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What You Should Know When Choosing a Sports Drink
by Thomas Incledon, MS, RD, LD, CSCS
The Hydration Hype
The advertisements on television showing the sweaty athletes drinking the beverage of their choice always leaves questions in our minds about what the best drink is, how much to drink, when to drink, and if any of the commercial drinks are based on science or just marketing. Fortunately, there is plenty of scientific research regarding fluid replacement for survival in extreme temperatures, for prevention of heat-related illnesses, and for improved sports performance. In this article I'll explain why the body needs fluid, how to determine your fluid loss during exercise, and what to look for in a fluid replacement drink. So sit back, grab the beverage of your choice, and get hydrated!
Water, Water, Everywhere
Our total body weight averages about 60% water, which is equal to approximately 42 liters. This water is divided into two major compartments in the body,
extra cellular and intracellular fluid. The extra cellular
fluid, equal to about 14 liters, is the fluid outside the cells and mostly consists of plasma, the liquid portion of the blood. Intracellular fluid, about 28 liters of the bodies water weight, is located inside the cells. Blood itself contains
extra cellular fluid from the plasma and intracellular fluid from the red blood cells. When our bodies try to cool down during exercise, sweat is produced. Approximately 10% of the water in sweat comes from the plasma, and if this loss increases, it can be detrimental to circulation, nutrient delivery, work capacity, and thermoregulation. Fluid replacement maintains blood volume for circulation, which is also necessary to continue sweating in order to dissipate heat. So you can see how important water is to our entire body. In addition to the water lost in sweat, the electrolyte sodium, which stimulates the thirst mechanism and helps retain urine, is also lost. But that's not all. During endurance exercise that lasts more than one hour and even during brief, intermittent, exercise our bodies use and deplete carbohydrates. This is another important factor to consider with fluid loss during exercise since carbohydrates are both a source of water and energy.
Why Don't We Drink To Our Health?
Our bodies maintain normal hydration on a daily basis by drinking when our thirst stimulus is activated. However, in some physiological and psychological stress conditions, quenching our thirst mechanism isn't enough to keep us fully hydrated. This is called involuntary dehydration. It is because of this syndrome that adding salt to fluid replacement drinks has been advocated. The addition of salt will stimulate the thirst mechanism to encourage more drinking, improve the taste of a fluid replacement drink, allow the body to retain the water it already has, and replace what was lost in sweat. This becomes especially important if a well-balanced diet is not followed. Since the losses of electrolytes from sweat are minimal, they can be fully replaced in a normal meal, and therefore, adding sodium chloride to a drink is not necessary.
How Much Fluid Do You Lose?
It is well accepted that exercise and heat stress produce high rates of fluid loss which can be as much as 2 liters per hour. The research on fluid replacement states that you should replenish exactly what you lose, and maybe even up to 150% more. But fluid amounts will vary from person to person and even from day to day, so it's important to determine just how much you are losing. Weighing yourself daily before exercise and then after exercise is a very practical way to determine your fluid loss. The rule of thumb is "ounce for ounce." For every ounce of weight lost, drink an equal amount of fluid. Watch your fluid loss carefully, especially if you are exercising in high heat and high humidity with high intensity. If your body weight loss exceeds 4% of your original weight, you should reduce the intensity and duration of your exercise.
The Perfect Fluid Replacement
So the debate is whether to drink a sports beverage, or just stick with Mother Nature's recipe and chug plain old water. There are definitely benefits to both schools of thought. Water is infinitely less expensive and readily available. In terms of thermoregulation and survival, water will not let you down. On the other hand, the American College of Sports Medicine (ACSM) recommends adding carbohydrates (30-60 g/hour in a concentration range of 4-8%) to fluid for exercise that lasts longer than one hour, since the correct proportions will not harm water delivery to the body and may enhance performance [6]. They also maintain that the addition of sodium (.5-.7 g/L of water) will enhance the taste of the drink and increase fluid retention. Commercial sport beverages try to compromise on ratios between what can give the best fluid replacement and still provide the most carbohydrates. Many of the sport beverages on the market contain the appropriate ratios, but you should always read the labels.
