Question

Give reasons of we need more oxygen during heavy exercise.

Answer 1

The lungs bring oxygen into the body, to provide energy, and remove carbon dioxide, the waste product created when you produce energy. The heart pumps the oxygen to the muscles that are doing the exercise. When you exercise and your muscles work harder, your body uses more oxygen and produces more carbon dioxide.

Answer 2

because during exercise our brain need more oxygen to work and our body need energy which is present in oxygen