According to G-push, body fluid has a critical role in exercise as blood carries oxygen and nutrients such as glucose to the muscles where they are needed for energy metabolism. The blood also removes metabolic waste from energy production. Hormones, which regulate muscular activity and metabolism are also carried in the blood. Blood pressure, which affects the functioning of the heart is affected by blood plasma volume. A reduction in blood plasma volume causes a reduction in blood flow to the muscles and skin, causing fatigue. Therefore, it is essential that athletes consume enough water during exercise if they are to avoid fatigue, heat cramps, a rise in body temperature as the body would not be able to sweat enough to cool it down, heat exhaustion and the possibility of heatstroke.
Hydration drinks have the highest quantity of water. G-push states that the principle purpose of these drinks is to get fluid into the body quickly. They have a low carbohydrate content to allow the fluid to empty quickly from the stomach and for it to be quickly absorbed. Sodium is also an important ingredient in hydration drinks as it assists the transfer of water and sugar to the blood. There is a small amount of carbohydrate in the drink. However, this is not significant enough to replenish depleted glycogen over a sustained period of time. This type of drink is suitable for shorter periods of exercise, for pre-race hydrating and for maintaining hydration but not energy over a longer period of time.
The second most important ingredient of a sports drink is carbohydrate, according to Dale Brigham. Carbohydrates in sports drinks are usually in the form of sugars such as glucose, fructose and sucrose or in the form of short-chain starches such as maltodextrins. The website states that sports drinks designed for use during exercise usually contain more than one type of carbohydrate. The better-formulated drinks usually contain both simple carbohydrates such as glucose and fructose and complex carbohydrates such as maltodextrins, and usually contain more complex than simple carbohydrates.
According to the website , carbohydrates are important to athletes as carbohydrate is the most efficient source of energy because it does not require as much oxygen to be burnt as both protein and fat do. During exercise the muscles need to increase their uptake of blood glucose and so to prevent blood glucose levels from falling, the liver produces glucose from the liver stores. Because of this, the body's glucose stores are gradually depleted, resulting in reduced performance. Therefore it is necessary for athletes to top up their glucose levels by consuming products containing carbohydrates to enable them to carry on performing at their best. Athletes need to consume carbohydrates before, during if they are competing or exercising for long periods of time and after exercise to stop their blood glucose levels from falling too low and to maintain the body's glycogen stores. Many athletes cannot consume food before exercise and therefore they need to rely on sports drinks for their carbohydrate needs.
Although we can get more energy per gram of fat than we can per gram of carbohydrate, fat is stored in the body as different compounds. G-push say that the process of breaking down these compounds into usable fatty acids requires energy and it takes more oxygen to get one kcal of energy from fat than it does from carbohydrate. Therefore carbohydrate is the preferred energy source for exercise.
According to , protein can also be used as an energy resource but it is limited and inefficient. At rest the body uses very little protein for energy, but during exercise protein can provide up to 10% of the energy requirement for prolonged exercise. Protein can be used for energy because some of the amino acids in protein can be converted in the liver through the process of gluconeogenesis to provide glucose. Protein yields approximately 5.2kcal/g more than glycogen, but provides less energy than fat. However, protein is not thought of as a potential energy source because of the time taken for digestion and absorption.
Hypoglycaemia occurs when the body’s muscle and liver glycogen is almost depleted and fat is the only thing to maintain blood sugar levels. This causes physical performance levels to decline fast. Therefore it is very important that athletes consume energy products such as sports drinks to maintain their blood glucose levels before, during and after exercise.
The main aim of sports drinks is to provide carbohydrate through different sugars, and according to the website , the average sports drink is approximately 8% carbohydrate. Sugars are broken down quite quickly into monosaccharides, allowing the body to maintain the glucose supply to the muscles. Scientific research has also lead to show that a mixture of carbohydrates such as the combination of glucose and fructose, allows oxidisation to happen more quickly than pure glucose. It is thought that the combination of glucose and galactose will provide a greater amount of energy.
According to G-push, energy sports drinks contain the highest amount of carbohydrates and are designed to primarily replenish lost glycogen and to provide rapid blood glucose. Recovery drinks also contain a high amount of glucose, but are designed to rebuild the glycogen in the muscles and liver after exercise. There is evidence that an athletes recovery period can be significantly reduced if an appropriate drink is consumed within the first one and a half hours after exercise.
Sodium is another component needed in a sports drink which Dale Brigham says is the third most important ingredient, although it is said that many sports drinks do not contain enough. According to G-push, sodium is needed by the body to enhance fluid absorption in the gut, to maintain plasma volume, to replace salt lost in sweat, improve the palatability of the drink and to stimulate the thirst mechanism. Too little sodium in the body results in a condition known as hyponatremia that can be more dangerous than dehydration. If this is untreated it can lead to muscle cramps, cold, pale skin and possibly death. Scientists believe that optimum sodium levels are around 170-180mg of sodium per 8 fl oz. However, very few sports drinks on the market contain these levels of sodium because it is difficult to disguise the taste.
