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-   -   British Medical Journal casts sceptical eye over sports drinks gospel (http://tt.tennis-warehouse.com/showthread.php?t=440453)

Thud and blunder 09-18-2012 02:04 AM

British Medical Journal casts sceptical eye over sports drinks gospel
 
http://www.bmj.com/content/345/bmj.e4737

Interesting read throughout.

ollinger 09-18-2012 04:53 AM

Nice summary of what the better medical literature (nephrology studies, vastly better quality than "sports medicine" studies) has shown for years -- that sports drinks are likely unnecessary garbage and that your body does an excellent job of making fluid and electrolyte shifts on its own as long as you drink enough water.

r2473 09-18-2012 07:06 AM

I like sugar during and after exercise. High fructose; low frucotse; "goldilocks fructose"; Doesn't really matter. Sports drinks work fine for me.

I've never really viewed them as a "water replacement" by any means. I think they compliment each other well.

There was no substantial evidence to suggest that liquid is any better than solid carbohydrate intake..............Through our analysis of the current sports performance research, we have come to one conclusion: people should develop their own strategies for carbohydrate intake largely by trial and error.

------------------------------------

With respect to hydration, thirst should be the main indicator that you need to hydrate. But since I moved to the high desert (Salt Lake), I do belive in the "bad science" of starting to hydrate before you start getting thirsty. Its different in this climate because of the low humidity.

Bartelby 09-18-2012 07:11 AM

'Disease mongering', indeed.

Chas Tennis 09-18-2012 07:12 AM

Thanks for posting the article.

Originally, there was the famous discovery that British seamen got scurvy because they were lacking fruits. Fruits were later learned to contain Vitamin C. The British navy supplemented fruits into their regular sea-going diet and scurvy was cured.

The supplement industry is escaliting marketing to an ever higher level. I believe, they mostly use the logic - if a chemical, vitamin, mineral, etc can be identified as important to a body process or body structure then supplementing those molecules, atoms, etc is likely to be beneficial. They write very reasonable sounding, detailed scientific model descriptions, down to the cell and molecule level. For example, read the many supplement ads in bodybuilding magazines.

Just because something seems perfectly reasonable does not make it true. But it does not make it untrue either. ? The only way to resolve the issue is with quality, neutral scientific research.

Neutral scientific research should be supported by a neutral government organization (NIH, etc.) or other neutral organization (neutral foundation). Some of it is. But the number of worthwhile research projects exceeds the small funding level available from government funds or other neutral organization. For a particular research project, unfortunately, 100% of the funding might be from self-interested sources with nothing from neutral sources. The government seems to have dropped the ball even on many of the most wide-reaching and serious medical research areas. (Are saturated fats or sugars most damaging for causing heart disease? ) So we get too much knowledge corruption from financially self-interested funded research.

The internet is seeing a lot of cut-and-paste descriptions so that popular unscientific or scientific conclusions appear widely verbatim on many websites. It is often more difficult to find scientific research among the many popular websites quoting the same few phrases. Search certain exact long medical or supplement phrases and you can find them on many websites. Does anyone have some advice on how to search more for neutral information as opposed to the most popular sites or those that influence search results in some financial or manipulative way?

On the other hand, if something seems perfectly true - but might not be true - what should you do? Reject it because most information is corrupted by funding from financially interested organizations?

For sports drinks, I read and it makes sense that the body uses up its glycogen stores in its muscles and liver and may run short during longer athletic activity. Also, I believe that the body sweats water and considerable sodium. I believe that some of the research on these issues is neutral. All things considered, I conclude that its reasonable for me to take in some calories and sodium during a tennis match. The possible value of the other ingredients in sports drinks is totally unknown to me.

A general reference that I use is Advanced Sports Nutrition, D. Bernardot. The reference seems neutral.

I am uncertain about all this. I'm not going to believe that all supplements are worthless or believe that they work as claimed. I can make a decision with considerable uncertainty - that's nearly all decisions.

