The relationship between food consumption and athletic performance.
Function
Perhaps only an elite athlete would value the subtle improvements in
performance that dietary changes can provide. There is a large body of
evidence showing a relationship between food consumption and athletic
performance. A poor diet will almost certainly have a negative effect
on the performance of even the most casual athlete. A good diet providing
adequate calories, vitamins, minerals, and protein will help provide
the energy required to finish a race or simply enjoy a recreational sport
or activity.
Recommendations
The diet recommended for an athlete differs little in composition from
the diet suggested for any healthy individual. The Food Guide Pyramid
is an excellent guide, however, the amount of each food group needed
will depend on the type of sport, the amount of training and the time
in relation to activity or exercise. Calorie needs vary with the size,
age, sex and physical activity performed by the individual so the number
of servings a person requires will vary.
CARBOHYDRATES:
Complex carbohydrates are a diet staple. They are found in foods such
as pasta, bagels, whole grain breads and rice. They provide energy, fiber,
vitamins, and minerals and are low in fat. Carbohydrate loading (a concerted
diet/training regimen) will increase the body's energy stores of carbohydrate
(called glycogen). It has been shown to improve performance in endurance-type
activities lasting more than 1 hour. The classical method of carbohydrate
loading has been abandoned and replaced by a modified method which is
safer and equally effective at increasing muscle glycogen. The most important
factor influencing glycogen stores is to consume 50 to 60% of the calories
from carbohydrates on a daily basis.
Simple sugars such as soft drinks, jams and jellies, and candy provide
few nutrients but a lot of calories. They may actually decrease performance
when consumed directly before an athletic event as they may cause hypoglycemia.
PROTEIN:
Protein's most important functions in the body are to support growth
and to repair body tissues. Many people feel athletes need a high protein
diet to support muscle growth despite the fact that researchers have
repeatedly proven this false. It is also a myth that a high protein diet
will promote muscle growth. Only strength training and exercise will
promote changes in muscle. Athletes, even body builders, require only
small increases over normal needs in order to support muscle growth.
Athletes easily meet this increased need by simply consuming more total
calories (eating more food). Americans already eat more protein than
they need, almost two-fold, so protein needs for muscle development are
being met before strength training begins. Excess protein is used as
energy and can be stored as body fat. Amino acid supplements and excessively
high intakes of protein are not recommended. They can increase calcium
loss, and put an added burden on the kidneys which are required to filter
the excess nitrogen protein provides.
WATER AND FLUID:
Water is the most important, yet over-looked, nutrient by athletes.
Water and fluids are essential to maintaining good hydration and body
temperature. Sweat losses to keep the body cool can exceed several liters
in a 1-hour period. Adolescents and adults should replace any lost body
weight lost during a exercise with equal amounts of fluids. A good indication
that you have fully rehydrated is to check to see if your urine is clear.
Cool water is the best choice.
Some suggestions for maintaining adequate hydration are:
Drink plenty of water, juice and milk.
Avoid caffeine containing beverages. Caffeine is a diuretic and promotes
fluid loss.
Drink plenty of fluid before, during, and after exercise.
Offer children water frequently during sports activities; they do
not respond to thirst as readily as adults.
ACHIEVING DESIRED WEIGHTS FOR COMPETITIVE PURPOSES:
Changing body weight to improve performance must be done safely and
effectively or it may do more harm than good. Maintaining an unrealistically
low body weight, rapid weight loss, and unnaturally suppressing weight
gain can have negative health effects so it is important to set realistic
body weight goals.
Young athletes attempting to lose weight will benefit from a consultation
with a Registered Dietitian; eating disorders and poor dietary habits
may result from experimentation with diets. The Food Guide Pyramid is
an excellent resource to ensure adequate food intake to meet vitamin
and mineral needs while safely achieving body composition goals.
Make sure that you speak with a health care professional to discuss
a diet appropriate for your sport, age, gender and amount of training.