Final answer:
During heavy exercise, lactic acid is produced in our muscles and enters the bloodstream, which can lead to metabolic acidosis. This is because the lactic acid is neutralized by bicarbonate ions, forming carbonic acid and reducing blood pH. Breathing helps eliminate carbon dioxide and maintain the pH balance.
Step-by-step explanation:
During heavy exercise, lactic acid is produced in our muscles. This lactic acid enters the bloodstream and can contribute to the development of metabolic acidosis. Lactic acid is neutralized by the bicarbonate ion (HCO3-), forming carbonic acid (H2CO3). This carbonic acid can then break down into carbon dioxide and water, which can be eliminated through breathing. This process helps regulate the pH of the blood. Therefore, heavy exercise can cause metabolic acidosis due to the production of lactic acid and the resulting decrease in blood pH.