With considerable doubt about the value, I supplement daily:

1) Glucosamine & chondroitin (2/3 recommended dose)
2) Vitamin C
3) Magnesium (Mg-Chloride not MgO)
4) Multi-Vitamin (5 days a week)
5) Fish Oil (for Omega 3)

Instead of just water I usually drink Powerade or Gatorade for calories and sodium during a tennis match.

charliefedererer 09-18-2012 07:29 AM

Parents don't have to send their kids off school with Gatorade in their backpacks to drink during gym class.

You don't need Gatorade to take the dog for a walk.

You don't need to send your kid off to a group tennis lesson with Gatorade.

You don't need Gatorade for social doubles ... heck any doubles.



But for 2 hour or longer hitting or playing sessions in the hot sun, I'll continue to take my Gatorade.

(I also think if I was a college coach in Florida runnning two-a-day practices in August, I'd have my team drinking Gatorade.)


I think there is just too much science to ignore, even if most of the studies are not large prospective randomized trials that the British Medical Journal is calling for. [Does anyone really think the NIH, or its equivalent in another nation, is going to sponsor a $100 million dollar study on sports drinks?]

"Most tennis athletes take the court, whether it is the first match or subsequent match of a tournament, in a dehydrated state. It has been shown that prior to thirst being recognized by an athlete, 1.5L of water could have already been lost 28. During an entire match, a player can lose fluid at a rate greater than 2.5L/hour 29 . Although these players consume fluids between sets, the maximum uptake of fluid is only 1.2L/hour30, 31. This creates a deficit in hydration status which can impede performance. It is known that a decrease of between 1.5-3% of body weight due to fluid loss results in decreased ability to generate maximum muscle strength, and decreases muscle endurance."
pp. 136 - 137" http://assets.usta.com/assets/1/dps/...CT%20FINAL.pdf


'Below et al., studied athletes who consumed different volumes of an electrolyte drink or an electrolyte-carbohydrate drink. Participants consumed drinks containing either electrolytes (619 mg Na+, 141 mg K+) or the same electrolytes plus carbohydrates (79g carbohydrates) during an initial 50 minute exercise bout, and then immediately undertook a cycle ergometer performance test. They received these drinks in either a large (1330 ml) or small (200 ml) volume. Fluid and carbohydrate each improved performance independently: performance times were 6.5% faster when the large beverage volume was consumed as opposed to the small volume, and were 6.3% faster when carbohydrate-containing beverages were consumed as opposed to the carbohydrate-free beverages64
. Both fluid consumption and carbohydrate replenishment are important factors that delay fatigue during high exercise performance 5.
Sodium also stimulates glucose absorption in the small intestine via the active co-transport of glucose and sodium, which creates an osmotic gradient that acts to promote net water absorption. Sodium has been recognized as a vital component of a rehydration beverage by an inter-association task force 65 on exertional heat illnesses because sodium plays a role in the aetiology of exertional heat cramps, exertional heat exhaustion and exertional hyponatremia. Shirreffs and Maughan 66 have reported that for athletes to remain in positive fluid balance, the amount of sodium they consume needs to be greater than sweat sodium loss. Yet research has been shown that athletes typically do not replace sufficient sodium to match that which is lost in sweat and during urinary sodium excretion. Subjects were shown to be in sodium deficit for four hours after exercise, even when replacing with a commonly used carbohydrate-electrolyte beverage at 150% of body-mass lost during exercise 57. The recovery of plasma volume to levels greater than post-exercise was achieved 1 h after rehydration in the 6% carbohydrate-electrolyte drink whereas the water trial achieved the same level after 3h 57. A similar finding has been supported by other research 59. This body of research has shown that rehydration capabilities are improved for athletes who ingest sodium enriched fluids compared to plain water. "
pp. 183-184 http://assets.usta.com/assets/1/dps/...CT%20FINAL.pdf

