Nutrition
& Soccer Performance
You wouldn't put low octane gasoline in a race car,
would you? Yet, even today, with all the research on nutrition and athletic
performance, athletes still fail to realize the connection between the food they
eat and their ability to compete in sports. The time for a reminder is now.
Proteins, fats and carbohydrates are the main
components of your diet. Protein supplies amino acids for many processes in the
body, but supplies little energy for exercise. Despite all the bad press, fat is
a necessary ingredient. Fat insulates nerves, carries substances in the blood,
packs organs and serves as a warehouse for energy, some of which is used to play
soccer. Carbohydrate is the main source of energy in your diet. How much
carbohydrate you eat will directly affect your ability to run and is the subject
of this article.
Carbohydrate is found in many foods like vegetables,
fruits, breads, grains, pasta, and dairy products. When eaten, carbohydrates are
broken down into glucose and stored in your liver and muscles as a string of
glucose molecules called glycogen. If your ability to run far and fast is
related to how much gas you have in your tank (glycogen in your muscles), then
the more you have stored, the farther and faster you can run. In addition, if
you eat properly after heavy training, you can actually store more glycogen than
if you ate improperly. So you could cover even more distance at a fast pace. Is
fat used for energy in soccer? Yes, during low intensity work like walking and
slow jogging. You won't run out of fat for fuel, but you can run out of
glycogen. You need glycogen to go fast - remember, soccer is not played at a
walk.
Do we know anything about muscle glycogen and soccer?
Plenty.
1. Most soccer players make poor food choices (too
much protein and fat) so they enter games with less than a full tank of gas
(less muscle glycogen than most athletes should have).
2. Most the glycogen in the muscles is used in the
first half of a game. By the end of the game, glycogen levels are almost zero.
Your sprints get shorter and less frequent as the game goes on.
3. The more glycogen, the further and faster players
run. A research study showed that players who ate lots of carbohydrate ran the
most and only walked about 25% of the total distance. Players who ate a "normal"
meal covered about 25% less distance and covered most of it at a walk. Can you
guess who won this game?
Any suggestions for soccer players when choosing
foods to eat?
·
Choose foods with the
highest carbohydrate and lowest fat count. Carbohydrates should make up 55-65%
of the diet. Choose, for example, bagels over sliced bread, baked potato over
french fries, a high carbohydrate cereal over a low carbohydrate cereal (read
those labels!).
·
A teenage or adult
athlete should eat 450-600 grams of carbohydrate a day (spread it out over 24
hours-think you can eat that amount of spaghetti in one sitting? That's over 2
dry pounds of spaghetti!). Younger players would eat less because they are
smaller. The rough formula is 7-10 grams/kg/day.
·
If you make poor food
choices and train regularly, you can't refill your glycogen levels before
tomorrow's practice. Thus, glycogen levels stair-step down as the week goes on.
It is important to eat plenty of carbohydrates during training, not just for
matches.
·
Your muscles are the
most "thirsty" for glycogen right after exercise.
So try to eat a good supply of carbohydrates within
the first 2 hours after play. Don't wait. Have carbohydrate rich foods available
right after a game. This is especially important if you are playing in a
tournament with many games in a short time. Give yourself every advantage and
refuel for the next games. Choose fruit juices, carbohydrate replacement drinks,
bagels and jam, fresh or dried fruit, uncooked "Chex Mix" types of finger food.
If candy is acceptable to your parents, choose "clear" candy like "gummi" bears,
jelly beans, etc. (chocolate-based candy has too much fat and calories). Stay
away from the chips, burgers, fries, nachos, etc.; too much fat and not enough
carbohydrates.
The smart athlete will try to give himself or herself
every advantage to help their team to win. Knowing you are going into a game
with a "full tank of gas" means you are ready for the highest demands of the
game. Also, if you have eaten properly and are playing a team who played
yesterday (who likely hasn't eaten properly), you know you are at an advantage
and will be fresher in the second half.
This sports science article comes from the Sports
Medicine Section at the Duke University Medical Center and UNC Hospitals. The
authors are members of the US Soccer Sports Medicine Committee including from
UNC Dr. William E. Garrett, Jr (US National Teams Physician and Committee
Chairman), and John Lohnes. From Duke are Dr. Don Kirkendall (exercise
physiologist) and Patty Marchak (athletic trainer for 1996 US Women's Olympic
Team).