"Your Sports Drink may be dehydrating you" article

[swlsue]

I thought this was an interesting article

I recently re-vamped my nutrition program to address my cycling needs. One of the questions I had for my nutritionist, Keith Klein, was whether or not I needed to drink Gatorade. This article parallels the information he gave me on sports drinks.

It's from the Lee Labrada site.


Your Sports Drink May Be Dehydrating You

by Dr. Clay Hyght, DC, BSc, CSCS, CPT

With summer rapidly approaching, Lee Labrada and I want to drive home the importance of proper hydration. A few weeks ago Lee wrote a greatarticle on the importance of proper fluid intake and what detrimental effects dehydration can have. I want to go into a little more detail about how to optimally rehydrate yourself. First let me recap a couple of things.

A trained athlete can lose up to 3 liters of fluid per hour. Think about that for a moment. Picture a 3-liter container of Coke (there should not be one in your kitchen!) Now imagine sweating that much in one hour. That’s a lot of fluid lost from your body that needs to be replaced. For every 450 ml of fluid lost during exercise, you will lose about one pound of bodyweight. In other words, if you lose four pounds during your workout, you have lost almost 2 liters of fluid. With that amount of fluid loss, the body losses some of its ability to maintain its ideal core temperature, usually 98.6 degrees Fahrenheit. Muscular strength and endurance begin to decrease as well. With the above information and Lee’s article, you should now fully understand the importance of staying properly hydrated.

If you watch any Television at all, you probably think that the best way to replenish this lost fluid is by drinking a “high tech” sports drink like Gatorade or PowerAde, right? Wrong. These drinks are about as high tech as a phone made with two tin cans and a string in between. (There goes my chance for a big Gatorade endorsement contract.) The primary problem with these drinks is that they are too concentrated.

Now I need to go over a little physiology. Normally, physiology is about as fun as watching paint dry. So, for me to avoid putting you to sleep, why don’t you go take a Charge! capsule, then come back and read the rest in 30 minutes or so.

Welcome back. Now allow me to continue: The osmolarity of your body fluid is approximately 300 (milliosmoles per kilogram). A rehydration beverage needs to have an osmolarity lower than that of your body. In English, the concentration of the beverage should be less than the concentration of your body’s fluid. If it is not, and you drink a beverage that is more concentrated than your body’s fluid, your body will have to bring fluid into your intestinal tract from your blood stream in order to decrease the concentration of the fluid so that it can be absorbed. That’s exactly the opposite of what you want to do. You’re trying to get water into the bloodstream, not out of it. Drinking a concentrated beverage to rehydrate yourself is kind of like using water to put out a grease fire; it seems like it would work but it actually makes the problem worse.

A rehydration beverage should contain no more than nine grams of carbs per 8 oz serving. This will help to ensure that the osmolarity of the beverage is lower than that of your body. This is an over-simplified rule of thumb, but without going into molecular weight of different molecules and their effect on osmolarity and osmotic pressure, it will suffice. If you want to get a tad more complicated, you can look for a beverage that contains glucose polymers (maltodextrin) as the primary ingredient instead of sucrose, glucose, or high fructose corn syrup. The larger maltodextrin molecule does not raise the osmolarity of the solution as much as the smaller molecule sugars like sucrose.

Due to the fact that a substantial amount of electrolytes (sodium, potassium, magnesium, and calcium) can be lost with prolonged activity, it’s important that your beverage of choice have electrolytes added. So, what is a good beverage for rehydration that has an osmolarity of less than 300? Pedialyte. Yeah, the wimpy baby-with-diarrhea-drink is far better than macho man Gatorade is! Sorry to burst your bubble. Pedialyte is specifically formulated to have an osmolarity of about 270 for optimal rehydration. If you’re not secure enough in your manhood to drink Pedialyte, you can dilute your sports drink by half or more to reduce the osmolarity. Keep in mind though, that you’ll dilute the electrolytes also. Eight ounces of Pedialyte has 187 mg of potassium while Gatorade has only 30 mg in its concentrated form. Dilute it by half and you’re down to 15 mg. That’s not so “high tech” after all. The ideal drink would have specific amounts of magnesium and calcium as well. However, to my knowledge, this has not yet been made commercially available.

Sifting through marketing hype can be tough. What we are led to believe is the latest and greatest is not always so. My goal is to help you filter out the nonsense and hearsay and get down to what is scientifically valid. Training and eating right are hard enough without wasting time on things that don’t work.

[Technotart]

YES YES YES!!!!!

Pedialyte is excellent for rehydration and the article is RIGHT ON THE MONEY!!! That is why, when you drink sports drinks you get THIRSTIER!!!

Pedialyte comes in flavors that are more palatable than the plain, and there are cheaper store brands available. It's usually in the baby food section at the grocery store.

[oroight]

Do you have "endura" hydration formula, with mag and calcium?

[runnergirl]

I have to say the the combative tone of the article is highly off-putting, I think the author would reach more people with a calm, reasoned argument. I agree gatorade is not great for endurance sports, it's just too sweet, and there's not enough sodium.

Pedialyte is too expensive though, I use the Clif electrolyte replacement (lemonade flavor), it's got a ton of potassium and sodium and isn't so sickeningly sweet. It's also organic, and at $15 for a giant canister of powder is much more reasonable than some of the other powders out there.

[Technotart]

The store brands of pedialyte are MUCH cheaper - a couple of bucks. They are the same as the pedialyte though.

[SimpleCycle]

Does pedialyte come in a powdered form, or do you have to buy the pre-mixed kind?

E-caps makes a straight electrolyte replacement called Endurolytes. You can take them as capsules or mix the powedered form into your water, although the end result tastes like salt water.

My question is, if you can only consume x grams of carbohydrate without dehydrating yourself, how do you keep yourself from bonking? On long rides, you need both sufficient hydration and nutrition. No matter what, you're going to increase the concentration of carbohydrate in your stomach at some point, and will need water to digest that. It's unavoidable. I wish he's explained a little more about how the maltodextrin figures into the equation.

A friend of mine got hyponatremia drinking Powerade on a hike of the grand canyon. The ER doc said they've taken to calling it "Powerade syndrome" because Powerade has so little sodium - less than half that in Gatorade. It never occurred to me that even in the commercial grocery store drinks, there can be a substantial difference.