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-   -   Need Studies/journal Articles! (http://www.catalystathletics.com/forum/showthread.php?t=4061)

Evan Levy 03-23-2009 03:03 PM

Need Studies/journal Articles!
 
I am currently working at a facility that is all about high carb/high glycemic load diets to improve performance and health. I have been trying to find specific studies/journal articles that prove a low insulin and proper balance of macronutrient meal plan can improve performance and reduce the risk of disease. I have been zoning for 5 months and have seen benefits first hand, however, I want more studies to prove that there is an alternate route to a high carb/insulin diet. Any and all information would be helpful.

Mike ODonnell 03-23-2009 05:27 PM

Is this a "sports performance" place by any chance?

Darryl Shaw 03-24-2009 08:19 AM

Quote:

The zone diet and athletic performance.

Cheuvront SN.

Department of Nutrition, Food, and Exercise Sciences, Florida State University, Tallahassee, USA.

The Zone diet is the latest eating regimen marketed to improve athletic performance by opposing traditional high carbohydrate sports diets. The 40/30/30 diet is centred primarily on protein intake (1.8 to 2.2 g/kg fat free mass; i.e. total bodyweight-fat weight) and promises a change in the body's insulin to glucagon ratio through its macronutrient alterations. Changes in the existing hormonal milieu are said to result in the production of more vasoactive eicosanoids, thus allowing greater oxygen delivery to exercising muscle. This favourable condition, known as the Zone, is anecdotally reported to benefit even the most elite endurance athletes. Applying the Zone's suggested protein needs and macronutrient distributions in practice, it is clear that it is a low carbohydrate diet by both relative and absolute standards, as well as calorie deficient by any standard. Reliable and abundant peer reviewed literature is in opposition to the suggestion that such a diet can support competitive athletic endeavours, much less improve them. The notion that a 40/30/30 diet can alter the pancreatic hormone response in favour of glucagon is also unfounded. The Zone is a mixed diet and not likely to affect pancreatic hormone release in the same way individual nutrients can. Although the postprandial insulin response is reduced when comparing a 40% with a 60% carbohydrate diet, it is still a sufficient stimulus to offset the lipolytic effects of glucagon. Many of the promised benefits of the Zone are based on selective information regarding hormonal influences on eicosanoid biology. Contradictory information is conveniently left out. The principle of vasodilating muscle arterioles by altering eicosanoid production is notably correct in theory. However, what little human evidence is available does not support any significant contribution of eicosanoids to active muscle vasodilation. In fact, the key eicosanoid reportedly produced in the Zone and responsible for improved muscle oxygenation is not found in skeletal muscle. Based on the best available scientific evidence, the Zone diet should be considered more ergolytic than ergogenic to performance.
http://www.ncbi.nlm.nih.gov/pubmed/1...ubmed_RVDocSum

You can also find a review of the Zone Diet in Clinical Sports Nutrition (3rd edition) by Louise Burke and Vicki Deakin (p.146-8, 475-6) but they reach the same conclusion as above ie. the Zone Diet is to low in calories and carbohydrates to be of any use to athletes and will in all probability have a detrimental effect on performance.

Mike ODonnell 03-24-2009 08:31 AM

I'm not a fan of the Zone...but I know you can adjust blocks or whatever they call them to get higher intake of calories. A zone at a standard level is VERY low in calories....but you can make the calories high and keep the ratios. But...I don't do zone and like my carbs pwo. ANY diet too low in calories is not ideal for athletic performance....even high carbohydrate low calorie.

I'd be more interested in a study comparing diet protocols of the SAME amount of calories and different ratios of macroutrient intake rather than you using every thread as an opportunity to dismiss everything but a high carb diet as ideal.

Liam Dougherty Springer 03-24-2009 12:46 PM

MOD- I know Evan personally and what he needs more than anything is articles/study reviews that are peer reviewed which show benefits of diets conducive to the use of stored energy during exertion. Basically something to combat the idea that food fuels the function and more that food refuels depletion.

