When we exercise, our muscles do more work and therefore need more energy. They get this energy from food, which is broken down during respiration. Respiration uses up Oxygen and so we breathe faster to supply the extra oxygen our muscles need when we exercise.When we are sitting or standing, we breathe in and out only about 10 percent of the air in our lungs. When we exercise hard, this figure goes up to about 60 percent.
Answers
Mr.Aashitosh Pandey
When we exercise, our muscles do more work and therefore need more energy. They get this energy from food, which is broken down during respiration. Respiration uses up Oxygen and so we breathe faster to supply the extra oxygen our muscles need when we exercise.When we are sitting or standing, we breathe in and out only about 10 percent of the air in our lungs. When we exercise hard, this figure goes up to about 60 percent.