Sports drinks are used to supplement the loss of electrolytes, water and energy after exercise, helping the athlete to recover faster by replacing key ionic substances in the body. . They are designed to give the athlete an equal amount of carbohydrates and fluids to provide almost instant rehydration and refueling during physical activity. This essay will explain the purpose of the contents of sports drinks and their uses in the human body. There are three main types of sports drinks: Isotonic, hypotonic and hypertonic. A hypotonic drink will contain a lower concentration of sugars and electrolytes compared to a human body, meaning it will be absorbed more quickly than water. They contain more solvent than solute, which means they would be less concentrated than inside a cell. Most sports drinks are classified as isotonic, meaning that the concentration of electrolytes is similar to that found inside cells, they will be absorbed at the same rate as water. These drinks contain equal amounts of solute and solvent, which means they will be equal to those contained in a cell. And finally Hypertonic, there are some where the concentrate is greater than that found in human bodily fluids. Hypertonic drinks have the slowest absorption rate but offer the highest dose of energy of the three. This drink contains more solute than solvent, resulting in a more concentrated solution. Sports drinks should contain 4 to 8% (4 to 8 g/100 ml) carbohydrates and 23 to 69 mg/100 ml sodium (American College of Sports 2007) to provide the best amount. fluid and fuel delivery. Studies have shown that sports drinks containing protein and amino acids (at a concentration of 2%) provide superior recovery in specific exercise scenarios. (Stearns et al. 2010) Carboh...... middle of document ......AA, 2013) But which drink to use depends on what you want to achieve through physical activity. If you're trying to exercise to lose weight, or doing it in short bursts (about 1 hour), water is the way to go. For most people, “their fluid needs can be met by water” (Professor Clare Collins, DAA, 2013), and they generally will not sweat enough to lose many electrolytes. On the other hand, if you are an athlete and need to perform for a longer period of time, sports drinks are the way to go. When exercising, muscles use carbohydrate stores for fuel. These reserves will run out after about 90 minutes, after which fat will be used instead. Fat is not an effective source of energy and performance will drop indefinitely. Carbohydrates in sports drinks help athletes stay at their best for longer periods of time..