"Initial signs of exertional heat cramps (muscle twitches) can often be treated effectively by consuming 16-20 ounces (~0.5 L) of a traditional sport drink with 0.5 teaspoon (3g) of salt added and mixed into the drink75. Salt tablets may be a suitable option (1g of NaCl per tablet) but such tablets should be taken with plenty of fluid (3 crushed and dissolved tablets in 42 ounces (~1L) of fluid).It is vital that cramp-prone athletes avoid a water and sodium deficit from previous training or tournament play so that they do not begin the next training or competition bout already at risk82, 83. Figure 3 provides strategies for exertional heat cramp-prone athletes."
- p. 190 http://assets.usta.com/assets/1/dps/...CT%20FINAL.pdf

"An original aspect of this study was the comparison of plasma glucose, liver glucose, and muscle glycogen oxidation (including the lactate shuttle) rates during exercise, after galactose and glucose ingestion. These data indicate that plasma glucose oxidation rates after Glu ingestion are greater during the initial hour of exercise in comparison with Gal."
- http://journals.lww.com/acsm-msse/Fu...ion_on.17.aspx

ollinger 09-18-2012 07:48 AM

^^ the NIH in fact HAS funded quite a few studies of sports drinks, with varying outcomes.

charliefedererer 09-18-2012 08:24 AM

^^^ Such as?

Bowtiesarecool 09-18-2012 09:08 AM

Interesting fact: The original gatorade developed for UoF worked well at aiding the body in retaining water and giving a short energy boost. However, the formula changed since marketing and is now nothing like the original.

Interesting fact #2: The color of urine is an indicator of where your body is currently getting it's nutrients from. more clear = from food you recently ate, more yellow = you're burning stored body fat. This has been known since the early days of animal experimentation.

sureshs 09-18-2012 11:36 AM

Quote:

Originally Posted by charliefedererer (Post 6906218)
Parents don't have to send their kids off school with Gatorade in their backpacks to drink during gym class.

hehe have been doing that with my son for years. It was supposed to be for PE class, but it continues even today even though he is done with PE.

charliefedererer 09-18-2012 07:07 PM

Quote:

Originally Posted by Bowtiesarecool (Post 6906425)
Interesting fact: The original gatorade developed for UoF worked well at aiding the body in retaining water and giving a short energy boost. However, the formula changed since marketing and is now nothing like the original.

While the formula changed, isn't it actually still a lot like the original, and was brought to market by the original inventor of the formula?

"Invention of Gatorade

In 1965, Cade was approached by Dewayne Douglas, an assistant coach for the Florida Gators football team, about the extreme dehydration faced by Gator football players practicing in the high temperatures and humidity of the Deep South in late summer and early fall.[11] Douglas questioned Cade why his football players did not urinate during practice and games.[11] Cade learned from anecdotal evidence that football players were losing water through perspiration and failing to replace fluid during practice and games.[11] Cade's research team discovered that football players were losing up to 18 pounds (8.2 kg) during the three hours of a college football game, and that ninety to ninety-five percent of that loss was water.[6] A player's plasma volume could decrease as much as seven percent and blood volume by five percent, and sodium and chloride were excreted in the sweat.[6]
During 1965 and 1966, Cade, together with his team of research doctors Dana Shires, James Free, and Alejandro M. de Quesada, conducted a series of trial-and-error experiments with his glucose-and-electrolytes rehydration drink on members of the Gators football team of coach Ray Graves, first with members of the freshman squad, and after initially promising results, with starting members of the varsity team.[1] "It didn't taste like Gatorade," Cade said in a 1988 interview with Florida Trend magazine.[2] In fact, according to Cade, when Gators lineman Larry Gagner first tried it, he spat it out and strongly suggested that the original experimental formula tasted more like bodily waste.[2][12] Dana Shires remembered that "it sort of tasted like toilet bowl cleaner."[13] To make it more palatable, at the suggestion of Cade's wife, the researchers added lemon juice and cyclamate[14] to the original formula of water, salt, sodium citrate, fructose and monopotassium phosphate.[13]
Cade patented the formula and offered all of the rights to the drink to the University of Florida in exchange for the university's backing of the production and marketing of the drink, but the university turned down his proposal.[19] He initially obtained bank financing and began to produce "Gatorade" through his own business, but later entered into a contract with Stokely-Van Camp, Inc. to produce and sell the drink.[14] When sales royalties reached $200,000, the university took notice.[20] The Florida Board of Regents, prompted by the U.S. Department of Health, Education and Welfare, which had provided Cade with a small grant for his research, asked for the patent rights.[21] Cade refused.[20] The Board of Regents, acting on behalf of the university, then brought suit against Cade for a share of the profits,[21] arguing that the university's facilities, employees and students were instrumental in the development of the product.[20][22] After thirty-one months of legal wrangling, Cade and the university negotiated a settlement of their dispute in 1972,[20] and the Board of Regents and the university settled for a twenty percent share of the royalties.[22] Cade, and his investors in the Gatorade Trust, retained eighty percent. In the aftermath of the settlement, all parties decided to play nice—of the first $70,500 in Gatorade royalties received by the university, the university reinvested $30,000 in kidney research by Cade's renal department and another $12,000 in Cade's other research projects.[23]"
- http://en.wikipedia.org/wiki/Robert_Cade



