Eating for Peak Performance
Susan M. Kleiner, PhD, RD
Nutrition plays a critical role in athletic
performance, but many active people do not eat a diet that helps them do
their best. Without a basic understanding of nutrition, popping a pill seems
easier than planning a menu. In reality, there is no pill, potion, or powder
that can enhance your performance like the right foods and fluids.
The Energy Diet
To have enough energy you need to consume enough
energy. Getting adequate calories is one of the keys to an ergogenic, or
performance- enhancing, diet. With too few calories you will feel tired and
weak, and you will be more prone to injuries.
The ergogenic diet is based on the US Department of
Agriculture's widely published food guide pyramid, which includes five basic
groups: grains, fruits, vegetables, dairy foods, and protein-rich foods.
Sugars and fats provide extra calories after the needs for foods from the
other groups have been met.
By eating adequate calories from a variety of
foods, you will satisfy your need for macronutrients (carbohydrate, protein,
fat) and micronutrients (vitamins, minerals).
Carbohydrates. A high-carbohydrate diet
increases stores of glycogen, the energy for muscles, and improves overall
athletic performance. The bulk of the day's calories--60% to 70%--should
come from carbohydrates such as bread, cereal, grains, pasta, vegetables,
Different carbohydrate foods can affect your energy
level in different ways. Digestion rates are expressed as a "glycemic
index." Foods with a high glycemic index release energy into the bloodstream
rapidly, while foods with a moderate or low glycemic index release their
energy more slowly. However, beware of the old idea that simple sugars are
always digested rapidly and cause wide swings in blood sugar, and that all
complex carbohydrates like bread are digested more slowly and don't cause
blood sugar fluctuations. This turned out to be wrong, as the table shows.
If you exercise for longer than an hour, you can
begin to deplete your muscles of glycogen. By consuming 30 to 75 grams per
hour of high-glycemic-index carbohydrate in liquid or solid form when you
exercise, you can minimize this effect.
After a long workout or competition, your depleted
muscle glycogen stores must be replenished, especially if you will be
exercising again within the next 8 hours. Eat at least 50 grams of high-glycemic-index
carbohydrate just after exercise, and consume a total of at least 100 grams
of high-glycemic-index carbohydrate in the first 4 hours afterward.
Moderate-glycemic-index foods may be added for the
next 18 to 20 hours, with a goal of consuming at least 600 grams of
carbohydrate during the 24 hours after an intense workout or competition.
Fat. Fat is definitely an important energy
source, particularly for athletes involved in prolonged, low-intensity
activity. (For high-intensity, short-term activity, carbohydrate is the
primary fuel source.) About 20% of the calories in a performance-enhancing
diet should come from fat (1), most of it unsaturated fat like vegetable and
Protein. Protein plays a minor role in
energy production, contributing only 5% to 10% of the energy used during
prolonged exercise. Although the current recommended dietary allowance for
protein is about 0.4 grams per pound of body weight per day, most active
people need slightly more. And athletes involved in heavy resistance
exercise or prolonged endurance events may require 0.7 to 0.9 grams per
pound per day. Even this amount is relatively easy to eat, since 3 ounces of
fish or chicken, 1 1/2 cups of tofu, or 1 1/2 cups of garbanzo beans contain
20 to 24 grams of protein.
Vitamins and minerals. They don't contribute
energy themselves, but vitamins and minerals are integral to food metabolism
and energy production. Iron and calcium are the minerals most commonly
deficient in athletes, and strict vegetarians may be deficient in vitamin
B12. By consuming adequate calories and following the food guide pyramid
plan, your needs for all the important micronutrients can be met.
Water is the ultimate ergogenic aid--but because
the body has a poor thirst mechanism, you must drink before you feel
thirsty. Once you are thirsty you are already slightly dehydrated, and your
performance will be diminished. To stay well hydrated, you need to drink
about a quart of caffeine-free, nonalcoholic fluids for every 1,000 calories
of food you eat, assuming you maintain your weight.
To ensure that you are well hydrated before you
exercise, drink 2 cups of water or sports drink 2 hours before hand. To
avoid dehydration during exercise, begin drinking early and at regular
intervals. For exercise lasting an hour or less, 4 to 6 ounces of cool water
every 15 to 20 minutes provides optimal fluid replacement.
During exercise that lasts longer than 60 minutes,
carbohydrate-electrolyte beverages containing 5% to 8% carbohydrate should
be drunk at the same rate to replace fluid and spare muscle glycogen. Also,
consuming sports drinks during intense activities such as soccer or
basketball may enhance performance. After exercise, replace every pound lost
during exercise with at least 2 cups of fluid.
The Ergogenic Future
The search for energy-giving food substances is
widening. Alongside old standards like caffeine and herbal stimulants stand
newly researched substances like capsaicin, the active ingredient in hot red
chili peppers. One study showed that runners who ate a breakfast laced with
10 grams (about 1/3 of an ounce) of dried hot red pepper powder burned
carbohydrates faster, both at rest and during exercise (2). These results
are preliminary and tentative, but they raise the question whether designer
ergogenic foods may be in our future. Until then, you'll find the staples of
your ergogenic diet in the food aisles of your local supermarket.
This article was provided by Mark Occhipinti, President of AFPA. AFPA is
dedicated in providing fitness professionals with an affordable, practical,
and functional experience in health and fitness education. Visit their web
site at http://www.afpafitness.com
for up-to-the-minute information and in-depth details about AFPA
conferences, seminars, certification programs and CEC's.