Hormones play important roles in providing energy to the muscles and
nerves. They are also involved in replacing that energy. In addition, they play
roles in repairing and building tissues. The following are some of the most
important functions that hormones perform for athletes.
Endurance work increases the use of glucose by muscles. The following
hormones facilitate the use and replacement of muscle glucose. An increase in
secretion of the hormone glucagon facilitates the movement of glucose from the
liver to the blood, which carries it to the working muscles. The hormones
epinephrine (adrenaline) and norepinephrine are also secreted in additional
amounts. They aid in the movement of liver glucose to the blood. The secretion
of cortisol facilitates the conversion of liver glycogen to glucose. The increased
secretion of the hormone insulin, is directly involved in transferring blood
glucose into the working muscle fibers.
