Discussion in 'Health & Fitness' started by Thud and blunder, Sep 18, 2012.
Interesting read throughout.
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.
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.
'Disease mongering', indeed.
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.
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/usta_master/sitecore_usta/RECOVERY PROJECT FINAL.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/usta_master/sitecore_usta/RECOVERY PROJECT FINAL.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/usta_master/sitecore_usta/RECOVERY PROJECT FINAL.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."
^^ the NIH in fact HAS funded quite a few studies of sports drinks, with varying outcomes.
^^^ Such as?
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.
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.
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. Douglas questioned Cade why his football players did not urinate during practice and games. Cade learned from anecdotal evidence that football players were losing water through perspiration and failing to replace fluid during practice and games. 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. 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.
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. "It didn't taste like Gatorade," Cade said in a 1988 interview with Florida Trend magazine. 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. Dana Shires remembered that "it sort of tasted like toilet bowl cleaner." To make it more palatable, at the suggestion of Cade's wife, the researchers added lemon juice and cyclamate to the original formula of water, salt, sodium citrate, fructose and monopotassium phosphate.
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. 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. When sales royalties reached $200,000, the university took notice. 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. Cade refused. The Board of Regents, acting on behalf of the university, then brought suit against Cade for a share of the profits, arguing that the university's facilities, employees and students were instrumental in the development of the product. After thirty-one months of legal wrangling, Cade and the university negotiated a settlement of their dispute in 1972, and the Board of Regents and the university settled for a twenty percent share of the royalties. 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."
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
I think I'll start urinating beside the court at the change of sets from now on.
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.
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.
The problem is that taking multivitamins also seems to make the urine color yellower, not just dehydration.
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.
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.
Just returned from the restroom. My urine this morning appeared to be Jasmine in color.
I'll post an update later today with pics.
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?
^^ if you're unable to figure out how these threads work, you might be dehydrated.
I take a 16oz Gatorade with me to any match. I do one sip every changeover and drink water after that. I rarely get into a battle that 16oz isn't enough sugar and electrolyte to sustain my hydration and energy.
I tried coconut water and felt it did well too. Just can't justify the high price tag when Publix sells 8-packs of Gatorade for 5 bucks and are often buy one-get one free. Coconut water is around 4 bucks for 20oz.
There is an inverse relationship between the reliability of a medical journal article and the financial conflict of interest of the persons involved in the writing and any underlying studies. Scientific fraud in America is epidemic. I know of no basis to distinguish the British in that regard.
Well said. Just be aware that the drug industry has a lot more money to spend than its competition to prove that the competition's products are not effective.
Squatters rights, I suppose .....
These Brits win one damn slam in something like 100 years and they are all the sudden experts on everything.
I suppose next we'll be taking advice from the Cubs.
I always thought that if it's clear you're hydrated, but if it's more dark then you're dehydrated.
When I attended U. of F. ( 1975-1978 ) it seemed typical that the football team would start strong early in the season with people naming them as contenders to win in their conference, only to fall back to mediocrity as the season progressed. I speculated that they began the season with a huge advantage over their opponents in heat adaptation, which became decreasingly relevant as the autumn progressed.
In 1978 I attended a dinner sponsored by Tau Beta Pi (an engineering society) at which Dr. Cade was the featured speaker. In his words, the player told him that his drink "tastes like ****!" Dr. Cade continued, "Having never tasted ****, myself, I could not vouch for his claim. Nevertheless, we did work to improve its flavor."
As to the original issue, I recommend drinking water and snacking on any food high in potassium.
Orange juice is high in potassium. But, I think it's a good idea to keep your electrolites in balance. I don't think it's helpful to supplement with only one.
By far, the most important electrolyte to replace during long tennis sessions in the hot sun is sodium - not potassium.
"Sodium’s Role in Hydration and Rehydration for Tennis
The importance of the addition of sodium to fluid consumed during, and especially
after training or competition has been shown to be vital for improved rehydration.
The need for sodium replacement is due in part from sodium’s role as the major ion
in the extracellular fluid, and to replace the obligatory losses in sweat."
- http://assets.usta.com/assets/1/dps/usta_master/sitecore_usta/RECOVERY PROJECT FINAL.pdf
"Many athletes do not consume enough sodium in their regular diet to support strenuous physical activity, especially in early stages of training and in hot and/or humid environments.
