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Post exercise drinks and meals again

May 7, 2005 05:06 PM

As I often say, the purpose of exercise is hormone drive and neural and muscle adaptation. You want to enhance your insulin sensitivity because much of modern life is almost an assault on it. Example: my wife was looking to buy some three bean salad. Sounds healthy alright. But, she looked at the label and each serving had over 60 grams of sugar. What a travesty; here is a putatively healthy dish slathered in sugar. All of you will have similar stories to tell.

After exercise, gene expression upregulates GLUT 4 and insulin sensitivity is dramatically enhanced. What happens when you ingest a high CHO meal or drink? You shut down this enhanced sensitivity. Then why bother with the exercise? The movement is good, but the important benefits are the hormone drives you set in motion.

Below is the abstract from is another small experiment, but a good one, that shows what happens to GLUT 4 when you consume high CHO after exercise.

I am slightly perplexed at the interest and comment on this topic; it must be that many have tried to read the magazines and research and have fallen for the party line on this topic. I repeat: there is no reason to consume high (and simple) CHO drinks or meals after exercise. There are many reasons not to do so. This study shows the sugar was taken up by the muscle within 3 hours, but the insulin sensitivity (as measured by GLUT 4) was diminished. This is further evidence that the glycogen stores are a key to insulin sensitivity and the mechanism operates through the GLUT 4 and HK pathways, as modulated by gene expression.

As I think more about it, I realize that most advice is for you to refill your depleted glycogen (why, are you going to drop dead or bonk?). The contrary is actually true. You want to deplete your glycogen stores. They will fill up in plenty of time for your next session and you will be leaner and stronger and far more healthy if you operate this way. Forget the marathoners and others who exhaust themselves. They are not a much more healthy model than bodybuilders.

A worse problem is that many people who do not exercise still feel some need to refill their (non-empty) muscle glycogen as though they are emulating some athlete who may have a real reason to do so. It bothers me when a young person tells me he is drinking X-aid because he needs to replentish his glycogen. It is a mark of some sophistication, yet it is completely wrong for a young person to be set onto the path of reduced insulin sensitivity through the popularization of this erroneous and damaging view.

J Nutr Biochem. 2005 May;16(5):267-71. Related Articles, Links

Effect of postexercise carbohydrate supplementation on glucose uptake-associated gene expression in the human skeletal muscle.

Cheng IS, Lee NY, Liu KL, Liao SF, Huang CH, Kuo CH.

Department of Nutrition and Food Sciences, Fu-Jen Catholic University, Taipei, Taiwan 242, ROC; Chungtai Institute of Health Sciences and Technology, Taipei, Taiwan 406, ROC.

We previously found that the exercise-induced elevation in GLUT4 mRNA of rat muscle can be rapidly down-regulated when glucose is given immediately following exercise. The purpose of this study was to determine the effect of postexercise carbohydrate diet on GLUT4 and hexokinase (HK) II mRNA levels in the human skeletal muscle. Eight untrained male subjects (age, 20.7+/-3.1 years) exercised for 60 min on a cycle ergometer at a 70-75% maximal oxygen consumption. The postexercise dietary treatment was performed in a crossover design. Immediately after the exercise, a diet with 70% carbohydrate content (1 g per kilogram of body weight; 356+/-19.8 kcal) was given to half of the subjects (eaten in 10 min) followed by a 3-h recovery, while the control subjects remained unfed for 3 h. Biopsies were performed on the deep portion of the vastus lateralis muscle of all subjects immediately after the exercise and 3 h after the carbohydrate ingestion. Blood glucose and serum insulin concentrations were measured every 30 min for 3 h. At the end of the 3-h recovery, blood glucose and serum insulin levels were not different from control levels, indicating that the oral carbohydrate was mostly disposed in the body within 3 h. In addition, GLUT4 and HK II mRNA levels were significantly lowered in the exercised human skeletal muscle in subjects receiving the carbohydrate diet. In conclusion, the present study demonstrates that GLUT4 mRNA and HK II mRNA in the exercised human skeletal muscle were significantly lowered by a high-carbohydrate diet.

· Evolutionary Fitness

Comments

Posted by: Flower Online [TypeKey Profile Page] at September 11, 2006 2:15 PM


Sir.. you may know this fella, Steve Redgrave, x 4 Olympic rowing golds at consec. games.
Its rather pertinent vis insulin given what he used to eat.

I knew he was diagnozed as a diabetic some years back but given how they (him and Pinsent) trained and what Redgrave ate (see below) its little wonder his receptors are buggered.
His wifes a Doctor, BTW

http://www.telegraph.co.uk/wine/main.jhtml?xml=/wine/2005/05/07/edred07.xml

Posted by: SIMON FELLOWS at May 8, 2005 5:51 PM

Jorge's comment is very important in my opinion and it mirrors the result of the study I cited. The study looked at the glucose altered underlying gene expression that produced the result Jorge found with his blood glucose. The abdominal area will show the effect of a loss of insulin sensitivity pretty reliably. The reason has to do with the hierarchy of insulin sensitivity of tissues; muscle loses sensitivity, along with certain organs, whereas abdominal fat retains more sensitivity. Hence, you put fat there first.

By the way, a gram of CHO holds 9 grams of water, so you retain water weight at a high rate when you ingest this stuff.

Posted by: Arthur De Vany at May 8, 2005 5:45 AM

"I am slightly perplexed at the interest and comment on this topic; it must be that many have tried to read the magazines and research and have fallen for the party line on this topic."

An area in which Barnum & Bailey would have a field day with. There is so much research into this area, both for and against.I can't think of another topic which brings so much debate and controversy. I have experimented with both ways and have some results , albeit as Robb would say", just a sample size of one".
I used a post workout drink of 30 grams of whey, 15- 30 grams of dextrose and 10 grams of L-glutamine...it was used immediately after the workout. I also used the One Touch Ultra glucometer to measure glucose levels before the workout, 1 hour , and 2 hours after the PWO drink.
My average glucose prior to was 70-76, 1 hour after 120 -126 on several occassions!( Professor De Vany is close to having a cardiac at this point) and 2 hours after about 90-117. To say I was shocked is an understatement. I developed some abdominal fat that wasn't there before and LH were visible in only a 2 week period. I no doubt decreased my insulin sensitiviy during this period.
Thanks for the post Professor!

Posted by: Jorge Carvajal at May 7, 2005 6:21 PM

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