Athletes are dedicated to their sport. They exercise daily, train with professionals, lift weights, engage in team practices, and compete against one another. All this commitment is made in an effort to make the human body work more efficiently. Continuous exercise and training, conditions the muscles to work better alongside the bones. For example, baseball pitchers would want to train the muscles in the arm to throw a blazing fast pitch, long distance runners would work to control the respiratory system in order to finish strong at the end of an extensive race, and football players build on agility and muscular endurance sequentially outrunning the opponent. The current generation of athletes has caused competition in sports to reach unprecedented levels. However, the burning question remains, are athletes consuming the right foods to fulfill their activities? Adequate nutrition is an integral aspect to athletic performance. Athletes that demand a higher performance in their respective sport and training should have a high nutritional value in relation to their activities. It is critical to maintain a balanced, healthy diet at all times in order to achieve maximum performance. A good diet with adequate nutrition such as vitamins, minerals, protein and water in terms of the proper amounts of calories support activities.
Athletes acquire energy from the foods they eat. Food can be further divided into two categories: macronutrients and micronutrients. Macronutrients supply an athlete with direct sources of energy for daily life activities and physical exercise. Macronutrients include proteins, carbohydrates, and fats  . Micronutrients aid in the processes of life, such as digestion and food metabolism. Although they are not able to provide energy, they are essential in generating energy for the human body. Some examples of micronutrients are vitamins and minerals  .
Protein is a macronutrient involved in many chemical processes of life. Proteins are specialized for different organs and species. Proteins are combinations of amino acids that combine in various ways to make muscle, bones, tendons, skin and many other tissues. When proteins are broken down by the body at ingestion, amino acids are formed. There are 20 amino acids which help form human proteins, however only 9 are essential. Meaning 9 out of the 20 proteins are supplied by the food we eat, because the human body is unable to produce them through synthetic processes in the cell. Protein is one of the components in body tissues, necessary for cellular growth and repair, as well as in hormones, enzymes, the immune system, and bodily fluids  . Athletes need protein primarily to repair and rebuild muscle that is broken down during physical exertion. Working out breaks down muscle fibers and the body has to quickly rebuild those fibers for future performances. Through the process of restoration the body synthesizes proteins. The muscle fibers broken down during training will strengthen over time as adequate amounts of protein are ingested to facilitate the growth process  . Protein is the last source of energy used when other macronutrients are available. When the body lacks adequate carbohydrates, the body turns to protein as a source of fuel for physical activity. During extreme physical activity, muscle tissue becomes an energy source because there is an insufficient amount of fat and carbohydrates consumed. Therefore it is necessary to maintain an adequate protein intake everyday, to make up for the protein lost in the muscle tissue during an increase in intensity or length of training  .
Research has shown an amino acid known as creatine, can help enhance athletic performance. Derived from other amino acids, glycine, arginine, and methionine, creatine is stored in the skeletal muscle as creatine phosphate. The job of creatine phosphate is to help facilitate the production of energy. With an increased store of creatine phosphate in the body, the ability to produce energy during high intensity training is improved. This is a result of muscles in the body that have the ability to store a greater amount of creatine than what athletes consume from their diet. Athletes can obtain creatine primarily from meat and fish  .