Having recovery drinks and food that contain sufficient levels of sodium is helpful for a number of purposes:
- Replaces the sodium that is lost in sweat
- Stimulates glucose (energy) absorption by
- Increases the athletes drive to drink
- May reduce the symptoms of exertional heat cramps, exertional heat exhaustions and exertional hyponatremia
During multi-day tournaments or practice, it is common for players to experience a subtle but gradual sodium deficit and this can result in heat and hydration related problems (exhaustion, cramping etc) towards the later
rounds of tournament."
- http://assets.usta.com/assets/1/dps...ence/RECOVERY PROJECT 22410 EMAIL VERSION.pdf
"As sodium has important other benefits such as increasing drive to drink Heat and Hydration Recovery in Tennis USTA Recovery Project 187 and replacing sodium losses that are large in sweat, it appears from the literature that no added benefit is gained by adding potassium to recovery drinks. Potassium rich foods or supplements have not typically been shown to provide additional benefit 75. "
- http://assets.usta.com/assets/1/dps/usta_master/sitecore_usta/RECOVERY PROJECT FINAL.pdf
Muscle cramping during and after tennis play is an unwarranted aspect of
high-level competitive tennis. Cramps typically occur with slight muscle
fasciculations 75 or “twitches” that the athlete only notices between points or at the changeover. These subtle signals alert the athlete (and coach) that s/he may only have 20-30 minutes before severe cramps may occur, which would severely hinder the athletes ability to perform at a competitive level. These cramps are often experienced post-play during recovery, between matches and between days during training and competition. With respect to exercise-related muscle cramping, there are typically two forms of cramping that tennis players are most often confronted with:
1) Overworked muscle fibers
2) Muscle cramps related to extensive sweat losses and a sodium deficit,
known as exertional heat cramps 75."
- http://assets.usta.com/assets/1/dps/usta_master/sitecore_usta/RECOVERY PROJECT FINAL.pdf
I thought muscle cramps were caused by lack of Potassium. Isn't this the reason for players eating bananas?
I can't drink anything acidic during matches anymore or I have to sprint to the rest room with explosive diarhea.
That rules out pretty much every sports drink as they all have citric acid.
True Sports drinks contain sodium and severe sodium loss is a cause of muscle cramping and replacing it at that point can relieve the cramping. However from a practical standpoint there are other information to put the above into context:
Muscle cramping is rare in tennis matchplay, regardless of drinks, supplements, weather conditions etc
Only the most severe circumstances lead to cramps, Chang in the French etc.
The main benefit, therefore, of the sodium in sprts drinks is for more rapid rehydration, than warding off cramps.
In the rare case of actual muscle cramps or a legitimate case where the risk of cramps would be high, the levels of sodium in sports drinks is way too low. That's what pickle juice (or salt tabs) is for.
Old myths die hard.
It used to be thought that low potassium was the major reason for cramping - hence the emphasis on eating bananas that are rich in potassium.
But that is no longer believed.
[Still eating a banana after a match or practice is not a bad idea. It is fairly easy to digest and contains enough carbohydrates to start replacing muscle glycogen (muscle's immediate energy supply) lost during play.
During a match, some can tolerate eating a banana - others develop intestinal cramping.]
I agree with all of the above.
Prevention of muscle cramping is not the primary reason for staying hydrated with sodium containing sport drinks.
Probably the only ones at real risk for low sodium related cramps are those practicing playing day after day in the hot summer, and who have a low sodium diet. (Most Americans probably take in an excess of sodium overall in their diets.) Still, I could see my daughters, who have very low sodium diets, getting into trouble at a tennis camp if they drank only water day after day.
Exactly. When you drink pickle juice or take salt tablets, you're destroying a key health benefit of exercise, namely counteracting your high-blood-pressure-causing excess sodium intake.
By the way, it might make sense for a _British_ medical journal to discourage use drinks to compensate for heavy sweating. Who sweats heavily in their climate?
In the last few weeks I've given up the whole sports drink / high energy drink /caffeine thing. Used to guzzle 3-4 energy drinks before/during a match, some with caffeine eg. Gator, Relentless, Monster, would have a double expresso with a couple of sugars 30 mins before the match to perk me up etc.
