Answer: A. Regular participation in physical activity reduces the risk of developing various diseases.
Answer: Oxygen gets carried away on the red blood cells, and carbon dioxide is expelled into the air. The exchange of these two gases takes place without much fanfare when the body is at rest.
A rapid rate of breathing can occur normally after exercise. In addition, panic states and high altitude climbs can also raise the respiratory rate. When these conditions occur, individuals may have a variety of symptoms related to pH changes in their bodies caused by the hyperventilation
Your body needs oxygen to breathe, which it takes from the air around you, into your lungs, to your heart - where it is pumped to your muscles and organs. When the oxygen is used by your muscles, carbon dioxide is produced, which needs to be removed. So as the new oxygen goes into your muscles, the carbon dioxide from the last pump is taken out, where it is sent all the way back round to the heart, and then back to your lungs, and out of your mouth, back into the air.
So, rebreathing breathed air increases the carbon dioxide concentration in you blood, triggerring you body's response of increased breathing in an attempt to regain oxygen and get rid of carbon dioxide.
Explanation:
