Sports drinks are a contentious issue for me.  Despite their assumed athletic relevance, they generally remind me more of consumerism and excess than they do of actual athletics.  I think of a specific Gatorade ad starring Kevin Garnett where he appears to sweat the color of his Gatorade.  I think about sports drinks’ bright colors and completely radical names that I always deliver in a certain way when I read them aloud.  Finally I think about sugar.  A 32-ounce bottle (pay attention to serving size when you read the label; the 32-ounce bottle in your hand is likely broken down into four servings) of a typical sports drink contains over 50 grams (13 teaspoons) of sugar and 200 calories.  Is this something I really need after a four-mile run on the trail by my house, even if it is a grueling uphill climb, switchback after switchback?

My contention with sports drinks isn’t that they don’t have a purpose, it’s that they’re generally overconsumed and overhyped.  I can’t help but think that sales figures are sports drink manufacturers’ biggest concern, but Kevin Garnett’s bellow seems to scream otherwise.  What’s the reasoning behind the typical sugar, water, and electrolyte composition of these drinks?  When, if at all, does it become important to rehydrate with something other than water?  What, beyond the commercial viability of selling sugar water, are the real benefits to professional athletes and amateurs alike?

The Formula

Sports drinks are generally made of water, various simple sugars like glucose and fructose, and electrolyte-containing ingredients like salt, citric acid, sodium citrate, and potassium sulfate.  The theories behind the inclusion of these ingredients are seemingly straightforward.  Water is necessary for hydration and proper temperature regulation.  Sugar is a carbohydrate and is a quick source of energy.  Electrolytes are lost when you sweat and are integral for many bodily processes including maintaining proper fluid balance and nerve and muscle functioning.

Every Athlete is an Individual

Sweating is an important process for body temperature regulation.  Unfortunately, my body sucks at temperature regulation.  Post-run you’ll find me with a bright red face and just a little dew about my temples and in the middle of my back.  My husband, however, sweats so much it drips off of his bandanna.  We both just ran the same trail, the same distance, and at the same pace, but our bodies’ reactions are not the same.  Evidence shows that we all lose fluids (and with them electrolytes) at different rates during exercise and beyond that, even the composition of sweat differs from person to person.^{1, 10} These differences are determined due to environmental conditions, clothing choices, fitness level, diet, age, gender, and use of certain medications, among many other factors.² It seems logical to replace these lost electrolytes, but evidence shows that the body is generally able to cope with and adjust to these losses by relying on dietary stores.⁸

Fluid and Electrolyte Balance

Dehydration stresses your body and decreases athletic performance, so before beginning exercise of any intensity level, make sure you are hydrated.  Those who are faster, heavier, and in warmer environments generally need additional fluids over their smaller, slower counterparts who are in cooler climates.  Preceding your athletic endeavor, it is typically sufficient to eat regularly and drink water throughout the day.⁸ While exercising, it is ideal to drink fluids at a rate to keep weight loss under 2% of total body weight (weigh yourself pre- and post-exercise to determine your water loss). ^3,8 The amount of liquid necessary to stay within this range will vary depending on your personal rate of sweating.

While the effects of dehydration are clear-cut, the effects of exercise-induced electrolyte loss are a bit more convoluted. If you pay close attention to the claims sports drink manufacturers make as a means to sell their products, they avoid specifically mentioning the idea that replacing electrolytes will improve performance or even rehydrate you more quickly.  They simply point out the following facts: you lose electrolytes when you sweat, electrolytes are important for various bodily functions, and electrolytes (sodium in particular) stimulate thirst.¹¹

These are accurate statements, but the marketing implication seems to be that because of these things, replacing electrolytes has an actual impact on athletic performance.  The Institute of Medicine states that, “Because substantial quantities of sodium, chloride, and to a lesser extent, potassium are lost in the sweat during prolonged exertion, especially in the heat, many are concerned that this electrolyte loss should be replenished during exercise to maintain the appropriate distribution of electrolytes in the various fluid compartments of the body.  However, there is little direct evidence of a beneficial effect of electrolyte replacement for any but a small proportion of endurance athletes.³“  In other words, replacing electrolytes during a four-mile run probably isn’t going to make me any faster, better, or stronger.⁹ Also, you don’t need to rely on specially-formulated drinks to replace electrolytes. Electrolytes like sodium, potassium, magnesium, and calcium, are naturally found in many foods, such as fruits, vegetables, and sea salt.  In short-duration activities your body is able to draw on its own stores to balance itself.

Regardless of athletic impact, electrolyte inclusion has a definite positive aspect.  Research shows that small amounts of sodium chloride (salt), an electrolyte, increase the palatability of beverages.^{2, 3, 10} If enjoying drinking a beverage increases the amount a person drinks, then the inclusion of electrolytes might be an important factor for making sure you drink enough water to stay sufficiently hydrated during and after exercise.

