Question

After a vigorous exercise or work we feel pain in muscles. What is the relation ship between pain and respiration?

Answer 1

Answer:

When muscles pull or strain or stretch during a vigorous exercise, we feel a lot of pain. There is burning sensation in those muscles.

This sensation is due to lactic acid, which is produced in the muscles. Our body's response system tries to get more oxygen to the muscles. It is not possible to give sufficient oxygen immediately. So the muscles shift from aerobic (with oxygen) respiration to anaerobic respiration (without oxygen).  Both processes produce ATP.  Anaerobic respiration produces more toxins.

So liver has to do more work to remove the additional toxins. When sufficient oxygen is available to the muscles, the respiration shifts back to aerobic.