The effect of exercise and diet on an athlete.
It’s important to understand that athletes need to think about weight control during certain sports, such as a runner; who would use less energy if body weight was reduced and on the other extreme wrestlers and boxers who have a weight class may move up and down in class depending on individual weight. Walberg-Rankin, 2000.
Nutrition can comprise of several factors such as energy, nutrition and appropriate fluid needed for an athlete to perform during training or competition. If the athlete has no sound nutritional advise for his/her sport, recovery will be insufficient, this will result in an increase of fatigue and illness may continue. It’s important to understand that athletes use more energy for there specific sport will need to consume a lot more nutrients, and it’s safe to say that for some sporting events adequate nutrition consumption is hard, sports like golf, swimming and running which are a small sample of sports. Ray and Fowler, 2004 support this and explain in there article that the American College of Sports Medicine (ACSM) and American Dietetic Association (ADA) believe that physical activity or athletic performance and recovery are enhanced by optimal nutrition. The article also explains that the main nutrients, Carbohydrates, Protein and Fat are important for the ideal athletic performance. Ray and Fowler, 2004 suggest that many athletes rely on a sports nutritionist who will design a food plan and strategies to maintain, lose or gain weight.
Exercise is an important part of weight control, the idea of exercise for weight control is different for each individual dependant on individual goals. When looking at exercise for weight control we should decide if the idea is to improve or maintain weight for the specific sport. The American College of Sport Medicine recommend, thirty minutes or more of moderate physical activity, three to five days a week. These activities could include walking gardening and dancing, this can also come from gym based exercise such as jogging or rowing. Sharkey, 2002. Miller, 2001 explains that exercise should be part of any obesity intervention and a meta-analysis has shown that the average weekly bodyweight loss through exercise participation can be only 0.2 – 0.04kg. Stiegler & Cunliffe, 2006 support the role exercise has on weight control, the subject would need to take part in a considerable amount of physical activity and maintain the same energy intake throughout the training period then a decrease in body fat would be apparent.
There are a number benefits and strategies that nutrition has over weight control a study by Miller, 2001 looks into the a high-protein/low-carbohydrate diets which are claimed to be the effective for reducing bodyweight. E.g. the Atkins Diet. The Atkins diet was introduced in the 1960’s and early 1970’s, and has become increasingly popular in the last ten years. Although research show’s that there are a lot of factors that are against the high-protein/low carbohydrate diet such as nausea and fatigue caused by low carbohydrate or glycogen stores. Miller, 2001 also explains that health risk factors such as a risk of heart disease, high blood pressure and osteoporosis. But there are no scientific data to support the claims that this diet can reduce body weight and as motioned above persons on these types of diets are also at the greatest risk for metabolic adverse effects.
The food pyramid is a tool used to support the idea of a diet based on carbohydrate rich foods and shows each amount using a six section pyramid structure. The pyramid is designed to provide the individual with an image of the food they need to eat for their nutritional needs. Williams, 2005. Body weight goals for athletes should be based on an individual’s current body composition and the amount of time until the beginning of the new season, their weight when they started and sport-specific rules such as weight class. Its important for an athlete not to exceed 1-2 % of body weight per week because, Walberg-Rankin, 2000 explain that this can have an adverse affect on the athlete that could hinder performance. Other strategies looking at weight loss could consist of reading food labels to determine how mush is being consumed be serving, limit the fatty add-ons such as sour cream and mayonnaise. Encourage individuals to consume at least 60% of their food from carbohydrates it was suggest at least 5g of carbohydrates per kg of body weight. Walberg-Rankin, 2000
It has been agreed that a combination of both diet and exercise can have a positive influence on weight control. Obesity is a fast growing around the world due to a number of contributing factors the main factor is environmental influences such as a hectic lifestyle which contributes to the problem. Long working hours with limited time to exercise, inadequately nutritious fast and easy meals such as, microwaveable and takeaways. Volek, et al 2005. . For an athlete to decrease body weight they must have a calorie defect Jakicic and Otto, 2006 explain that excess bodyweight is a result of an imbalance in energy. This is where energy is decreased over the amount of energy being consumed, which will result in weight loss.
Research on metabolism suggest, metabolism as energy, and it’s the metabolic rate that suggests how quickly this energy is utilized. Metabolism is the physical and chemical changes within the body. The metabolism process is a combination of bone and muscle growth, the formation of compounds such as hormones and enzymes, and how food and energy are transformed. To understand how this helps weight control within our athlete we need to understand the metabolism is broken down into two processes, anabolism and catabolism. Williams, 2005 suggest that anabolism is a type of construction process, so if a weight lifter was training anabolism will increase muscle mass within the lifter. Catabolism is the second process, this is the process that breaks down the individual body compound to it’s simplest form, so that it can be used efficiently, catabolism releases energy and some of that energy is used to support anabolism.
Basal Metabolic Rate (BMR) is the energy required for the different processes both cellular and tissue, resting state or sleeping is the lowest form of energy. The test for BMR is usually in a lab, by testing an individuals oxygen consumption and the amount of carbon dioxide produced, you will get a better understand of the amount of energy that needs to be consumed within the body, during this type of experiment subjects will be encouraged to fast for at least 12 hours prior to testing. Williams, 2005 Another metabolism process is Resting Metabolic Rate (RMR) this is said to be used interchangeably with BMR but Williams, 2005 explains that it is slightly higher and looks at the energy released from consuming food and the effects of physical activity. So can the two be used interchangeably, The National Research Council explain that the two can be less than 10 percent different, which is reasonable justification. BMR or RMR/REE can help weight control in athletes by providing information about the correct energy or calories to consume, it’s important to understand that fat has a lower metabolic level than muscle tissue so therefore more energy will be needed for an athlete with high muscle mass, this doesn’t take into account the energy used during exercise.
