Hydration is one of the critical factors in improving and sustaining prime athletic performance. Athletes who consistently keep their bodies hydrated have been proven to have better results, as hydration prevents lactic acid production and continues muscle repair and recovery. Although water is a great liquid to maintain hydration, the addition of carbohydrates and electrolytes (composed of mainly sodium and chloride), which are the main ingredients in most sports drinks, have been demonstrated to be more efficient in transporting energy to muscles and prohibiting the disruption of digestion in the stomach. Furthermore, sports drinks are preferred over water during athletic activities, as the energy consumed is carbohydrates instead of protein and fat. In addition, electrolytes are one of the main components of sweat (the other component being water) in which they help with the intake of carbohydrates and water. Electrolytes provoke thirst as well, which may be dangerous, but as long as athletes are hydrated, they can avoid the possibility of hyponatremia, the condition resulting from excessive sodium. The research and knowledge on the positive impact of sports drinks portray that sports drinks can enhance athletic performance if utilized properly.
Precision Hydration Founder and Sports Scientist Andy Blow exhibits how the total solute concentration or tonicity of sports drinks can affect athletic performance. The tonicity of a solution can be subdivided into classifications of isotonic (approximately equal concentration than blood), hypertonic (more concentrated than blood), and hypotonic (less concentrated than blood). Each classification can influence the amount of carbohydrate (energy) an athlete’s body consumes, which supplies and restores the lost fluid when sweating occurs.
The most common sports drinks amongst athletes are isotonic. Popular brands such as Gatorade and Powerade are isotonic as they produce a moderate amount of energy in the body and are painless to the stomach. They are absorbed into the bloodstream relatively quickly, but not as fast as hypotonic solutions. Isotonic sports drinks are likely not to upset the stomach if they are not taken in huge quantities. Vast quantities of isotonic sports drinks can cause a bloated stomach, known as gastrointestinal upset, especially during endurance powered activities where more hydration is needed at rapid rates. For this reason, isotonic sports drinks are recommended to boost athletic performance during shorter workouts or events with higher levels of intensity, when the body needs large amounts of carbs, as isotonic sports drinks are “6-8% carbohydrate.”
Additionally, fewer sports drinks are hypertonic (acquiring “over 10% carbohydrate composition”) as athletes can get severely dehydrated if used in the wrong conditions. However, hypertonic sports drinks are great when athletes need to produce nutrients and consume calories to absorb into the bloodstream. When a hypertonic sports drink is consumed, the intestine in the stomach will also become hypertonic. Also, water tends to move to hypertonic solutions in general, so the water from the bloodstream goes straight to the intestine. This allows the solute concentration of the intestine to decrease in order for the body to produce nutrients. This decrease in free water in an athlete’s bloodstream may make them feel even more dehydrated than before! Therefore, athletes should only drink hypertonic fluids when they are not looking for hydration, but instead, looking for ample amounts of nutrient consumption during their meet or tournament.
Moreover, hypotonic sports drinks are the fastest in liquid intake into the bloodstream, but they do not give much energy (carbohydrates), as they are only “less than 6% carbohydrate.” Considering hypotonic sports drinks are less concentrated than blood, the liquid will always move towards a part of the stomach with a higher concentration. This process is powered by osmosis, where water molecules move through a semipermeable membrane from a space of lower concentration to a space of higher concentration. As a result, hypotonic solutions should not be consumed to gain more energy, but instead, for when an athlete needs an abundance of hydration during their athletic competition. In fact, most athletes will eat an energy bar or energy gels with their hypotonic sports drink to get the energy they need.
Although a sports drink’s tonicity can affect an athlete’s performance, there is not one type that is necessarily better than the other. Isotonic, hypotonic, and hypertonic sports drinks should be chosen based upon the athlete themself and the type of training necessary for their athletic competitions. Athletes should additionally note if they are looking for a drink that will hydrate them or produce energy to enhance and maintain their optimal performance. Along with hydration and energy composition, athletes should also keep in mind if they do not choose the concentration of their sports drinks wisely, it can have adverse effects on their performance.