Quote:

Interesting fact #2: The color of urine is an indicator of where your body is currently getting it's nutrients from. more clear = from food you recently ate, more yellow = you're burning stored body fat. This has been known since the early days of animal experimentation.

Isn't by far the major determinant of the color of urine how concentrated it is? That is, in a well hydrated individual the color is almost clear, while in someone dehydrated it appears as a dark yellow?
Indeed, how clear/dark the urine appears can be used by tennis players to determine if they remain dehydrated after a long hot practice in the sun: http://assets.usta.com/assets/1/15/Am_I_Hydrated_2.pdf


Bartelby 09-18-2012 07:19 PM

I think I'll start urinating beside the court at the change of sets from now on.

Bowtiesarecool 09-18-2012 07:51 PM

Quote:

Originally Posted by charliefedererer (Post 6907345)
While the formula changed, isn't it actually still a lot like the original, and was brought to market by the original inventor of the formula?

It's not the same as it used to be. Nowadays it's pretty much just sugarwater.


[/quote] Isn't by far the major determinant of the color of urine how concentrated it is? [/quote]

Possibly. The article argues this point. I did mistakenly state that urine color was a determinate factor in how the body is processing nutrients. Whether or not the body is feeding off of fat can be determined by inspecting the cloudiness/acidity of the urine. Something dicovered by Claude Bernard in the late 1860's. Obviously that has nothing to do with the article in question, though it's an interesting topic on it's own. Forgive me oh great Sampras' ghost, for I have made an incorrect statement on the interwebs.

LuckyR 09-19-2012 07:37 AM

The article cited by the OP, is a nice review of the unwarranted claims of the Sports Drink industry. However, anyone with a rudimentary understanding of the physiology involved and of capitalistic business practices would have predicted them.

Bottom line, nothing hydrates "better" than water. Sports drinks hydrate "faster" than water, but for the majority of people exercising, there is no measurable benefit to this difference.

sureshs 09-19-2012 08:03 AM

Quote:

Originally Posted by charliefedererer (Post 6907345)
While the formula changed, isn't it actually still a lot like the original, and was brought to market by the original inventor of the formula?

