very accurate.

[Eaglewalker]

Eagle, you are correct about the math. BUT, the calculations refer to what you are burning at the moment of exercise.

I was just trying to understand the calculations as given, being that I am a curious person (and fussy about math). I ride for the joy of it, fat or no fat. The gear issue on which this topic started got to the high rotation rate as recommended, which (see my earlier post) I discovered increases my respiration rate, so I seem to be getting more aerobic exercise with the low resistance/high rotation than by moving myself along by the power of my mighty haunches. And that presumably will lead to increased lung capacity, which again will be personally beneficial.

Slim is a nice-to-have; healthy lungs are a necessity.

[laughlaugh18]

Just remember that moving the chain toward the bike, either in front or back, makes it easier.

Nanci

Thanks - that's the easiest-to-remember explanation I've seen yet!