$Unique_ID{BRK01172}
$Pretitle{Blood and Blood Forming Organs}
$Title{Is Exercise Good for the Blood?}
$Subject{exercise blood risk factors}
$Volume{D-23, D-7}
$Log{}

Copyright (c) 1991   Tribune Media Services, Inc.


Is Exercise Good for the Blood?


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QUESTION:  My boy friend claims that his exercise program is good for his
blood.  Is it possible that there are changes that are cause by his physical
activity which may be consider to be of benefit to him?

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ANSWER:  Regular exercise does causes several changes in your blood, but these
are helpful ones.  As you know, regular exercise reduces the risk of a heart
attack by lowering blood pressure, reducing body fat and blood cholesterol
levels, and making the heart more efficient.  The change that occur to the
blood may also have a role in helping protect the heart.
     The major exercise-related changes in blood are a decrease in hemoglobin
concentration, a decrease in platelet activity, and an increase in
fibrinolysis.  These changes appear to reduce the risk of thrombosis, the
formation of a clogging blood clot within a blood vessel.  A heart attack is a
blood clot within one of the arteries supplying the heart, so any reduction in
the risk of thrombosis is a lessening of the risk of heart attack.
     While a decrease in the concentration of hemoglobin in athletes sounds
like bad news, it is not due to a shortage of red blood cells, but to an
increase in the amount, or volume, of blood plasma, the liquid portion of
blood.  This increase in plasma volume is a good sign of aerobic fitness.
Increased plasma volume makes blood less viscous, which may decrease the risk
of thrombosis.  Any reduction in oxygen-carrying capacity is offset by
increased heart efficiency and sweating during exercise.  The drop in
hemoglobin concentration is sometimes called "athletes' anemia" or
"pseudoanemia," but these are misnomers.
     Regular exercise also appears to decrease the aggregation of platelets,
the cells within blood that forms clots.  Platelet aggregation is the first
step in the formation of a blood clot.  This effect may also decrease the risk
of thrombosis and may reduce the risk of heart attack.
     The third way that exercise changes the blood is by activating
fibrinolysis, the body's way of getting rid of old blood clots.  This increase
in fibrinolysis is greatest in those that exercise most, and so people who are
the most physically fit appear to dissolve clots faster than those who are
less fit.
     The key to all this is regular exercise, especially aerobic exercise such
as running, cycling, brisk walking, or aerobic dancing.  The word "regular"
cannot be stressed enough.  To get the benefits of exercise, you must do it
for at least a half an hour and at least three times a week.
ÿ
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The material contained here is "FOR INFORMATION ONLY" and should not replace 
the counsel and advice of your personal physician.  Promptly consulting your 
doctor is the best path to a quick and successful resolution of any medical 
problem.