Discussion and Conclusion
This research shows that the use of sports drinks before, during and after prolonged exercise can enhance an athlete's performance. Most of the top athletes use sports drinks to enhance their performance, along with many amateur athletes who tend to use the cheaper brands of sports drinks to suit their needs.
Sports drinks are preferred by athletes to water because water causes bloating, suppresses thirst, and stimulates urine output and therefore is inefficiently retained. Water also does not include carbohydrates or sodium plus other minerals that the body requires. The three main problems for athletes are that they can become dehydrated, lack energy and so their performance becomes limited and their bodies lack sodium because it is lost through sweat. Sports drinks aim to solve these three problems.
The information gained from G-push shows that the best way to keep hydrated during prolonged exercise is to consume carbohydrate alongside water and sodium. Water by itself is not sufficient to keep an athlete hydrated because water will diffuse through to the cells more quickly if glucose and sodium are also present. This means that the consumption of sports drinks will enable athletes to stay hydrated more easily than if they drink plain water, and so their performance will be enhanced.
It is important that athletes keep hydrated to allow them to perform to a high standard. If their body becomes dehydrated they may suffer from reduced blood plasma volume resulting in a reduction of blood flow to the muscles and skin and therefore they will become fatigued. The graph below, taken from , shows the reduction in performance levels as an athlete becomes dehydrated.
This backs up the idea that the consumption of sports drinks is needed for athletes to keep hydrated during long periods of exercise.
The research has shown that sports people need to take in carbohydrate as this is the most efficient type of energy. This is because it does not require as much oxygen to be burnt as protein and fat. The body does not have sufficient glucose supplies to allow an athlete to take part in prolonged exercise without it being topped up. Therefore if glucose supplies run out, fat and protein will be used to allow the athlete to keep performing. However, they are not able to do this for a long period of time as hypoglycaemia will occur. For these reasons, if athletes want to take part in prolonged activities and perform at their best, it is essential that they consume carbohydrates before exercise to build up their glycogen stores, during exercise to top up their glycogen stores and after exercise to rebuild their glycogen stores and to aid their recovery.
Sodium is another important ingredient which enables an athletes performance to be enhanced because it is lost through sweating and therefore needs to be replaced. A reduction in sodium levels can result in hyponatremia and can lead to cramps, cold pale skin and possibly death. It is therefore vital that athletes top up their sodium levels and a good way to do this is to consume sports drinks containing sodium.
A sports persons diet may need to be extremely high in carbohydrate. However, this can involve consuming a large amount of food. Therefore sports drinks can help them consume the quantity of carbohydrate that they need without providing much bulk. Athletes at all day events may find it difficult to obtain nutritious food and so sports drinks can provide them with a quickly digestible source of nutrients.
The research supports the idea that the consumption of sports drinks can enhance performance due to the body's need for the ingredients during prolonged exercise to enable it to function to a high standard. Therefore sports drinks are a huge benefit to athletes.
Appraisal
The study was successful in finding out how sports drinks can enhance an athlete's performance. There was a lot of information available on the Internet concerning sports drinks and how their ingredients affect the body, allowing me to research sports drinks in a lot of detail. There was also information available from textbooks and articles and so a wide range of sources was used. The study fits in with the syllabus for unit six of the A2 course, and so it will be useful to refer back to in the future. It closely followed the plan with everything in the plan being included in the study.
A weakness of this study is that I did not contact different sports drinks companies or any sport s organisations for information concerning sports drinks. However, I did use G-push's website to gain information about their products and sports drinks in general. If I were to carry out this project in the future I would write to sports drinks companies to gain information on their products and also contact sports organisations to find out how sports drinks are used in their area of sport. Another thing that I would do if I were to repeat the study would be to find more articles about sports drinks and also to gain peoples views about them, allowing me to find out if athletes agree that sports drinks enhance their performance.
If I were to carry out another study at A2 level related to this study, an idea would be to carry out an investigation using sports people. This could involve asking them to consume different sports drinks on different occasions but in the same setting and seeing which ones enhance their performance the most. The ingredients of the drinks could then be studied to find out what combination and quantity of each ingredient enhances their performance the most. This would probably be different for each sport and so it would be good to use performers from different sports in the study so that the drinks used to gain optimum performance for each athlete can be compared.
Overall, the study has been successful in researching and reaching the aim of the study, although a few improvements could be made if the study was to be carried out in the future.
Bibliography
Books
Galligan, F, Maskery,C, Spence, J, Howe, D, Barry, T, Ruston, A, Crawford, D (2000) Advanced PE for Edexcel Heinmann
Websites
Articles
Brigham, D 'An Assessment of Sports Beverages for Athletes' from
