Questions Most Frequently Asked About Sports Nutrition
What diet is best for athletes?
It's important that an athlete's diet provides the right amount of
energy, the 50-plus nutrients the body needs and adequate water. No
single food or supplement can do this. A variety of foods are needed
every day. But, just as there is more than one way to achieve a goal,
there is more than one way to follow a nutritious diet.
Do the nutritional needs of athletes differ
from non-athletes?
Competitive athletes, sedentary individuals and people who exercise
for health and fitness all need the same nutrients. However, because
of the intensity of their sport or training program, some athletes have
higher calorie and fluid requirements. Eating a variety of foods to
meet increased calorie needs helps to ensure that the athlete's diet
contains appropriate amounts of carbohydrate, protein, vitamins and
minerals.
Are there certain dietary guidelines athletes
should follow?
Health and nutrition professionals recommend that 55-60% of the calories
in our diet come from carbohydrate, no more than 30% from fat and the
remaining 10-15% from protein. While the exact percentages may vary
slightly for some athletes based on their sport or training program,
these guidelines will promote health and serve as the basis for a diet
that will maximize performance.
How many calories do I need a day?
This depends on your age, body size, sport and training program. For
example, a 250-pound weight lifter needs more calories than a 98-pound
gymnast. Exercise or training may increase calorie needs by as much
as 1,000 to 1,500 calories a day. The best way to determine if you're
getting too few or too many calories is to monitor your weight. Keeping
within your ideal competitive weight range means that you are getting
the right amount of calories.
Which is better for replacing fluids-water or
sports drinks?
Depending on how muscular you are, 55-70% of your body weight is water.
Being "hydrated" means maintaining your body's fluid level. When you
sweat, you lose water which must be replaced if you want to pet-form
your best. You need to drink fluids before, during and after all workouts
and events.
Whether you drink water or a sports drink is a matter of choice. However,
if your workout or event lasts for more than 90 minutes, you may benefit
from the carbohydrates provided by sports drinks. A sports drink that
contains 15-18 grams of carbohydrate in every 8 ounces of fluid should
be used. Drinks with a higher carbohydrate content will delay the absorption
of water and may cause dehydration, cramps, nausea or diarrhea. There
are a variety of sports drinks on the market. Be sure to experiment
with sports drinks during practice instead of trying them for the first
time the day of an event.
What are electrolytes?
Electrolytes are nutrients that affect fluid balance in the body and
are necessary for our nerves and muscles to function. Sodium and potassium
are the two electrolytes most often added to sports drinks. Generally,
electrolyte replacement is not needed during short bursts of exercise
since sweat is approximately 99% water and less than 1% electrolytes.
Water, in combination with a well- balanced diet, will restore normal
fluid and electrolyte levels in the body. However, replacing electrolytes
may be beneficial during continuous activity of longer than 2 hours,
especially in a hot environment.
What do muscles use for energy during exercise?
Most activities use a combination of fat and carbohydrate as energy
sources. How hard and how long you work out, your level of fitness and
your diet will affect the type of fuel your body uses. For short-term,
high-intensity activities like sprinting, athletes rely mostly on carbohydrate
for energy. During low-intensity exercises like walking, the body uses
more fat for energy.
What are carbohydrates?
Carbohydrates are sugars and starches found in foods like breads,
cereals, fruits, vegetables, pasta, milk, honey, syrups and table sugar.
Carbohydrates are the preferred source of energy for your body. Regardless
of origin, your body breaks down carbohydrates into glucose that your
blood carries to cells to be used for energy. Carbohydrates provide
4 calories per gram, while fat provides 9 calories per gram. Your body
cannot differentiate between glucose that comes from starches or sugars.
Glucose from either source provides energy for working muscles.
Is it true that athletes should eat a lot of
carbohydrates?
When you are training or competing, your muscles need energy to perform.
One source of energy for working muscles is glycogen which is made from
carbohydrates and stored in your muscles. Every time you work out, you
use some of your glycogen. If you don't consume enough carbohydrates,
your glycogen stores become depleted, which can result in fatigue. Both
sugars and starches are effective in replenishing glycogen stores.
When and what should I eat before I compete?