It just all played yo-yo with my moods and energy levels. Would end up psyched, aggressive, super tense with too much energy in the first match and then super flat in any match going towards the 2-3 hour point. I just don't believe that any of that stuff or too many stimulants is good for you (well, it wasn't good for me). At times, I was doing a good impression of someone on PEDs.
Now I just try and prepare normally. Have a good nights sleep, healthy meal, a mixed orange cordial during the match and occasionally, a electrolyte drink as I seem to suspectible to muscle cramps in the 2nd match of tourneys for some reason. Could probably achieve the same effect with table salt and water.
You could try using that to psych out your opponents.
True, but as I stated in my post, using pickle juice or salt tabs would be a once in a career advantage for players not on the tour, unless you live in the desert and like to play long matches midday. I grew up in SoCal in the Golden Age of American tennis and played midday all the time and have never had muscle cramps from tennis.
Generally water is sufficient. Sometimes the sugar helps. Frankly, I think the flavor is an incentive to drink more so that people do end up more hydrated because they drink more
As I have tried to cut out a lot of artificial stuff lately, I drink only water these days
I've looked at lucozade sport, gatorade and powerade. They all contain 200mg of salt. Can I replace these with a food that has 200mg of salt, and eat something sugary? I can't stand the taste of sports drinks. A banana barely has any salt, so it doesn't seem that useful. Although Rafa eats bananas in matches??
You lose B vitamins and minerals through sweating. Is it not a good idea to replace them? I used to take a multivitamin to combat this.
^^ there is no significant loss of B vitmins in sweat. Perhaps you're confusing studies that suggest B vitamins may reduce sweating.
That was my source. I know Livestrong is not always reliable.
"As water or sweat is emitted from the body, excess water-soluble vitamins are lost."
"Frequent consumption of vitamins B and C is necessary to replenish nutrients lost due to perspiration and urination."
^^ "not always reliable" barely is sufficient. Did you notice that the article you cite has "sponsored links" recommendations woven into the text?
Well it is a lance armstrong company, so it figures that there will be a few lies in there.
I've looked at lucozade sport, gatorade and powerade. They all contain 200mg of salt. Can I replace these with a food that has 200mg of salt, and eat something sugary? I can't stand the taste of sports drinks. A banana barely has any salt, so it doesn't seem very useful. Although Rafa eats bananas in matches??
He also consumes sports drinks
without sports drink in the 3rd set or earlier you'll be as flat as carbonated drink left open for days.
Yes, you can get your salt intake from anything containing salt.
Here is a chart that displays the sodium content of various foods:
(I am not advocating the foods above, I just wanted to include a chart to show that you can google the sodium content of any food to find out how much sodium is in it.)
Alternatively, you can add sodium chloride (table salt) to any food or beverage you choose.
(In the chart above, you can see that one teaspoon of salt has 2,325 gm of sodium.)
Good for you that you don't like sugary drinks.
[But you may want to check out post #11 to see how Gatorade - the grand daddy, of sports drinks, came to be made. In short, the research team that the Florida Gators football team asked to help keep their football team hydrated, had to add in sugar, sweeteners and lemon to make the drink palatable enough to get the players to actually drink it.]
I am not saying this about you, but the problem for most Americans is that they consume too much sodium, not too little.
What's sneaky is how much sodium there is prepared foods that you may not have thought about.
For instance, a quart jar of standard Prego tomoto sauce has about 4,000 gm of sodium - or you can buy totally sodium free sauces or make your own from canned pureed tomatoes.
McDonald's certainly know this:
Somebody in another thread suggested substituting bacon for sports drinks.
Can I just eat any old sugary candy? Sports drinks claim to have special carbohydrate formula's that maximize energy and stamina levels. This could save me a lot of money, as sports drink's are pricey in the UK.
The prices are ridiculous for what you're getting.
But they convinced people to buy water too so...........
i drink water before during and after my matches/practice sessions. not in OSD way, just not to be thirsty/dehydrated. you lose focus. no need to drink dyed water at €6 a bottle...
post match i eat what the pros eat. cheeseburgers, pasta dishes, pizza or whatever is for dinner when out with all the money i've saved not buying dyed water from miscellaneous-ade.
i have enough body fat and eat well enough during the day to have energy for playing tennis, sprinting, swimming or any other activity i'm doing.
Separate names with a comma.