While it’s highly important drink adequate fluids before and after exercise, you can actually drink too much water.  Normally the body adapts to increased water intake by increasing urine output.  This stabilizing effect is less efficient during exercise, however, so if you are sweating heavily for extended periods of time (such as marathons or ultra events) and drinking only water, it’s possible that you’ll end up with too much water in relationship to electrolytes, sodium in particular.  This is known as water intoxication or hyponatremia, and the result can be irregular heartbeat, swelling of tissues, and even coma or death.

Carbohydrate Content

It turns out that the part of sports drink I scoff at the most, the carbohydrate (sugar) content, has actually been shown to improve athletic performance and increase endurance when used after an extended duration of activity.^3,4 Specifically, research shows that using a carbohydrate-containing sports drink at least 30 minutes before you expect to be fatigued can delay the onset of fatigue.^3,8 It is important to note, however, that the body has adequate blood glucose and stored glucose (glycogen) to maintain energy for several hours of sustained athletic activity (generally believed to be about three hours).⁷ Ask yourself how often you exercise for several hours or more and what you’re trying to accomplish with exercise.  If you are of the camp that’s using physical activity to lose weight, you might want to reconsider adding calories that your body doesn’t really need.

Water vs. Electrolyte Drinks

Consider the following questions:  Are you hydrated before you start exercising?  How much do you sweat?  How long and at what intensity are you exercising?  Will you drink plain water or do you need to be enticed by something a little sweet and salty?

Short duration (less than 3 hours) and well hydrated?  Choose water.

Not much of a water drinker, exercising at high intensity (where you would benefit from an easily-digestible carbohydrate boost) or for three hours or more?  Try our sports drink recipes; they use antioxidant and nutrient-rich whole fruit, unprocessed sea salt (rich in electrolytes and trace minerals), and taste far less syrupy-sweet than commercially-available sports drinks.

Mango-Citrus Electrolyte Drink

• 32 oz water
• 1 Tbsp lemon juice
• 1 Tbsp raw apple cider vinegar (try Bragg’s)
• 1/4 tsp baking soda
• 1/8 tsp sea salt
• 1 cup mango, fresh or frozen

Mix all ingredients in blender.  Strain.  Chill until cool.

Nutrition breakdown:

calories: 110
carbohydrates: 29.4 g
sugar: 24.8 g
sodium: 608 mg
potassium: 286 mg
magnesium: 14 mg
calcium: 17 mg

Berry-Citrus Electrolyte Drink

• 32 oz water
• 1 Tbsp lemon juice
• 1 Tbsp raw apple cider vinegar (try Bragg’s)
• 1/4 tsp baking soda
• 1/8 tsp sea salt
• 1 cup mixed berries (any combination of strawberries, blueberries, blackberries, and/or raspberries), fresh or frozen
• 1 Tbsp honey

Mix all ingredients in blender.  Strain.  Chill until cool.

Nutrition breakdown:

calories: 151
carbohydrates: 40.2 g
sugar: 32.5 g
sodium: 606 mg
potassium: 153 mg
magnesium: 8 mg
calcium: 10 mg

^{1 Kilding, AE, et al. (2009). Sweat rate and sweat electrolyte composition in international female soccer players during game specific training. Int J Sports Med 30(6) 443-7.
2 Sawka, MN, et al. (2010). Exercise and fluid replacement, from Medscape http://www.medscape.com/viewarticle/717055_5
3 Marriott, BM (1994). Fluid replacement and heat stress. Institute of Medicine, Food and Nutrition Board, Committee on Military Nutrition Research.
4 Gisolfi, CV (1993). Use of electrolytes in fluid replacement solutions: What have we learned from intestinal absorption studies? University of Iowa, Iowa City.
5 Irving, RA (1991). Evaluation of renal function and fluid homeostasis during recovery from exercise-induced hyponatremia. Journal of Applied Physiology 70(1) 342-348.
6 Greenleaf, JE, et al. (1996). Mechanisms controlling fluid ingestion: thirst and drinking from Body fluid balance: exercise and sport.
7 Armstrong, LE, et al. (1999). Fluid-electrolyte balance during labor and exercise: concepts and misconceptions. Int J Sports Nutrition 9(1) 1-12.
8 Latzka, WA, et al. (1999). Water and electrolyte requirements for exercise. Clinical Sports Med 18(3) 513-24.
9 Coombes, JS, et al. (2000). The effectiveness of commercially available sports drinks. Sports Med 29(3) 181-209.
10 Maughan, RJ, et al. (1997). Recovery from prolonged exercise: restoration of water and electrolyte balance. J Sports Science 15(3) 297-303.
11 (26 Aug 2010). Gatorade website, frequently asked questions, science and nutrition http://www.gatorade.com/frequently_asked_questions/default.aspx}

Tags: athletes, athletics, Carbohydrates, drink, electrolytes, energy, recipe, sports, sugar