Alcohol along with
tobacco, is the most popular drug in the Western World. The majority
of athletes who consume alcohol do so for 'social' reasons. Although
it is a drug, it may also be classified as a nutrient because it provides
energy at about 7 kcal per gram. But that really is pushing the definition
of 'nutrient' to the limit. Beer, wine and spirits are high in calories
and low in everything else.
There are a lot
of dubious claims made about alcohol and athletes. It is commonly believed
that beer is a good source of carbohydrate and will therefore help boost
glycogen levels before and after training sessions. This is not the
case. Although a 12oz can of beer does contain about 150 calories, only
50 of them are derived from carbohydrate, the rest coming from alcohol.
Muscles can't take the calories from alcohol and convert them into glycogen,
so the amount of energy you derive from a glass of beer is negligible.
Another misconception
about beer is that it will provide you with a high intake of vitamins
- particularly the B vitamin group. In fact, it would take eleven cans
of beer to obtain the recommended intake of vitamin B12 (riboflavin),
and significantly larger amounts to get an adequate intake of other
vitamins.
The main ingredient
of alcoholic drinks is ethanol, which is produced by fermenting sugar
or starch with yeast. It is during the fermentation process that alcohol
gets its characteristic flavours and aromas. The substances responsible
for giving each drink its individual taste are called congeners. They
are also to blame for the adverse effects which excessive intake has
on people. For example, it is the congeners in red wine which can cause
a throbbing headache, rather than the alcohol content of the drink.
However, psychologically
and physiologically, it is the alcohol which causes problems and athletes
are as prone to these as anyone else. The average person will probably
experience mild physiological changes after only a couple of drinks.
These include a faster heart rate and a flushed face are familiar signs.
Although at this stage the intellectual processes aren't exactly impaired,
decision-making takes longer after even a few drinks. The adverse psychomotor
effects of even low levels of alcohol have implications for athletes
in games requiring great skill such as racquet sports. If the ability
to react quickly is impaired, then the consequences will quickly become
evident. A number physiological effects could also be detrimental performance.
For example, alcohol may depress heart function, interfere with liver
function and lead to dehydration by suppressing the release of anti-diuretic
hormones.
When someone drinks
alcohol, it diffuses into the body tissue and then is broken down by
the liver. On average it will take the liver about an hour to break
down one unit of alcohol. And what is classified as one unit of alcohol?
This is typically the amount found in 12 ounces of beer, 4 ounces of
wine or 1.25 ounces of spirits. Therefore, large amounts of alcohol
can take up to twelve or fourteen hours to be metabolized depending
on the height, weight and gender of the person.
For athletes, the
message in the bottle is that alcohol is not harmful in itself provided
it is taken in moderation and avoided in the hours before training or
competition.
Alcohol Facts
* It is a diuretic i.e. it causes your body to lose fluid and dehydration
results if the fluid is not replaced.
* It cannot be used by muscles as energy for exercise.
* It is metabolized at a fixed rate. A large intake of alcohol will
remain in the blood until the liver can break it down. Exercise will
not speed up the rate at which your liver metabolizes the alcohol in
your body.
* Even taken in small doses, alcohol can affect coordination and reaction
times.
November 1994