I along with many came into my current dietary plan of “eat what my body asks for when it asks for it” through a Paleo/Zone/IF approach and then playing around from there. But today I realize while the zone is a way to open my metabolism to a more proper hormonal balance, eventually that just lead me to more appropriately listening to my body.

So I don't think this thread is best put in the Zone section however I understand why it has ended up here. Coach Glassman and crossfit in general adopting the Zone as a Rxed performance diet has put it on the front page so to speak. Now that Robb Wolff has so cunningly described a more appropriate and malleable dietary design and labeled it the athletes Zone we have a bunch of CFers claiming they zone while in fact they are just eating a well put together performance diet based on the idea of refueling and increasing nutrient delivery and utilization through natural metabolic function within the human, as a species.

So what I was hoping to find myself in this thread was some information involving the aid of insulin sensitivity through a reduced intake of highly digestible carbohydrate sources throughout the day and utilizing the glycogen preferred storage window for refueling as well as a fat adapted metabolism through increased caloric intake of healthy fats. Leading to a conclusion that functioning on stored fuel is more efficient than eating a power bar before getting to the gym and constantly sucking down HFCS water while working out.

I will also hopefully be turning the RD at my place of employment onto these references so the clients I refer to the lovely woman (and I really mean that she is awesome) will be in the hands of someone who is at least informed as to why I hold these opinions and thus state the requests of her that I do.

Thanx for the time and attention of any who give it,
Liam

Liam Dougherty Springer 03-24-2009 12:52 PM

Oh yeah lets not beat the fact that the Zone as Dr. Sears has outlined is so low calorie as to make recovery and performance far from ideal for a few, and just dangrouse and impossible for the rest. That horse is at the foot of someones bed by now.:p

Donald Lee 03-24-2009 01:42 PM

Quote:

Originally Posted by Liam Dougherty Springer (Post 53576)
MOD- I know Evan personally and what he needs more than anything is articles/study reviews that are peer reviewed which show benefits of diets conducive to the use of stored energy during exertion. Basically something to combat the idea that food fuels the function and more that food refuels depletion.

I along with many came into my current dietary plan of “eat what my body asks for when it asks for it” through a Paleo/Zone/IF approach and then playing around from there. But today I realize while the zone is a way to open my metabolism to a more proper hormonal balance, eventually that just lead me to more appropriately listening to my body.

So I don't think this thread is best put in the Zone section however I understand why it has ended up here. Coach Glassman and crossfit in general adopting the Zone as a Rxed performance diet has put it on the front page so to speak. Now that Robb Wolff has so cunningly described a more appropriate and malleable dietary design and labeled it the athletes Zone we have a bunch of CFers claiming they zone while in fact they are just eating a well put together performance diet based on the idea of refueling and increasing nutrient delivery and utilization through natural metabolic function within the human, as a species.

So what I was hoping to find myself in this thread was some information involving the aid of insulin sensitivity through a reduced intake of highly digestible carbohydrate sources throughout the day and utilizing the glycogen preferred storage window for refueling as well as a fat adapted metabolism through increased caloric intake of healthy fats. Leading to a conclusion that functioning on stored fuel is more efficient than eating a power bar before getting to the gym and constantly sucking down HFCS water while working out.

I will also hopefully be turning the RD at my place of employment onto these references so the clients I refer to the lovely woman (and I really mean that she is awesome) will be in the hands of someone who is at least informed as to why I hold these opinions and thus state the requests of her that I do.

Thanx for the time and attention of any who give it,
Liam

Liam,

IMO, a lot of what you've stated is false. There's a happy medium between the extremes of Zoners/CrossFitters and the common bodybuilding-influenced nutrition knowledge.

For example, why would running on stored fuel be more efficient than eating a powerbar before working out? If in your workout, you end up depleting your glycogen, you would probably wish you had that powerbar pre-workout.

Just as training prescriptions are all relative to the goals, nutrition is also relative to people's goals.

And nutrition for general health is different from nutrition for sports performance.

Liam Dougherty Springer 03-24-2009 02:22 PM

Quote:

Originally Posted by Donald Lee (Post 53592)
Liam,

IMO, a lot of what you've stated is false. There's a happy medium between the extremes of Zoners/CrossFitters and the common bodybuilding-influenced nutrition knowledge.

