Sorry to hear you are sick, Sexy PL Matt. Hope you feel better soon.

BTW, I agree with CC and sue ... this is not nonsense and it's very interesting!

Thanks for the well-wishes.

I am mostly just tired right now, but out of the worst of it.

Matt - glad to hear you are on the mend.

Glad to hear it, Matt!

Hi Everyone: I sent the this thread over to Dr. Sears and he decided to comment directly. He's traveling quite a bit right now so I can't say that he will be able to engage in too much back and forth on the forums. I've cut and pasted his email reply to the ATP threads. Here it is:

FROM DR. BARRY SEARS:
“ I have read with great interest the various discussions in the forums about dietary calories and ATP production. Since biochemistry is much more complex than many realize, so let me provide a short overview. First dietary calories are defined as the amount of energy released in converting a carbon containing compound (glucose, fat or protein) into CO2 and H20 in a combustion chamber. Theoretically, those calories can be made into chemical energy (ATP). However, the biochemistry is more complex. To convert glucose into ATP requires three distinct biochemical steps: (1) the breakdown of glucose into pyruvate, (2) the conversion of pyruvate into acetyl CoA via the Krebs cycle (the greatest fear of any medical student), and (3) the conversion of products of the Krebs cycle (NADH and FADH2) into their precursors (NAD and FAD) in the electron transport chain of the mitochrondria thereby generating ATP. It is in the last step that most of the ATP is formed from glucose. If everything is working smoothly (active enzymes, high levels of oxygen, not taking into account the amount of energy require to break bonds of dietary carbohydrate for absorportion, etc), then 1 molecule of glucose could generate 36 molecules of ATP. The key is the Krebs cycle since it operates on any two-carbon fragment in the form of acetyl-CoA. Glucose has 3 such 2-carbon fragments. A typical fatty has 9 such 2-carbon fragments (assuming 18 carbon atoms per fatty acid molecule). Without going into nuances such beta oxidation in peroxisomes, it means that a typical fatty acid molecule can generate 3 times more ATP than a glucose molecule on a gram basis. This is where I get my 3 times greater ATP production from a gram of fat compared to a gram of carbohydrate. If one wishes to convert this to ATP production per dietary calorie, then you would divide 3 by 2.25 (9 calories per gram of fat divided by 4 calories per gram of carbohydrate). So on a dietary calorie basis, one calorie of fat should produce 33% more ATP than one calorie of carbohydrate. This still makes fat high octane fuel compared to glucose even when comparing calories to calories. Considering that the body can store only limited amount of glucose as glycogen compared to unlimited amounts of fat, the amount of total energy available to humans to make ATP from fat is massive compared to that from glucose."

- Dr. Barry Sears

Thank you, Steve!

Yes, it is a bit confusing, would almost have to be a medical student or biochem in order to really understand it all. Probaby why many of us just take it for face value!

Please tell Barry that we really do appreciate his response, and that sometimes it would be helpful for forum members to have more opportunity to interact.

Thank you Steve. This is interesting, because it does conflict with 2 or 3 biochemistry textbooks I looked at which indicate that the ratio between ATP that can be produced is the same as the ratio between calories. I will be interested to see if Dr. Sears joins the discussion when he is done traveling and can explain the discrepancy.

Yes, it would be helpful to have more discussion.

I seem to get two different numbers for how much ATP is generated from oxidative glycolysis. Some sources say 36 ATP and some say 38 (and I found one that said 39) and I don't understand enough biochemistry (or really any) to know why there is a discrepancy between those numbers.

As far as ATP production from fat, apparently (from what I can tell) the amount of ATP that can be produced varies with the type of fat, because some fats have longer chains than others. I am lead to believe from what I have read, that the fats in human beings are triglycerides. I have seen varying amounts of ATP production depending on which type of fat is used. A recent search I did for ATP production from Beta Oxidation shows a range of between 106-129 ATP. I read another source that estimates that based on the average make up of fat in the human body, 138 ATP can be produced (which, if that is correct and the other numbers are correct, would mean that almost 4x as much ATP can be produced from fat as from carbohydrate sources).

I gotta say that after reading all of this stuff, my head is swimming and I am beyond confused.

Do you think we are over our heads in this? LOL!

So, if Sears is right (and from what you posted, he may have even underestimated it), then where does that leave us with regard to athletes and their energy source?

If athletes can get 3-4x the ATP from fat, then do they really need additional calories, as was discussed? Or, would you think that the Zone IS providing adequate energy supply from from fat?

Personally, I can't speak about what type of fat produces more ATP, but I know that Sears advocates for monounsaturated sources.

