SORU: aşağıdaki parçaya göre cevaplayınız
It is clear from the passage that, during prolonged physical activity, ----.
Muscles can obtain the carbohydrate they need, not only
from glycogen stores but also from sugar taken during
activity, which elevates blood glucose and enhances
endurance. Normally, insulin stimulates all the tissues of
the body to drain glucose from the blood and store it;
however, this is exactly the opposite of what is needed
for performance. During physical activity, the body's
release of the hormone epinephrine keeps insulin from
rising in response to glucose entering the blood.
Physical activity also enhances muscle sensitivity to
insulin so that the muscles become the primary recipient
of blood glucose. Consuming sugar is especially useful
during exhausting endurance activities lasting more than
an hour. Endurance athletes often run short of glucose
by the end of competitive events, and they are wise to
take light carbohydrate snacks or drinks periodically
during activity. During the last stages of an endurance
competition, when glycogen is running low, glucose
consumed during the event can make its way slowly from
the digestive tract to the muscles and increase the
body's supply of glucose enough to prevent exhaustion.