Normally, the body's total expenditure of energy on breathing is about 3%. To what percentage can it increase in highly trained athletes during maximal intensity exercise?
a. 5%
b. 8%
c. 15%
d. 18%
Answer: c. 15%
In highly trained athlete total expenditure for breathing can increase to as much as 15% while performing maximal intensity exercise. Most people will see an increase up to only about 10% during maximal intensity and up to 5% for moderate level intensity exercise.