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Dr. Gillaspy has taught health science at University of Phoenix and Ashford University and has a degree from Palmer College of Chiropractic.
Professional athletes enhance their performance through proper nutrition, but you don't have to be a pro to benefit from good nutrition. Whether you're a serious competitor or a weekend warrior, your diet provides you with the calories you need for energy, the proteins that support your muscle mass, and the vitamins and minerals your body needs to perform at its best. In this lesson, we will evaluate how and why nutrient and calorie needs vary from one athlete to the next.
If you're a casual athlete who enjoys joining in with friends in a laid-back game of basketball or volleyball, then your body might only burn about 100 extra calories due to your activity. This is a small need when compared to a competitive endurance athlete, like a marathon runner or a bicycle rider, who can require 2,000 to 6,000 additional calories or more to sustain their performance.
Food calories supply the energy all athletes need, and we see that energy needs vary depending on intensity, duration and frequency of the exercise. In general, the higher these factors are, the more energy the athlete needs. But, there is another variable that will determine the energy needs of an athlete, and that is body weight. Body weight is a factor because more energy is required to move a heavier object than a lighter one. Therefore, if two men, one weighing 200 pounds and one weighing 150 pounds, line up at the starting line of a 5K race, the 200-pounder will require more energy to get to the finish line than the 150-pounder.
I mentioned that calories come from foods, but there are actually only three calorie-containing or energy-yielding nutrients, namely carbohydrates, proteins and fats. The right mix of these nutrients can be as important to the athlete's performance as the total calorie count. The majority of calories in an athlete's diet should come from carbohydrates. This is because carbs get digested into the simple sugar glucose.
Glucose is the easiest molecule for your body to convert to adenosine triphosphate (ATP), which is the form of energy your body uses. Eating sufficient amounts of carbohydrates also allows athletes to maintain levels of glycogen, or stored glucose, in their muscles, making more glucose available during physical activity. To maximize this storage, it's recommended that an actively training athlete's diet should consist of approximately six to ten grams of carbohydrates per kilogram of body weight.
We all know the body stores fat. Even a slender athlete carries enough body fat to provide energy for intense endurance sports, but this doesn't mean an athlete should avoid eating fat in his or her diet. In fact, a low-fat diet may reduce athletic performance. Therefore, athletes should get between 20 to 35% of calories from fats. This is the same recommendation for the general population, so we see that exercise does not strongly affect the amount of dietary fat that a person needs to consume.
What about protein? Well, your body doesn't like to burn up proteins for energy because this nutrient is so important for other functions in your body. However, when there is something extreme going on, like a competition that requires a high level of endurance or strength, the building blocks of proteins can be converted into ATP. Dietary protein also helps the athlete's body by maintaining and repairing muscle. We know that the daily recommended dietary allowance for the general population is 0.8 grams of protein per kilogram of body weight. Athletes may require extra protein, and we see that competitive athletes may require 1.2 to 1.7 grams of protein per kilogram of body weight.
Calorie-containing nutrients alone are not always enough to support an athlete during training. Athletes also require vitamins and minerals to optimize their performance. Due to the added demands placed on the body during training, an athlete's body uses more vitamins and minerals than a casual exerciser.
We also see that certain minerals can be lost during training, which is the case with the mineral sodium, which is lost in sweat. Sweating is necessary during exercise because it helps cool the body, but if you do not replace the right proportion of water and sodium after a prolonged period of sweating you could end up with hyponatremia, which is a condition in which blood sodium levels are abnormally low.
If an athlete only drinks water to replenish lost fluids, then the water to sodium balance in the blood will be thrown off, resulting in symptoms such as disorientation, seizures, a coma and even death. Sports drinks that contain electrolytes can supply an athlete's body with sodium during times of exercise. Sufficient levels of vitamins and minerals help the body produce energy. For example, the B vitamins help run the reactions that convert food molecules into ATP, so a deficiency in B vitamins could decrease energy production during athletic competition.
Every human body is subjected to damage caused by free radicals, which are highly reactive molecules that bounce around inside the body like marbles in a pinball machine, causing damage to cells and anything else they run into. However, exercising increases the production of free radicals, so athletes may need more of the vitamins and minerals that fight free radicals: vitamin C, vitamin E, beta-carotene and selenium.
Athletes may also require additional amounts of iron, which is a mineral needed to make the oxygen-carrying protein, hemoglobin, found in red blood cells. Because exercise stimulates the need for more red blood cells, there is more demand for hemoglobin production. Without sufficient iron to make hemoglobin, an athlete's muscles might not get an adequate supply of oxygen during physical activity.
Let's review. Energy needs vary depending on intensity, duration and frequency of the exercise an athlete is engaged in, as well as the athlete's body weight. Calories from foods supply the energy all athletes need, with the three energy-yielding nutrients being carbohydrates, proteins and fats.
An actively training athlete's diet should consist of approximately six to ten grams of carbohydrates per kilogram of body weight, making carbohydrates the majority of calories in an athlete's diet. This is because carbs get digested into the simple sugar glucose that is easily converted to adenosine triphosphate (ATP), which is the form of energy your body uses.
Athletes should take in the same amount of dietary fat as the rest of the population, meaning athletes should get between 20 to 35% of calories from fats. But athletes may require extra protein, and we see that competitive athletes may require 1.2 to 1.7 grams of protein per kilogram of body weight.
Athletes also require vitamins and minerals to optimize their performance. Sodium is lost in sweat. If an athlete doesn't replace the right proportion of water and sodium after a prolonged period of sweating, it could lead to hyponatremia, which is a condition in which blood sodium levels are abnormally low. This causes symptoms such as disorientation, seizures, a coma and even death.
A deficiency in B vitamins could decrease energy production because the B vitamins help run the reactions that convert food molecules into ATP. Because exercise increases free radicals, which are highly reactive molecules that damage cells, athletes may need more of the vitamins and minerals that fight free radicals: vitamin C, vitamin E, beta-carotene and selenium. And, because exercise stimulates the need for more red blood cells, athletes may require more iron, which is a mineral needed to make the oxygen-carrying protein, hemoglobin, found in red blood cells.
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Back To CourseHealth and Wellness
11 chapters | 103 lessons