| While
there has been new research showing that coffee may
not be as harmful to your health as previously thought,
a new study has shown that there’s one time that
you should hold off on that java jolt: It’s not
a good idea to drink coffee or other beverages containing
caffeine before exercising.
Swiss
researchers gave healthy men and women the equivalent
of about 200mg of caffeine—the same amount that’s
found in two cups of coffee—then had them exercise
for about 45 minutes. While they exercised, the researchers
changed the altitude for half the group. This induces
a drop in oxygen, which would be similar to what a person
with heart disease experiences.
The
researchers found that those test subjects who exercised
with caffeine in their system and depleted oxygen had
a nearly 40 percent dip in coronary circulation. This
led the researchers to speculate that caffeine blocks
the chemical signals that normally cause coronary blood
vessels to expand during exercise.
Other
studies on caffeine have shown that it makes the heart
work harder by raising blood pressure and heart rate.
But since this study shows caffeine restricts blood
flow during exercise, researchers say that in theory
caffeine could trigger a heart attack, although more
studies need to be done to confirm these results.
In
the meantime, the advice is to make sure you wait a
certain amount of time between drinking coffee and exercising.
Nobody has determined just how long a wait that time
should be, but it generally takes at least 90 minutes
for a caffeine boost to dissipate.
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