The relationship between nutrition and athletic performance is as certain as the connection between physical training and athletic success. The physical demands of all sports necessitate the consumption of healthy foods, with the correct proportion of carbohydrates, proteins, and fats. The types of foods consumed must also contain optimal amounts of vitamins and minerals, all supported by appropriate and consistent hydration levels in the body.
Athletic performance is an expression that is distinct from many of the broader sports science concepts, such as health, fitness, or longevity. Athletic performance describes the efforts made by an athlete to attain specific performance objectives over a period of time. The natural talent or fitness of the athlete will impact the level of performance; all athletes ultimately measure performance by their own standards. Performance is usually regarded as an aggregation of individual results, such as performance over a month, or a season of competition, as opposed to a single or isolated activity. Athletic performance includes not only the assessment of a particular result, but also the concept of recovery; how quickly an athlete can return to the regular training or routine is an important performance factor, as recovery will dictate how the athlete is able to prepare for the next event. Nutrition places a vital role in the improvement of every aspect of performance.
There is no single wonder food or miracle supplement that will guarantee perfect nutrition for an athlete. Science has determined that while there are many ways to nutritionally enhance a diet that is deficient in respect of one or more components, the best approach for athletes and non-athletes alike is to consume a traditional balanced diet, variations of which have been promoted by most governments in the world for over 40 years. There is also strong scientific support for the proposition that subject to modification of caloric intake, due to the energy requirements of sport, the type of diet that provides nutritional value to athletes is very similar to that consumed by the healthy non-athlete.
The balanced diet is usually expressed in one of two ways: as a ratio of the carbohydrate, protein, and fat food groups, or as a food pyramid, where the recommended daily consumption of different kinds of food within the three food groups is defined by portions or quantities. The Canada Food Guide and the formulation named MyPyramid, developed and published by the United States Department of Agriculture (USDA), are two examples. In each recommendation, daily amounts of whole grains, dairy, vegetables, fruits, fish, and meat products are specified, as are suggested methods for cooking and food preparation that will maximize the nutritional value of each food.
It is a central premise of the balanced diet, whether viewed from the apportionment of carbohydrates, proteins, and fats, or by food type and portion, that if the right kinds of foods are consumed, the person will invariably obtain the other crucial nutritional benefits, including the necessary amounts of vitamins, minerals, fiber, and fluids. Carbohydrates such as whole grains, fruits, and vegetables are all excellent vitamin and mineral sources; examples are whole grains, which provide both the vitamin B complex and dietary fiber to aid in digestion, and citrus fruits, all of which are rich in vitamin C.
The development of a specific nutritional plan for an elite-level athlete will represent variations, as opposed to any wholesale changes, to basic nutritional approaches. A common belief among strength athletes, such as weightlifters or those seeking to build muscle, is that their diet must reflect their training through a greater consumption of protein, essential to muscle building and repair, through both foods and dietary supplements. While in short-term situations an athlete might increase protein to assist in a weight program, as a general proposition these athletes require only minimally greater amounts of protein on a daily basis to support their training levels than do other athletes.
Some athletes share the same misconception concerning the fat component of the balanced diet; fats must be reduced, in the belief that the body will be leaner. This approach overlooks that fats are themselves an excellent energy source for the body, released from their storage in the adipose tissues as fatty acids, which are utilized by the cells to produce energy, and glycerol, which is processed by the liver into glycogen. As importantly, when athletes seek to reduce the quantity of fats from that suggested in a balanced diet, they potentially impair the ability of the body to absorb fat-soluble vitamins, including vitamin D, critical to the ability of the body to use calcium in bone construction and repair.
The one class of athlete who may require a more significant deviation from the patterns of the healthy diet is the young athlete, whose body will be experiencing normal growth increases and be subject to the demands of athletic activity. The nutritionally sound diet for this athlete will often require both greater quantities of each food group, as well as careful attention to the levels of minerals such as calcium and magnesium, which are essential to the growth of the musculoskeletal system.