The body has ways to regulate its self with weight control, but it’s not always as easy as that; energy intake is said to be controlled by the central nervous system. So through the CNS the body will control these energy cravings there are a number of stimuli that Williams, 2005 suggest; Senses such as sight, sound and smell, Stomach fullness, this looks at the mechanical stretch reflectors in the stomach, Nutrition level, looking at the blood and how the liver and hypothalamus monitor the levels of nutrients within it, Body temperature and hormones. These stimuli are physiological regulators for food intake, but referring back to metabolism, it’s suggested that although exercise increase the amount of energy expenditure, most energy is experienced during rest because of the short time taking part in physical activities. So does this suggest that if some athletes increases the amount of activity they do, they will speed up metabolism thus feeling more hungry, so as food is consumed it will utilized more rapidly, but after exercise has finished and the athlete is at a state of rest metabolism will slow down so fewer calories will need to be consumed.
The human body has a number physiological systems, which are also referred to as a feedback control. Williams, 2005 uses an example of temperature control as a good form of feedback, this will be both long and short term use, where as the body storing carbs, protein or fat are checked on a short term basis. An example of a long term basis would be the Set-Point Theory for weight control. This theory explains that our bodies are regulated to a certain weight, or set point. Williams again uses temperature as an example the body is regulated at a temperature of 98.6 degrees F and if this changes, in anyway, our body’s will self regulate by adjusting the metabolic conditions.
Good weight control is a combination of exercise and diet, and this is important in all sports. Some widely researched sports such as football which is a game of speed, strength, skill and Stamina and all these attribution require a certain amount of nutrition. Carbohydrates help the working muscles from fatigue by replenishing the glycogen stores. Examples would be rice, bread, pasta potatoes and vegetables. Strength and muscle mass would involve a high energy diet and carbohydrates are the key source of this, protein is important to repair muscles but its suggested by Ray and Fowler, 2004 that it’s not as important as carbohydrates. Footballers are encouraged to snack in between meals with healthy options, skipping meals are not a good idea, snacks should be taken to training, these snacks should be high carbohydrates such as fruit and sports drinks. It’s important for the body to get use to a routine, so that the body can digest and absorb the nutrients quickly, footballers will be encouraged to drink water at every opportunity, to stay hydrated. During competition players will be encouraged to drink sports drinks (Gatorade, Lucozade) that have the benefits of tasting good, contain electrolytes are important because they are what your cells and may prevent cramping.
Golf professionals can spend anything up to eight hours a day on a golf course. Training is important part of the game, sessions may include flexibility, strength and endurance, all these area’s will help reduce the risk of injury. Ray and Fowler, 2004 explain that golf is a game of skill and golfers today are now fitter then before, it’s explained that a mixture of carbohydrates, protein and fat are within the optimal diet. Golfers may not consume food for up to five to six hours so its important for them like footballers to carry food with them during events.
Swimming is another sport that involves appropriate nutrition, it’s important to understand that as a swimming professional training may consist of six to twelve sessions per week lasting around six hours a day. As well as the pool training, sessions such as strength and endurance sessions will be needed for improving bigger stronger muscles and to prevent the possibility of a plateau, which may result if training is consistently the same. Swimmers should have a high energy diet which will consist of carbohydrates again snacking is important to keep refueling the body with energy. This will prevent fatigue during training and competition, poor performance, and loss of body weight. Ray and Fowler, 2004 also explain that during the off seasons swimmers will decrease their energy intake to reduce the risk of weight gain and fluid intake is important during this sport because it isn’t easy to asses if a athlete sweating because the athlete will be in a pool for most of the training.
It’s important for athletes to maximize their carbohydrate intake to improve performance but Clarke, 2003 suggests that protein and fat are just as essential within the diet. Depending on the sport athletes will have a better idea of weight control and nutrition if they are given the right information. If an athlete is using the food guide pyramid for optimal nutrition wholesome breads, grains and cereals would be at the base of the pyramid as well as foods like fruit, vegetables and dried beans, which are a higher carbohydrate. Clarke, 2003 explains that sugary carbohydrates will be at the top of the pyramid and should be limited used as a treat. From the literature researched it seems that the recommendations are based on evidence, that support the intake of high Carbohydrates and this also suggests that exercise capacity and performance during a single exercise session will be enhanced by this increase. Although not all present literature support these findings like Dr Akins Miller, 2001. Burke et al, 2001 suggests that more research should be carried out to make this hypothesis stronger. So is a combination of exercise and diet the best approach, research would agree but it seems to be a trials error process. Each athlete is individual and there are guidelines that can be followed to encourage optimal nutrition and exercise. The important thing is to monitor the amount of training being completed and the intensity compared to the amount of energy being consumed. A combination of using the food guide pyramid when selecting choices as said previously mentioned, so that energy is at an optimal level prior to the event or training. Then after the session athletes should consume food to replenish there low energy stores, once stores are full, foods with low energy should be consumed this may help weight control.
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