Against Glycogen Repletion...

[NU_nutrition_TS]

As many of you know [MartinM, Meathead....et al!] I have said that high fat/low carb can and does work for heavy resistance training and muscular development [without carb cycling, loadiing or carb-ups] and have often been challenged to explain why.

Well I've recently come across the blog of one Art De Vaney, PhD, who wrote an essay entitled 'Evolutionary Fitness' which is about to be expanded into a book. Anyway, as well as a scientist he is also an athlete and writes about diet and exercise from a functional and evolutionary perspective. One of those entries pulls together some of the ideas about low carb diets, high intensity resistance training, protein synthesis, muscular development, fat loss and 'cardio':

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Two A Days and More Against "Repletion"

October 5, 2006 04:02 PM

You have seen this before regarding the gene expression that occurs during and after exercise and the effect of muscle glycogen on that expression. My earlier post discussed Pederson's research from a talk she gave (J. Applied Physiology 2005, 99, 6). Now there is more.


First, I used to see some guys at my old gym doing two workouts a day, trying to get bigger. That is not a bad idea so long as you go into the second work out without fully repleting the muscle glycogen drained in the first. It seems that muscle gene expression is up-regulated when muscle is low in glycogen stores. The first work out drains glycogen and sets up better gene expression in the second, but with a big IF. You must not replentish the glycogen between work outs. The problem is that everybody does because they believe in the "window of opportunity" theory of glycogen replentishment and eat and guzzle glucose and protein drinks between work outs to get ready for the next one. This is a big mistake, but you already knew that.


Many genes are activated by exercise in muscle that has low glycogen content; two of them are PGC-1, the gene involved in muscle recovery and PDK4, a regulator of fat oxidation in muscle. These are two good things to have going on and low glycogen is a key that turns them on or up. In addition, RNA and protein synthesis are activated with acute exercise of the sort we Evolutionary Fitters do in muscle that is low in glycogen. We assure low glycogen by exercising on an empty stomach and by not gulping down protein drinks, sports drinks, or over-eating.


Pederson's work also showed that in exercise to failure the leg with the low glycogen stores was the LAST to fail. In that leg, biopsies revealed oxidative genes for mitochondrial enzymes were increased. Less glycogen, more dependance on fat oxidation as a source of energy rather than glycogen. Makes sense. Another hit against the carb loading idea.


And, finally, cytokines, the signalling factors to the immune system and metabolic pathways, are altered by exercise in low glycogen muscle. IL-6 is released and increases fat metabolism (Keller, FASEB Journal 2001).

An evolutionary perspective makes all this seem so natural. Glycogen would be exhausted in an ancestor who either died or escaped. If he escaped, he had to shift energy metabolism to fat since glycogen stores are low after a major, acute effort. Gene expression and cytokine signalling are just some of the things that make that possible.


And you thought you had to do cardio in the "fat burning zone" to burn fat. At least that is what everybody is told. I am beginning to think that almost everything people are told about exercise is wrong. It is time for a new theory or science of exercise and diet. I am trying.

Anyone care to discuss/rip apart/comment?

[Ripped Barbarian]

NU_nutrition_TS, always flying in the face of the convention! (a good thing)

[NU_nutrition_TS]

Well, the forum has got so boring of late...and no movement! To quote Jack Nicholson in Batman: "This town needs an enema!"

[NU_nutrition_TS]

I'm not saying that IL-6 is NOT related to allergic/histaminic response, I'm just puzzled why you brought it up as it is not really mentioned or connected to the article?!

I don't really need to buy the book...the original 26 page essay is free to download and covers most of the basics.

I'm afraid while carbohydrates may be cheaper gram for gram, they are more expensive, comparatively, when it comes to nutrient density. Also, they are not as satiating so you constantly have to graze. I don't know about the author, but I don't feel the need to drop carbs in favour of protein...I use fats instead!

Hmmm! Do I detect an element of 'sour grapes' with regard to academic achievement? I judge the words, not the qualifications of the one speaking them!

[NU_nutrition_TS]

Art De Vaney is 70 years young and still fitter than most men a third his age! To quote from his bio:

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I am Professor Emeritus of Economics at the University of California, Irvine, where I also was a member of the Institute for Mathematical Behavioral Sciences. I published many articles and books on the organization of industry, incentives, decentralization, and complexity in economic systems. Hollywood Economics: How Extreme Uncertainty Shapes the Film Industry (2004) is my latest book.

I am a scientist/athlete and expect to comment on issues of science, uncertainty, the movies, adventure, and fitness as well as other topics from this perspective.

[kp1512]

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I still don't know why you are fixated on the anti-histamines....IL-6 was the last in a list of mechanisms mentioned!

I prefer my carbs low, my protein moderate and my fats high. Fats are a good energy substrate, build hormones, provide bio-available fat-soluble vitamins and give structural integrity to cell membranes as well as being satiating and self-limiting to eat.

Nu

Im with you on this one! I do beleive, as you know, carbs are overated....sadly those that kind of rubbish this whole way of nutriton wont\dont\have given it a chance.

KP

[NU_nutrition_TS]

ABPI=Association of the British Pharmaceutical Industry! Mmm! Sorry to say this, Jules, but the level of understanding you seem to be displaying at the moment only serves to confirm why I have a such a low opinion of Big Pharma and their wares! I would not credit any studies paid for by Big Pharma as having any basis in reality...it's all about selling drugs!

[kp1512]

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glass houses and stones dont mix- pubmed, bmj, various other places can be searched.............as previosuly said author fails to impart full story, hell yeah **** it I MAY BE WRONG because i only know one real side of the equation........but wouldnt chronic suppression of the inflammatory response stunt growth? various threads across web suggesting nsaids impact etc?
i think it is brilliant the amount of lateral thinking and debate that occurs on this board..........not so long ago i welcomed a debate on probably a more contraversial suggestion of prec-contest dieting I had read

Hmm have you had some sort of issue on the board etc?

abpi ? cough!

I agree with the gold standard places you mention, PM, bmj, jcem, etc I have full access to them all but not all do....but its always good to kind of quote things where possible and ref them...as it allows all here to learn.....thats my point.

Each to there own I guess man! adios!

[sendos]

If your main respiritory substrate is fat then surely you'd have a lower propensity to store it in the body as its being used for energy. whereas if carbohydrates are you're main substrate then any fat you do consume will be deposited around the body instead of being used.

[kp1512]

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If your main respiritory substrate is fat then surely you'd have a lower propensity to store it in the body as its being used for energy. whereas if carbohydrates are you're main substrate then any fat you do consume will be deposited around the body instead of being used.

few variables there....insulin and the level of glycogen in the cells......