Carbohydrates Fuel Athletic
By Nancy Brinch, MS, RD, LSW
seen the ads touting low carbohydrate diets such as Dr Atkins'
New Diet Revolution or Protein Power. Proclaiming that carbs make
us fat, these diets shun pasta, bread, potatoes, rice, cereals,
and fruit in the name of weight reduction. It's the anecdotal
reports of astounding weight loss from proponents of these diets
that lures people into following this approach. Their hope is
to lose weight while eating unlimited quantities of their favorite
Should athletes follow the low carbohydrate
The issue of incorporating carbohydrates in the diet is especially
critical for athletes seeking an edge to improve their performance.
Let's start with some basic facts:
|Carbohydrates are the body's main
source of energy and the only source of energy for the
brain and the nervous system.
|Carbohydrates spare protein so
it can be used to build and repair muscles and make enzymes,
hormones and antibodies rather than being used to fuel our
|Carbohydrates are essential for fat
metabolism. Without sufficient carbohydrate fat cannot
be burned completely.
|Carbohydrates are stored in our muscles
and liver to be used as energy between meals and snacks.
This storage of carbohydrate is essential for athletic performance.
Because carbohydrate (in the form of glucose) is absolutely essential
for the brain and the nervous system, the body goes to great lengths
to maintain an adequate blood glucose level. If the blood glucose
falls too low we experience signs such as hunger, dizziness, shakiness
weakness, rapid heartbeat, and anxiety. Obviously these symptoms
can seriously impair athletic performance. To avoid this, the
body stores glucose in the form of glycogen in the liver. This
liver glycogen can be broken down to glucose and released into
the blood whenever the blood sugar level falls too low. Glycogen
is also stored in the muscles to fuel muscle contraction. The
amount of glycogen stored in muscles can be a limiting factor
for athletic performance. If the muscle glycogen becomes depleted
due either to a low carbohydrate intake or exercise, muscles cannot
function at peak level. In this scenario protein becomes a source
of glucose because some of the building blocks of protein can
be converted to glucose. When this occurs lean muscles tissue
The bottom line:
If you don't have enough carbohydrates in your diet you won't
be able to continue doing high intensity activities. What are
the best sources of carbohydrates for athletic performance? The
answer depends on the timing of carbohydrate intake. During exercise
and immediately afterward carbohydrates that are quickly digested
and absorbed are the best
They provide a source of glucose to fuel exercise and to replenish
glycogen stores after exercise. These so-called "high glycemic
index" carbohydrates include foods such as most breads (i.e. white
bread), most breakfast cereals (i.e. cornflakes), sports drinks,
white potatoes, and sodas. Before exercise, eating low or moderate
glycemic index carbohydrates provides a sustained level of blood
glucose. This even level of blood glucose enhances athletic performance.
These carbohydrate foods include juice, most fruits (i.e. apple,
orange, banana), rice, yogurt, milk, oatmeal, chickpeas, lentils,
kidney beans, most pastas, muffins, crackers and most cookies.
The recommended amount of carbohydrate for athletes is 3 or 4
grams of carbohydrate per pound of body weight per day. Higher
levels are required during periods of intensive exercise. Nutrition
labels are a good source of information on carbohydrate content
of foods. Another source is the USDA National Nutrient Data Base