T Nation

Glucose and Gene Expression

I just read about this, and found it fascinating. If high glucose levels do indeed blunt gene expression after exercise, then I guess most of us are doing PWO nutrition all wrong. Or is the anabolic effect of an insulin surge even more beneficial?
It would be great if JB could comment on this.
This is from Arthurdevany.com:

"Gene Expression and Muscle Glycogen
I said it before and I say it again now: filling your muscles with glycogen is nonsense. I have pointed out how gene expression is altered by your activity and your stores of nutrients, among other things. And I have argued that body builders and runners and others who rush to refill their muscle with glycogen right after a work out are actually turning down the training response.

Now, here is an interesting article that measures gene expression and it shows that it is turned down when your muscles contain a lot of glycogen. You reduce the magnitude of the adaptive response to exercise if you are in a hurry, as so many body builders and runners are, to replenish your glycogen stores. They are not thinking at all about gene signaling and adaptation. They are in the linear thinking mode and must reason in a simple (dumb) inventory framework. Use up the glycogen and refill it right away.

This is one of those non-linearities. If you replace the glycogen right away you turn off the gene expression that builds more muscle and does other complex things in muscle tissue. Note the article speaks of TRANSIENT genetic induction, not a steady state. Inducing transients is the essence of the intermittent approach of Evolutionary Fitness.

The abstract follows… There is something very important about uncoupling protein UCP3 that only I and a few others know about and I may be the only person to incorporate respiratory chain uncoupling in anti-aging model and practice.

Read More ?

Influence of pre-exercise muscle glycogen content on exercise-induced transcriptional regulation of metabolic genes

Henriette Pilegaard *, Charlotte Keller ?, Adam Steensberg ?, J?rn Wulff Helge ?, Bente Klarlund Pedersen ?, Bengt Saltin ? and P. Darrell Neufer ?

The Copenhagen Muscle Research Centre, * The August Krogh Institute, University of Copenhagen, Denmark, ? Department of Infectious Diseases, University of Copenhagen, Denmark, ? Rigshospitalet, University of Copenhagen, Denmark and ? The John B. Pierce Laboratory and Department of Cellular and Molecular Physiology, Yale University, New Haven, CT, USA

Transcription of metabolic genes is transiently induced during recovery from exercise in skeletal muscle of humans. To determine whether pre-exercise muscle glycogen content influences the magnitude and/or duration of this adaptive response, six male subjects performed one-legged cycling exercise to lower muscle glycogen content in one leg and then, the following day, completed 2.5 h low intensity two-legged cycling exercise. Nuclei and mRNA were isolated from biopsies obtained from the vastus lateralis muscle of the control and reduced glycogen (pre-exercise glycogen = 609 ? 47 and 337 ? 33 mmol kg-1 dry weight, respectively) legs before and after 0, 2 and 5 h of recovery. Exercise induced a significant (P < 0.05) increase (2- to 3-fold) in transcription of the pyruvate dehydrogenase kinase 4 (PDK4) and uncoupling protein 3 (UCP3) genes in the reduced glycogen leg only. Although PDK4, lipoprotein lipase (LPL) and hexokinase II (HKII) mRNA were elevated in the reduced glycogen leg before exercise, no consistent difference was found between the two legs in response to exercise. In a second study, six subjects completed two trials (separated by 2 weeks) consisting of 3 h of two-legged knee extensor exercise with either control (398 ? 52 mmol kg-1 dry weight) or low (240 ? 38 mmol kg-1 dry weight) pre-exercise muscle glycogen. Exercise induced a significantly greater increase in PDK4 transcription in the low glycogen (> 6-fold) than in the control (< 3-fold) trial. Induction of PDK4 and UCP3 mRNA in response to exercise was also signficantly higher in the low glycogen (11.4- and 3.5-fold, respectively) than in the control (5.0- and 1.7-fold, respectively) trial. These data indicate that low muscle glycogen content enhances the transcriptional activation of some metabolic genes in response to exercise, raising the possibility that signalling mechanisms sensitive to glycogen content and/or FFA availability may be linked to the transcriptional control of exercise-responsive genes."