Carbohydrates are the primary fuel for the exercising muscles and are essential for supporting the training and performance of an athlete. They are the major energy source for anaerobic and aerobic activity. Carbohydrates are broken down into glucose molecules and stored in our skeletal muscles and liver as glycogen. The amount of glycogen stored affects stamina and endurance. After an athlete is done training, glycogen is released from the liver into the bloodstream to restore the glucose levels in the blood, and glucose is transported to cells for energy  . If the blood glucose levels are low, athletes may feel irritable, tired, and lack concentration, interfering with their performance. Glycogen stored in the skeletal muscles provides fuel for the exercising muscles during high and low-intensity activities. There are limited carbohydrate reserves in the body and exercising causes the glycogen stores to become depleted very quickly. During exercise, if muscle cells run out of glycogen, the muscles lack energy and fatigue sets in. Performance suffers accordingly, but will vary depending on the sport and its intensity  . Therefore, daily carbohydrate consumption and training is necessary to maintain glycogen for optimal performance. In order for athletes to obtain enough energy to maximize athletic efforts, carbohydrates also aid in fat metabolism. The presence of carbohydrates is essential in utilizing fat for energy, associating with the old saying, aa‚¬A“fat ‘must burn in a carbohydrate flameaa‚¬?  . Increased fat-burning helps to conserve carbohydrates in the muscle, therefore the stored up amount is used to support athletes in later activities  . In general, endurance athletes use up more carbohydrates than athletes that use carbohydrates for strength and power. This is because endurance athletes are participating in physical activity over a longer period of time, meaning a greater amount of carbohydrates is required by the body to supply it with energy over the duration. On the other hand, athletes involved in strength and power events require fewer amounts of carbohydrates to supply a sudden burst of energy for powerful, but short-lived physical activities  . Adequate intake of carbohydrates will prevent the body from extracting other macronutrients from their desired jobs to become fuel for activity. Ideal sources of carbohydrates include whole-grain cereal, pasta, brown rice, and brown bread products. As part of a healthy diet, athletes should include at least two carbohydrate-rich foods accompanying each meal, and at least one with every snack  .
Prior to competitions, athletes like to load muscles with glycogen to delay fatigue that occurs during endurance events. A diet that contains highly nutritious carbohydrates, covering 55-65% of total calories, is sufficient enough to provide adequate glycogen storages that will help support the athlete over the duration of their performance  .
Fat is the predominant fuel source during prolonged exercise. The body has an unlimited storage capacity for fat, making it the largest reserve of energy in the body. It is integral for many metabolic processes such as energy production, synthesis of vitamin D, cholesterol, hormones, and transporters of lipid soluble vitamins. Fat can be classified into two categories based on its structure: unsaturated and saturated fats. Unsaturated fats are obtained from plant sources. Advantages of unsaturated fats include lowering cholesterol and reducing the risk of heart disease. Saturated fats on the other hand, come from animal sources and cheese. Saturated fats are not recommended in large consumption to athletes, because an excess of this macronutrient will raise cholesterol and/or lipid levels in the blood which can lead to the development of heart-related diseases  . However, fats do hold a place in sports nutrition. Fats are less oxygen-rich, and they can release a greater amount of energy at a greater speed than other nutrients. This can provide an athlete with a concentrated source of energy. Fat is essential for longer and lower intensity, endurance exercise. Another role that fats play in the human body is insulation. Fats assist in insulating and protecting vital organs and parts of the body  . Athletes can obtain fat from food sources such as milk, butter, meat and oils  . Athletes need to keep in mind to carefully monitor the type and the amount of fats they eat.
Vitamins are essential micronutrients athletes need to produce energy. Vitamins mostly come from the food we eat, with the exception of vitamin D. Instead of participating in the metabolic processes of nutrients, vitamins help to regulate the reactions in metabolic processes. They are responsible in facilitating energy release and synthesizing bone and tissue. Absence of a vitamin prevents certain metabolic processes from occurring in the cell, which eventually affects the metabolic balance in the body, as a whole  .
Another micronutrient occurs naturally on earth. It is found in the water, soil, and the plants of Earth. This micronutrient is known as the mineral. There are seven key minerals: calcium, potassium, phosphorous, magnesium, sodium, chloride, and sulphur. Two minerals that are important for athletes are iron and calcium. Iron is a main component in the blood. It is critical for red blood cell formation, function and myoglobin composition. Iron operates in the blood as an oxygen carrier, a key role in sport performance. If iron levels are low in athletes, they can develop fatigue, poor appetite and an increase in resting pulse rate. This occurs because an insufficient supply of oxygen is distributed to parts of the body. Oxygen combines with glucose to form ATP molecules, the main source of energy for the muscles. The greater amount of ATP stored in the muscles, the more powerful they will be when it performs work. Low iron levels in the blood mean that muscles do not receive enough oxygen to support exertion. This results in lactic acid being produced and the athlete endures pain and fatigue in the muscles. However, excess amounts of oxygen in the body help athletes to metabolize lactic acid back into useful energy molecules after exercise. This allows the muscles of athletes to recover faster and be able to carry out physical activity again without having to rest for long periods of time. Iron can be obtained from many food sources, such as cereals, red meats, and bread products  .