Assuming that athletes can get 3x the ATP from fat sources as from carb sources, and considering the fact that fat has about 2.5x the amount of calories, that would mean that fat is 20% more efficient than carbs.

So, if we take someone with daily calorie requirements of 3,200 calories, and assume that eating a Zone diet without any additional fat blocks provides 2,000 calories, that means that I supposed the 1,200 calories short fall could be met by eating 1,000 calories of fat, I suppose.

So, the upshot is that while it may make a difference of a few hundred calories, athletes still need more calories/energy than is provided by meals made up of 1 block each of fat + carbs + protein (at 1 g/lb.)

Whew - thought I was confused before. This is really interesting stuff. It will be interesting to hear about the discrepancies that you found Matt. However I agree, that more total calories would still be needed by the high performance athlete.

Going back to the basic zone principles:

Assuming that the athlete is taking in enough protein to meet their needs, then it would also be assumed that the carbohydrate intake is adequate, as well (keep in mind the protein/carb ratio of 0.6-1.0, there is some leeway in the zone). Then, at this point, it isn't about eating more fat to reach a caloric goal. It is about fine-tuning the diet for the sake of performance. Since it is assumed that fat would produce 3-4x as much ATP as carb, then it would stand to reason that the caloric needs are lower.

So, it sounds to me that an athlete would go through the same steps as anyone to fine-tune and adjust their diet according to LBM, hormonal control, and fat adjustments. The thing that differs is that I think there is potential for the athlete to have more radical changes than a less active person.

I like to keep in mind that the human body varies from one to another, and we all don't operate under the same exact mathematical formula.

Matt!

Glad you were able to gain clarification by contacting Zone Labs!

I read the first Zone book 7 or 8 years ago. And remember that part about a marathon requiring 2000 calories. So the average athlete with 5-10% body fat could run a dozen marathons. But it doesn't happen in the real world, only on the chalkboard. I know because I've run over 40 marathons. I've run marathons while in ketosis, the state of not having any stored carbs (glycogen) available. The problem as I see it is the krebs cycle requires a small amount of sugar to keep spinning. "Fat burns in a carb flame"

Running slowly needs less sugar to augment the krebs cycle than sprinting does. Heart rate determines how much sugar is needed. Training reduces the amount of sugar required. That's how the Kenyans can run marathons below a 5:00 pace.

When you are out of glycogen--ketosis--the body goes into gluconeogenesis. That's when muscle tissue is catabolized to make sugar. So you can never get to the point of burning 100% fat. Running with a 100% fat meal in the stomach won't work. I know, I tried it with dismal results. The body still requires glucose for Krebs to work efficiently.

As I've gotten older and slower, I've moved on to ultras: 50 to 100 mile races. Because it's an even slower pace, even less sugar is needed but it's needed nonetheless. Carb and protein each have 4 calories per gram while fat has nine cals per gram. So on the chalkboard fat has more than double the potential energy of either carb or protein. But that doesn't translate into more or better ATP.

I've come to realize I need to lift weights. I was an 1100-pound powerlifter when I was a kid. I quit lifting sometime in the college years and never went back, prefering to run for health. A couple days ago I tried some pushups and found I could only to 30. 30! Lifting weights, at least upper body weights, doesn't speed up the heart much so it's essentially a fat-burning exercise. It kills me to have to spend time in a gym when the weather is perfect for running right now.

kevin

Hi kevin?

Just wondering. Have you run marathons in the Zone (both training and the event)? My husband and daughters all do and have done great (both daughters are adults and have run multiple marathons each).

I've done a lot of race-training in the zone. I've tried to use zone bars for 30 mile training runs and always run out of energy. Where the zone has done the most for me, it's that I can finish a four-six hour training run and not be dead for the rest of the day. For races I use what's on the race tables, mainly cookies or potato chips. I've experimented with adding soy protein to energy drinks. I wear a camelback that holds about three liters of fluid. That keeps me going a bit longer or further. Maybe my age is a factor. I turned 52 this year. I did my first marathon in 1986.

kevin

Thanks for the extra info. Not sure what it is in your case, but my husband's 59, last marathon he was 58, so age doesn't seem to be a factor for him (that's my son in the photo, not my husband!). None of my family members eat during the event, just drink water for hydration.

Kevin, Matt, Sue... (and anyone else interested)

I have copied the last statement from an article that was written for elite athletes and is posted in the Fitness section of this website:
----------------------------------------------------------------------
Eating in “The Zone”

The team’s anti-inflammatory meal plan originates from ‘The Zone’ eating plan but with modifications for an athletic lifestyle.