While this is interesting, I fail to see the relevance between the posted study abstract and the topic at hand. The idea of PWO is to replenish glycogen stores yes, but where does the study draw anything along the lines of “post-exercise glycogen replenishment reduces rates of gene transcription.” The effect of glucose on gene transcription though is an interesting topic. One thing I thought was quite interesting is that increased consumption of glucose prior to exercises actually turns on transcription for PK. Anyway, the net effect is carb loading actually allows an athlete to produce energy more quickly via glycolysis. Cool stuff.

[quote]Trogdor wrote:
While this is interesting, I fail to see the relevance between the posted study abstract and the topic at hand. The idea of PWO is to replenish glycogen stores yes, but where does the study draw anything along the lines of “post-exercise glycogen replenishment reduces rates of gene transcription.”
[/quote]

Granted, English is not my first language, but it certainly states that low muscle glycogen enhances rates of gene transcription.

“These data indicate that low muscle glycogen content enhances the transcriptional activation of some metabolic genes in response to exercise, raising the possibility that signalling mechanisms sensitive to glycogen content and/or FFA availability may be linked to the transcriptional control of exercise-responsive genes.”

[quote]magnusjs wrote:
Trogdor wrote:
While this is interesting, I fail to see the relevance between the posted study abstract and the topic at hand. The idea of PWO is to replenish glycogen stores yes, but where does the study draw anything along the lines of “post-exercise glycogen replenishment reduces rates of gene transcription.”

Granted, English is not my first language, but it certainly states that low muscle glycogen enhances rates of gene transcription.

“These data indicate that low muscle glycogen content enhances the transcriptional activation of some metabolic genes in response to exercise, raising the possibility that signalling mechanisms sensitive to glycogen content and/or FFA availability may be linked to the transcriptional control of exercise-responsive genes.”
[/quote]

I believe that they are saying that pre-workout low muscle glycogen content enhanches the transcriptional activation. They did not test for anything eles. If they are claiming anything about PWO nutrition, they are making conclusions outside of their study that condradict other research. (Sorry I can’t cite sources right now - other than http://www.cbsnews.com/stories/2006/02/24/health/webmd/main1342839.shtml
which cites the original journal article.)

Holy shit.

That is so bad that I can’t even respond to it right now.

My bad. It doesn’t say anything specifically about the post-workout period.

David Barr:
I’d greatly appreciate your input here when you have the time.

Thanks.

Based on the original idea, I have developed my own winning formula for success: if you want to be rich, give away all of your money. That way you’ll be poor and have a much stronger desire to earn. Just keep giving away money to ensure that the drive to accrue cash is high.

Kinda misses the point, right?

BTW-I would still love to see data showing that rapidly replenishing muscle glycogen turns off genes related to muscle growth. It doesn’t make sense from an evolutionary perspective -which is the perspective that the original author seems to be taking.

Charles Staley has a transcript of an interview with Art DeVany in the Locker Room…
http://www.T-Nation.com/readTopic.do?id=1373291

In the course of the thread, JB comments on some of the aspects treated, among other the genetic expression issue:

[quote]
John M Berardi wrote:
Great interview, Charles and Art!

And while agree with much of it - the 90% that all experts agree on :wink: - there are a few inaccuracies with post workout stuff.

During the workout and immediate post-workout period GH is not blunted by insulin. Simply, the GH response isn’t altered by workout and PW drinks. The data shows that outside of the workout period, this does happen. But within and immediately post, it doesn’t.

So that argument is moot.

As far as the comments re: genetic expression and the fact that pw carbs decrease training response - this is based on theoretical genetic expression research. Yes, a few isolated studies show that there is a genetic impact.

However, ignoring the massive amount of literature showing workout nutrition tends to reproducibly increase performance, training recovery, etc is a mistake.

As I’ve posted in other threads here: spiking insulin often outside of the workout window is a mistake for all but the very skinny, ectomorphic body types as it can lead to fat gain and maybe, somewhere down the line, may harm insulin sensitivity. However the same is not true during and post-workout. The body has excellent insulin sensitivity at this time.

So my lesson is this – live a lower carb lifestyle outside of the workout window.

And if fat loss is your primary goal, perhaps moderate carbs during the workout and after as well (depending on body type).

Yet if muscle gain and performance are your goals, it’s lower/moderate carb outside of the workout window and more carbs during.[/quote]