When athletes want to develop stronger bones, they need to consume calcium in their diets. Calcium is a micronutrient from the popular dairy food group, comprised of milk, yogurt and cheese. Ninety-nine percent of the calcium in our body is stored in the skeletal system, while the remaining one percent is accumulated in the muscle cells  . When muscles are at work, calcium ions are released to trigger muscle contraction. Calcium ions are released into the sarcoplasm and then they find their way to attach onto the troponin molecules. Without the attachment of troponin molecules and calcium, the interaction of actin and myosin leading to muscle contraction will not occur. Thus, if muscle contractions are not generated, athletes are unable to perform their activity  . Low calcium levels in the body are in relation to developing low bone density. This causes the bones of the body to become more fragile and vulnerable to stress fractures, as the limiting amount of calcium will be used for muscle contraction. Therefore in order for athletes to withstand intense physical activity, an adequate amount of calcium is essential in their meals  .
Finally, athletes need to stay hydrated for optimal performance. The human body consumes energy during physical exercise and creates heat. Bodily temperature would rise drastically causing the body to overheat, if heat was not released. In conjunction with the release of heat, the bodyaa‚¬a„?s sweat glands discharge fluid to the surface of the skin, where it eventually evaporates. This overall process occurs in an effort to cool the body. However, this leaves the body dehydrated  . Water comprises 50-60 percent of the weight of human bodies  . This portion of water in the human body helps to regulate heat and maintain a constant body temperature. Water helps to transport nutrients to cells and extract waste products. Water distributes the heat generated by physical activity throughout the body and enables the body to perspire. Fluids, not just water, are lost when humans perspire, urinate, defecate, and respire. A constant replacement of fluids is necessary for the human body to continue to operate and achieve its optimal performance. Research has shown that when athletes sweat, they lose 1-2% of body weight which is linked to a decrease in blood volume. This process causes the heart to work harder to circulate the blood, resulting in muscle cramps and dizziness  . Athletes establish proper hydration by drinking the right fluids during physical activity. This means drinking fluids properly throughout the day when thirsty, and especially before an activity begins. In the course of a long competition, where fluid is being lost in sweat, sport drinks are good sources of electrolytes. The sodium levels in the drinks are ideal replacements of sodium secreted in sweat. Low sodium levels can affect concentration. In general it is not advised for athletes to drink sport drinks such as Gatorade, on a regular basis or every time they participate in physical activity. These fluids can interfere with the body absorbing the proper nutrients and encourages thirst in the individual  .
The principle that underlies healthy eating and enhancing sports performance is maintaining a balance between food consumption and the amount of energy that is going to be used for work. Since athletes participate often in physical exercise, they will need to absorb more energy in the foods they eat. The following principle is expressed as an energy equation: Energy storage = Energy intake aa‚¬” Energy output. Energy storage represents the amount of energy left in the body after the amount of energy used is reduced from the amount of energy taken in by the body. If athletes absorb insufficient amounts of energy from food sources, optimal performance will not be achieved. Muscles will weaken without nutrients and negative health effects become a concern for athletes  .
Athletes spend many hours training and undergoing physical activity so the body can excel in sports performances. It is important that athletes keep their bodies nourished in order to supply fuel for athletic endeavours. Athletes need to develop a focus on maintaining proper nutrition, so the hours spent during physical activity and rest are not subjected to waste. Good nutritional habits are necessary to achieve optimal physical performance, however it does not mean that we should categorize foods as good or bad. To maintain a healthy lifestyle, athletes should consume foods from various food groups and make better food choices at the same time. Daily food choices should include macronutrients such as protein, carbohydrates, and fat, micronutrients such as vitamins and minerals, and most importantly fluids, such as water. Athletes are better equipped to meet their maximum athletic potential if the right foods are taken in the right amounts to fuel the body. Great athletic accomplishments are determined by great nutrition.