For example, why would running on stored fuel be more efficient than eating a powerbar before working out? If in your workout, you end up depleting your glycogen, you would probably wish you had that powerbar pre-workout.

Just as training prescriptions are all relative to the goals, nutrition is also relative to people's goals.

And nutrition for general health is different from nutrition for sports performance.


I almost made my already long post even longer by stating information dealing with what you just posted. I was honestly just hoping to find support for my opinions not begin a debate on apples and oranges and which is the better fruit. That being said I don't see were your post and mine are in any seriouse conflict.

If you are talking about endurance events in which you are required to have a long steady exertion of energy requiring a caloric output which far surpasses your glycogen storage then yes you are right you had better be fueling up as constantly with as easily digestible sources of energy as possible while exerting the energy. Outside of those events I stick to my opinions and I don't see where you are disagreeing. Even in those cases for health AND performance as stated in the original post and general metabolic function sticking to vegetables and some fruit as your primary source of carbohydrates and relying on them to restore glycogen rather than keep blood glucose available for energy would IMO be preferable. For this reason even the endurance athlete would do well to understand the legitimacy of the principles I stated above. So while we are both right it would still be nice to be able to present some information on the subject at hand being a healthy performance bias diet from my side as the majority of "general Knowledge" in the industry currently comes from the other.

I recognize that my comment as to the power bar was condescending and I do apologize if it offended anyone. I ate a cliff bar PWO just the other day, if it helps you feel better, I am not above a nutrient dense carb indulgence though I prefer pizza and ice cream.:D

Donald Lee 03-24-2009 02:57 PM

This study might be useful, but it's for endurance athletes:

http://www.jacn.org/cgi/content/full/19/3/345

Quote:

It has been shown that high CHO (60% to 70%) and low-fat (10% to 15%) diets enhance endurance performance, and high-fat diets (60%) are detrimental to performance. Athletes eating high-carbohydrate (low-fat) diets do not consume as many calories as they expend and may not meet the ADA levels of iron and zinc. Recent data, also, indicate that diets comprising 32% to 55% fat can improve endurance capacity compared to diets with 15% fat. There is evidence that fit subjects have higher fat oxidation due to increased enzyme levels, fatty acid transport and beta oxidation. In addition, intramuscular triglycerides and intracellular fats can be increased by a high-fat diet and can support higher levels of fat oxidation without compromising CHO stores. It is clear that if CHO intake is reduced to below 20% of total calories, or to less than 1.9 g/kg/day, glycogen stores are compromised and therefore performance will be compromised. Similarly, reducing fat intake to less than 20% of total calories compromises fat stores and therefore endurance performance.

It appears that a critical issue regarding the role of diet in exercise is that total caloric intake must be balanced to total caloric expenditure. Furthermore, the substrates consumed should replenish the intramuscular stores of the substrates used during training and competition. In trained athletes eating isocaloric diets that have sufficient levels of fats and CHOs (muscle stores), our data suggest that the blend of fats and CHOs used during exercise is set by the intensity of the exercise and is constant throughout the exercise time. Most scientists agree that a diet containing 15% to 20% protein calories is sufficient to meet the protein demands of most athletes. Thus a general isocaloric diet should comprise 30% to 35% CHOs, 30% fats and 20% protein, with the balance (20%) of total calories supplying the substrates used in training and competition. For competitions requiring exercise intensities of up to 85% of Vo2max, dietary fats may be more beneficial. For exercise intensities above 100% of Vo2max, CHOs would be the preferred macronutrient. The ratio of the intake of fats and carbohydrates to optimize performance for exercise between 80% to 100% Vo2max remains to be investigated.

Mike ODonnell 03-24-2009 05:00 PM

depends on the sport....like all things above....what is the effort level, how long are the periods of exertion, etc. A pole vaulter and NFL running back would not be the same. For professional sports involving explosion over 30sec and < 2-3 min (glycolitic), they need glycogen....which needs to be already in the muscles. Now extend that over 2-3 hours like a hockey game and you bet your ass they will probably need some gatorade....but that's just during the game.


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