What temporary physiological advantage does the substantial increase in chest circumference....?

Question

during forced inspiration create?

Answer 1

Maximum possible oxygen gets into lungs to be circulated in blood and collect maximum carbondioxide from tissues.

Answer 2

it allows all the lung alveoli to expand, which allows gas exchange. without maximal expansion, you'll have atelectasis (collapsed alveoli) which won't be able to absorb o2 nor co2.