Ingesting too high of a carbohydrate concentration will delay water entering your system and may lead to dehydration. Eating nutritionally balanced meals and drinking fluid throughout the day cannot be emphasized enough. You should always prepare your body with adequate nutrients and fluids prior to exercise, and continue to consume fluid throughout exercise, so your body is never working at a deficit. Try to drink about 17 ounces of fluid 2 hours before exercise and drink on a schedule at regular intervals because the thirst mechanism isn't very reliable for adequate hydration. But don't go overboard with the water, either. Studies have shown that maintaining a
hyper hydrated state, either by ingesting glycerol or abundant amounts of water, isn't any more beneficial for thermoregulation or performance than maintaining euhydration, or a normal fluid balance. Don't forget, though, that even a small amount of dehydration can increase cardiovascular strain and make it difficult for your
body to dissipate heat. This affects not only performance issues, but life and death issues as well.
Do I need sports drinks?
When you're sweating your way to a serious thirst, water isn't always enough. That's why old-time American ranchers used to drink batches of switchel -- a mixture of water, molasses, and vinegar
during haying season. Workouts have changed since then, and, thankfully, so have the energy drinks. The water is still there, but the molasses and vinegar have been replaced with some form of sugar, minerals such as potassium and sodium, and the ever-mysterious "natural flavors." The end result is basically the same: a double shot of water and muscle food when you need it most.
There's no doubt that sports drinks can help you get through a long, hard workout. (If you're exercising for less than one hour straight, plain water works as well as anything else.) Despite all the talk in commercials about "electrolyte balance," the real value of these beverages lies in the carbohydrates: Sugars and other energy compounds help feed the muscles and delay fatigue. But according to a recent report in the journal Sports Medicine, added sodium and potassium won't do you much good unless you're sweating profusely for more than four hours (think triathlon).
One consideration for some people is the caloric content of these drinks. If you're trying to lose weight, a 70-calorie quaff means you have to cut back somewhere in your day's diet. If you do this by limiting yourself to one small serving of meat at dinner, great. But if you know you compensate by shunning the fruit bowl, think again about what your body needs most.
How should I use sports drinks?
Try taking a few gulps in the early stages of your workout. The goal is to prevent dehydration, not to cure it. Begin with 8 ounces 20 minutes before you start exercising, then drink four to six ounces (half the amount of liquid in a can of soda) every 15 to 20 minutes; that should be enough for most types of exercise.
Which sports drink should I choose?
In terms of ingredients, there's little to distinguish the three major brands of sports drinks: Powerade, All Sport, and Gatorade. As you can see from the comparison below, the big three are nearly identical in nutritional content, although All Sport has a few extra vitamins. In addition, Gatorade has twice as much sodium as the other brands (which you probably don't need) and fewer calories. (Gatorade adds the extra sodium to stimulate the thirst mechanism.)
A few other sports drinks have tried to find a place in the market by offering athletes a little something extra. For instance, both Extreme Ripped Force and Recharge Plus are laced with chromium. (Contrary to widespread belief, there's no clear evidence that extra chromium helps build muscle or speed weight loss.)
Unfortunately, some of the extras may be dangerous. Extreme Ripped Force contains ephedra (ma huang), a powerful herbal stimulant that can cause nervousness, insomnia, nausea, spikes in blood pressure, and even heart attack and stroke. One bottle of Extreme Ripped Force contains 24 milligrams of ephedra's active ingredient, three more times than the amount the FDA recommended in its 1997 guidelines (which are now under revision). This product also throws in 200 mg of caffeine (almost as much as a 12-ounce cup of coffee contains), making it a poor choice for anyone who wants a jitter-free workout.
Aside from watching out for ephedra and other potential hazards, perhaps the most important factor in your choice is taste. If you find a drink that you enjoy guzzling, you're much more likely to get enough of it.
