If an outdoor runner develops a headache, feels tired, and has an elevated heart rate, what is the most probable cause?
a. lack of protein
b. dehydration
c. overhydration
d. insufficient calories

If an outdoor runner develops a headache, feels tired, and has an elevated heart rate, the most probable cause is Dehydration. The answer is letter B. Because while exercising, you are sweating a lot and your body excretes water. The more you excretes water, the more dehydrated you become and so you need water to replenish dehydration.

answer; i believe the correct answer is (progesterone);

what effect does exercise have on the nervous system?

the answer is c.