Concentrating during the day on low-glycaemic foods, that are also low on the inflammatory list, and high-glycaemic foods during training, they get the perfect mix for energy and recovery.

As Rabin himself says: “When there is often such a small margin between winning and losing, a diet such as this could make the difference.”

Aiming to get the best diet for both performance and long-term health, this team appear to be receiving world-class nutritional support.

You can find out more about ‘The Zone Diet’ at www.zonediet.com, but ensure you insert energy-providing high-glycaemic foods before, during the immediately after training.
------------------------------------------------------------------------

I am having a hard time with this thread, seems to bounce from one side to the other as far as what is appropriate for elite athletes (not that I am anywhere close to that level of performance-LOL). The above article certainly seems to be suggesting that it IS appropriate and necessary to consume some high glycemic foods. This, according to the article, is what will keep an athlete "in the Zone".

Here is the link to the full article:
http://www.zonediet.com/FITNESS/Eli...fault.aspx

Good find CC!

This article does seem to support (rather strongly) what I was writing about before with regard to in-training and immediate post-training nutrition (i.e., high GI carbs + protein + BCAAs). In fact, what is suggested by this article is what I do -- I eat balanced meals with low GI high quality carbs for almost all of my meals... but my immediately pre-workout, during workout, and after workout nutrition is quite different. Also, looking at articles appearing on this site regarding what endurance cyclists actually do during the course of their race, it sure looks like they are doing the exact same thing I am -- high GI carbs + protein (there was no mention of them taking BCAAs).

I will say this... I am not entirely sold on the calorie v. ATP issue. I still haven't heard a response to my e-mail, and while Dr. Sears did respond, there are some discrepancies between various bio-chemistry sources regarding the ATP production values for stored body fat. I have found 2-3 sources saying that the ATP production from stored body fat is about the same ratio as the ratio between calories, and I have found several sources (including Dr. Sears) saying that the ratio is about 20%+ higher for the ATP yield as compared with the caloric yield.

I do no know what to make of these discrepancies, other than to say, "I really don't know what the answer is."

However, I do know enough to know that what Kevin is saying is correct about fat burning in a carbohydrate fire and that when muscle and liver glycogen levels are depleted, performance drops off quite starkly. Carbohydrate sources are the preferred fuel for athletic activities. So, in that sense, regardless of the ATP v. Calorie issue, carbs are absolutely necessary for peak athletic performance simply because your body cannot access enough fat and cannot access it quickly enough to supply the muscles with the ATP they need for continued top level performance. In this sense... carbs are actually high-octane fuel, not stored body fat.

Muscle glycogen is the fastest and most accessible fuel to be converted to ATP/CP if you are engaged in athletics of any modest level of intensity -- even if you are training aerobically as opposed to anaerobically. When you are not training, what your body uses for fuel is flip-flopped, and fat is the preferred energy source.

CC:

I read that article you linked to, and I note that they actually DO mention the use of amino acids as part of the during competition and post-training meal. In fact, here is the meal they use:

1 cup of sushi rice cooked
3 eggs, scrambled and cooked in olive oil
Bacon or Ham (add all together and mix)
Other ingredients as desired, selected from:
Parmesan
Liquid Amino’s
Salt
Soy Sauce
Honey
Fruit

This IS a high GI + protein meal (and adds BCAAs if desired). This jibes fairly closely with what I have suggested on this site. It makes me feel a bit of justification to see that others have approached the conundrum of training/competition nutrition in the Zone in the same way I have.

Yes.

Even though this thread was more about ATP from fat vs. glucose, I think the point is very clear to me that these athletes NEEDED a high GL meal. To me, it is contradictory to the point that Barry was making about using fat as the fuel.

Of course, maybe we are talking about 2 different situations: running a marathon for the sake of running it vs. winning it. There is a big difference. Running for the sake of running takes "endurance", but running for the sake of winning may take more "power".

CC - you are right about endurance vs. endurance with power. Not all weight workouts or cardio sessions are created equal.

And, I was hoping that it would explain why Sue's family can run a marathon on water alone, while other racers who practice the Zone would need a glycemic boost.

From Matthew:

Quote:
I read that article you linked to, and I note that they actually DO mention the use of amino acids as part of the during competition and post-training meal. In fact, here is the meal they use:

1 cup of sushi rice cooked
3 eggs, scrambled and cooked in olive oil
Bacon or Ham (add all together and mix)
Other ingredients as desired, selected from:
Parmesan
Liquid Amino’s
Salt
Soy Sauce
Honey
Fruit
Unquote.

I never cook with Olive Oil and I never eat Soy Sauce!