To determine the proper nutritional need for an athlete, many factors must be considered. The energy demands of an athlete must be individualized since multiple factors are involved, such as age, sex, height, weight, level of activity and intensity of activity. It is also dependent upon if the athlete is at a healthy weight and needs to maintain weight or if weight gain or loss is desired.
There is no one “cookbook recipe” that would apply to all athletes; however, all athletes must incorporate both macronutrients and micronutrients into their diet.
Macronutrients include carbohydrates, fats and protein. The Institute of Medicine recommends the following breakdown of macronutrients in the daily diet: carbohydrates 45 percent to 65 percent of total energy intake, fats 20 percent to 35 percent of total energy intake, and proteins 10 percent to 35 percent of total energy intake. The range is to make appropriate adjustments based on the goal of the nutrition plan and the level of activity of the individual athlete. For instance, if an athlete is geared toward strength training, then you want to increase the percentage of protein in the diet and decrease the percentage of carbohydrates.
Micronutrients include the vitamins and minerals that are important in your diet. Their role is to help the body utilize the macronutrients. Vitamins that are necessary in your diet include A, B complex, C, D, E and K. Minerals include calcium, phosphorous, potassium, iron, zinc, selenium, magnesium, sodium, copper, chromium, iodine and fluoride. Micronutrients are obtained from the diet, and the majority of them are adequate in an average diet with the exception of iron and calcium ,which are often supplemented.
Studies have shown that maintaining adequate fluid balance optimizes athletic performance. The minimum requirement for non-active individuals is 3.0 liters per day for males and 2.2 liters per day for females (age 19-35). Thirst is a poor indicator of fluid status. By the time an athlete becomes thirsty, they are dehydrated. Athletes should drink 8- to 16-ounces one hour before an activity, and 4- to 8-ounces every 15- to 20-minutes during an activity. After exercise, drink enough to return the body to its pre-exercise weight. Water is adequate for an activity that lasts up to an hour, while exercise of a longer duration benefits from sports drinks.
Although there are various recommendations for a pre-game meal, there is no scientific data to support one over the other. However, there are some things to consider with a pre-game meal. The point of the meal is to provide fuel and fluids for competition. Timing of the meal is very athlete-dependent, but generally averages two- to three-hours prior to competition. The meal must be well tolerated and well liked, typically lower in fat since that may delay gastric emptying. Notably, protein seems to be beneficial prior to a strength-training session.
Carbohydrates consumed one- to two-hours after a game/event will replace glycogen stores and refuel muscles; and protein will help muscle recovery. Protein is also beneficial after a strength-training session.