"Invention of Gatorade

In 1965, Cade was approached by Dewayne Douglas, an assistant coach for the Florida Gators football team, about the extreme dehydration faced by Gator football players practicing in the high temperatures and humidity of the Deep South in late summer and early fall.[11] Douglas questioned Cade why his football players did not urinate during practice and games.[11] Cade learned from anecdotal evidence that football players were losing water through perspiration and failing to replace fluid during practice and games.[11] Cade's research team discovered that football players were losing up to 18 pounds (8.2 kg) during the three hours of a college football game, and that ninety to ninety-five percent of that loss was water.[6] A player's plasma volume could decrease as much as seven percent and blood volume by five percent, and sodium and chloride were excreted in the sweat.[6]
During 1965 and 1966, Cade, together with his team of research doctors Dana Shires, James Free, and Alejandro M. de Quesada, conducted a series of trial-and-error experiments with his glucose-and-electrolytes rehydration drink on members of the Gators football team of coach Ray Graves, first with members of the freshman squad, and after initially promising results, with starting members of the varsity team.[1] "It didn't taste like Gatorade," Cade said in a 1988 interview with Florida Trend magazine.[2] In fact, according to Cade, when Gators lineman Larry Gagner first tried it, he spat it out and strongly suggested that the original experimental formula tasted more like bodily waste.[2][12] Dana Shires remembered that "it sort of tasted like toilet bowl cleaner."[13] To make it more palatable, at the suggestion of Cade's wife, the researchers added lemon juice and cyclamate[14] to the original formula of water, salt, sodium citrate, fructose and monopotassium phosphate.[13]
Cade patented the formula and offered all of the rights to the drink to the University of Florida in exchange for the university's backing of the production and marketing of the drink, but the university turned down his proposal.[19] He initially obtained bank financing and began to produce "Gatorade" through his own business, but later entered into a contract with Stokely-Van Camp, Inc. to produce and sell the drink.[14] When sales royalties reached $200,000, the university took notice.[20] The Florida Board of Regents, prompted by the U.S. Department of Health, Education and Welfare, which had provided Cade with a small grant for his research, asked for the patent rights.[21] Cade refused.[20] The Board of Regents, acting on behalf of the university, then brought suit against Cade for a share of the profits,[21] arguing that the university's facilities, employees and students were instrumental in the development of the product.[20][22] After thirty-one months of legal wrangling, Cade and the university negotiated a settlement of their dispute in 1972,[20] and the Board of Regents and the university settled for a twenty percent share of the royalties.[22] Cade, and his investors in the Gatorade Trust, retained eighty percent. In the aftermath of the settlement, all parties decided to play nice—of the first $70,500 in Gatorade royalties received by the university, the university reinvested $30,000 in kidney research by Cade's renal department and another $12,000 in Cade's other research projects.[23]"
- http://en.wikipedia.org/wiki/Robert_Cade






Isn't by far the major determinant of the color of urine how concentrated it is? That is, in a well hydrated individual the color is almost clear, while in someone dehydrated it appears as a dark yellow?
Indeed, how clear/dark the urine appears can be used by tennis players to determine if they remain dehydrated after a long hot practice in the sun: http://assets.usta.com/assets/1/15/Am_I_Hydrated_2.pdf


The problem is that taking multivitamins also seems to make the urine color yellower, not just dehydration.

Thud and blunder 09-19-2012 08:06 AM

I notice that Dr Noakes, who features prominently in that BMJ piece, has written a book containing probably more than anyone cares to know about sports hydration:



Not sure if I'm up for 400+ pages on the topic, though.

El Diablo 09-19-2012 08:06 AM

I'm far less concerned about the color of my urine than about the things they use to color beverages like Gatorade. Brominated vegetable oils, used to make the drink more opaque, are banned in Europe and parts of Asia and were the subject of a good review of their health hazards last year in Scientific American. I'll take water, thanks.

r2473 09-19-2012 09:01 AM

Just returned from the restroom. My urine this morning appeared to be Jasmine in color.

http://www.youtube.com/watch?v=its0qifGDxU

I'll post an update later today with pics.

mikeler 09-19-2012 09:23 AM

I need something to prevent cramping in the Florida heat. I'm a fan of Gatorade. Was I supposed to read the study to comment in here?

El Diablo 09-19-2012 10:26 AM

^^ if you're unable to figure out how these threads work, you might be dehydrated.


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