Performance depends largely on the foods consumed during the days
and weeks leading up to an event. If you regularly eat a varied, carbohydrate-rich
diet you are in good standing and probably have ample glycogen stores
to fuel activity. The purpose of the pre-competition meal is to prevent
hunger and to provide the water and additional energy the athlete will
need during competition. Most athletes eat 2 to 4 hours before their
event. However, some athletes perform their best if they eat a small
amount 30 minutes before competing, while others eat nothing for 6 hours
beforehand. For many athletes, carbohydrate-rich foods serve as the
basis of the meal. However, there is no magic pre-event diet. Simply
choose foods and beverages that you enjoy and that don't bother your
stomach. Experiment during the weeks before an event to see which foods
work best for you.
Will eating sugary foods before an event hurt
my performance?
In the past, athletes were warned that eating sugary foods before
exercise could hurt performance by causing a drop in blood glucose levels.
Recent studies, however, have shown that consuming sugar up to 30 minutes
before an event does not diminish performance. In fact, evidence suggests
that a sugar-containing pre-competition beverage or snack may improve
performance during endurance workouts and events.
What is carbohydrate loading?
Carbohydrate loading is a technique used to increase the amount of
glycogen in muscles. For five to seven days before an event, the athlete
eats 10-12 grams of carbohydrate per kilogram body weight and gradually
reduces the intensity of the workouts. (To find out how much you weigh
in kilograms, simply divide your weight in pounds by 2.2.) The day before
the event, the athlete rests and eats the same high-carbohydrate diet.
Although carbohydrate loading may be beneficial for athletes participating
in endurance sports which require 90 minutes or more of non-stop effort,
most athletes needn't worry about carbohydrate loading. Simply eating
a diet that derives more than half of its calories from carbohydrates
will do.
As an athlete, do I need to take extra vitamins
and minerals?
Athletes need to eat about 1,800 calories a day to get the vitamins
and minerals they need for good health and optimal performance. Since
most athletes eat more than this amount, vitamin and mineral supplements
are needed only in special situations. Athletes who follow vegetarian
diets or who avoid an entire group of foods (for example, never drink
milk) may need a supplement to make up for the vitamins and minerals
not being supplied by food. A multivitamin-mineral pill that supplies
100% of the Recommended Dietary Allowance (RDA) will provide the nutrients
needed. An athlete who frequently cuts back on calories, especially
below the 1,800 calorie level, is not only at risk for inadequate vitamin
and mineral intake, but also may not be getting enough carbohydrate.
Since vitamins and minerals do not provide energy, they cannot replace
the energy provided by carbohydrates.
Will extra protein help build muscle mass?
Many athletes, especially those on strength-training programs or who
participate in power sports, are told that eating a ton of protein or
taking protein supplements will help them gain muscle weight. However,
the true secret to building muscle is training hard and consuming enough
calories. While some extra protein is needed to build muscle, most American
diets provide more than enough protein. Between 1.0 and 1.5 grams of
protein per kilogram body weight per day is sufficient if your calorie
intake is adequate and you're eating a variety of foods. For a 150-pound
athlete, that represents 68-102 grams of protein a day.
Why is iron so important?
Hemoglobin, which contains iron, is the part of red blood cells that
carries oxygen from the lungs to all parts of the body, including muscles.
Since your muscles need oxygen to produce energy, if you have low iron
levels in your blood, you may tire quickly. Symptoms of iron deficiency
include fatigue, irritability, dizziness, headaches and lack of appetite.
Many times, however; there are no symptoms at all. A blood test is the
best way to find out if your iron level is low. It is recommended that
athletes have their hemoglobin levels checked once a year.
The RDA for iron is 15 milligrams a day for women and 10 milligrams
a day for men. Red meat is the richest source of iron, but fish and
poultry also are good sources. Fortified breakfast cereals, beans and
green leafy vegetables also contain iron. Our bodies absorb the iron
found in animal products best.
Should I take an iron supplement?
Taking iron supplements will not improve performance unless an athlete
is truly iron deficient. Too much iron can cause constipation, diarrhea,
nausea and may interfere with the absorption of other nutrients such
as copper and zinc. Therefore, iron supplements should not be taken
without proper medical supervision.
Why is calcium so important?
Calcium is needed for- strong bones and proper muscle function. Dairy
foods are the best source of calcium. However, studies show that many
female athletes who are trying to lose weight cut back on dairy products.
Female athletes who don't get enough calcium may be at risk for stress
fractures and, when they're older, osteoporosis. Young women between
the ages of 11 and 24 need about 1,200 milligrams of calcium a day.
After age 25, the recommended intake is 800 milligrams. Low-fat dairy
products are a rich source of calcium and also are low in fat and calories.