To help you pick your drink, here's a comparison of six brands. Note that the nutrition information is for an 8-ounce serving; you may well drink more than that during a long workout. Also, remember that the taste-test results are not objective: Your preferences -- as well as the prices at your local store -- may vary.
All Sport
Size: 34 fluid ounces Price: $1.29 Label highlight: "All Sport isn't just a thirst quencher, it's a body quencher." Main ingredients: Water and high-fructose corn syrup Nutrition (8-ounce serving): 70 calories, 19 grams of sugar, 1 gram of other carbohydrates, 55 mg of sodium (2 percent of RDA), 50 mg of potassium (1 percent of RDA), and 10 percent of the RDA of thiamine, niacin, vitamin B-6, vitamin B-12, and pantothenic acid.
Taste test (fruit punch): Fruity and very sweet. Wouldn't be out of place at a Kool-Aid stand.
Taste test (lemon lime): Much like a flat, slightly watered down lemon-lime soft drink.
Gatorade
Size: 32 fl oz Price: $1.29 Label highlight: "Millions of prizes" (none won by taste tester) Main ingredients: Water and sucrose syrup Nutrition (8-ounce serving): 50 calories, 14 grams of sugar, 1 gram of other carbohydrates, 110 mg of sodium (5 percent of RDA), 30 mg of potassium (1 percent of RDA), and no other vitamins and minerals.
Taste test (fruit punch): Thin fruit taste, sour, slightly bitter aftertaste.
Taste test (lemon lime): Somewhat bitter and salty. The sodium is quite perceptible. Only a faint hint of citrus.
Powerade
Size: 20 fl oz Price: $0.95 Label highlight: "Any sport, any team, any game" Main ingredients: water and high-fructose corn syrup, plus natural flavors of kiwi, melon, and pineapple Nutrition (8-ounce serving): 70 calories, 15 grams of sugar, 4 grams of other carbohydrates, 55 mg of sodium (2 percent of RDA), 50 mg of potassium (1 percent of RDA), and no extra vitamins or minerals.
Taste test (fruit punch): Like slightly watered down Hawaiian Punch. Slightly tart, not very sweet.
Taste test (Green Squall): Glows like antifreeze, tastes tart and fruity. More flavorful than the lemon-lime drinks.
Extreme Ripped Force
Size: 18 fl oz Price: $1.95 Label highlight: "The extreme hyper-thermogenic drink" Main ingredients: Water, maltodextrin, crystalline fructose, natural and artificial flavors, plus "extras" such as caffeine and ephedra Nutrition (8-ounce serving): 53 calories, 6 grams of sugar, 7.5 grams of other carbohydrates, 40 mg of sodium (2 percent of RDA), 84 mg of potassium (2 percent of RDA), almost half of the RDA of niacin, 35 percent of the RDA of chromium, and no significant amount of any other vitamin or mineral. Note: This drink contains far more ephedra (an herbal stimulant) than the FDA considers to be safe.
Taste test (fruit punch): Strongly sweet and fruity (in a somewhat artificial-flavor sort of way). Goes down smoothly. Leaves a slight aftertaste.
Taste test (lemon lime): Sour and slightly bitter. Tastes like a cheap diet soda without the carbonation.
Recharge Plus
Size: 32 fl oz Price: $2.47 Label highlight: "Excellent source of vitamin E, selenium, chromium picolinate (compared to Recharge)" Main ingredients: water, concentrated fruit juices, natural flavors Nutrition (8-ounce serving): 80 calories, 16 grams sugar, 2 grams other carbohydrates, 25 mg of sodium (1 percent of RDA), 85 mg of potassium (2 percent of RDA), full day's supply of vitamin E, 25 percent of the RDA of selenium, 80 percent of the RDA of chromium, and no significant amounts of other vitamins or minerals.
Taste test (berry juice): Fruit flavors are more genuine than in other sports drinks. Tart and sweet. A slight aftertaste.
Taste test (lime): Smells pungent and sour, and doesn't taste much better. Has a slightly metallic aftertaste. Definitely leads the sports drink pack in unidentifiable white sludge.
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