Danielle Dunnagan, MS, RD, LD, Nutrition Care Division, Eisenhower Army Medical CenterWe've all seen the TV commercials portraying an athlete consuming a sports drink as a quick way to refuel after an exhausting practice. But what's really in a sports drink? Are they just for athletes? How did they become so popular?The sports drink industry started in 1965 when an assistant coach for the University of Florida football team took a particular interest in why the summer heat was affecting his players' performance at practice. The football staff decided to collaborate with a team of scientists at the university to determine a solution to their problem. The results of their research indicated that the football players were not adequately replacing carbohydrates, fluids or electrolytes following exercise and thus a product named "Gatorade" was developed.In general, sports drinks are typically a calculated blend of carbohydrates, electrolytes and water. Simplified, this translates to a water-based beverage with sugar, salt and sometimes a few extra micronutrients added in.Generally our bodies are comprised of approximately 60 to 70 percent water. We need water for digestion, energy and oxygen transport, and temperature regulation. We lose water every day, mostly through urination and perspiration (sweat), and it's up to us to replace it through what we eat and drink.However, sweat is made up of more than just water alone. We also lose sodium (salt), potassium and other micronutrients such as calcium and magnesium when we sweat. These nutrients, also referred to as electrolytes, are found in many of these foods we eat and help maintain fluid balance and assist in muscle and nerve regulation. Many Americans already consume more salt than what is needed in a day, therefore, it is important to be mindful about how much of these electrolytes are we consuming versus losing during exercise. Maintaining a balance of these electrolytes and water in our blood minimizes risk for dehydration. This is why sports drinks characteristically claim they contain added electrolytes for optimal hydration.That leaves only carbohydrates to explain. This nutrient is our body's main source of energy and can be found in a variety of foods and beverages such as grains, fruit, milk and even some vegetables. During exercise, our body's energy levels become depleted. These fuel levels, more specifically known as muscle glycogen stores, must be replaced by consuming carbohydrates (often found in sports drinks as sugar). Sugar is a "simple" or "refined" form of carbohydrate that provides easily available energy for our muscles but lacks any extra nutritional value. For this reason, it is important to remember that we can maximize our nutrition when refueling after exercise with whole and minimally processed meals or snacks such as a piece of fruit paired with a glass of milk.As a general guideline, sports drinks can potentially be valuable if exercise duration is greater than 60 minutes, or shorter but with higher intensity. Recommendations suggest to replace energy losses with 30 to 60 grams of carbohydrates per additional hour of exercise. Replace fluid losses with 2-3 cups of water per pound lost during physical activity. Water is probably sufficient for low- to moderate-intensity exercise or physical activity lasting less than one hour. Don't forget that sports drinks contain added sugar and salt, therefore, it is important to consume these beverages intelligently, reading and understanding the nutrition facts on each product's label.Sports drinks are not the only way to refuel following an intense workout. Food and other beverages can also be used to refuel the body. Fruit, grains, milk and yogurt are a few examples of dietary sources of carbohydrate that provide additional nutrition and aid in replenishing muscle glycogen and electrolyte losses. Add a moderate serving of protein for a more complete recovery snack or even a dash of salt, if sweat losses are high.Overall, sports drinks are specially formulated to help refuel muscles during or after high intensity exercise or physical activity lasting longer than one hour. Water is an excellent choice for most low- to moderate-level activities. Don't forget that sports drinks contain calories from carbohydrates and also have added salt.Use this information with your own judgment to determine if sports drinks might be a beneficial beverage for you.Sources: Clark, Nancy, MS, RD, CSSD. Nancy Clark's Sports Nutrition Guidebook. 5th ed. Champaign, IL: Human Kinetics, 2014. Print.U.S. Department of Health and Human Services. 2015-2020 Dietary Guidelines for Americans. Dec. 2015. Web. 19 April 2018."Gatorade. G Series Sports Drinks for Energy, Hydration and Recovery." Gatorade -- Heritage and History of Gatorade. Stokely-Van Camp, Inc, 2017. Web. 19 April 2018.