How does the body utilize lactic acid during metabolism?

The body utilizes lactic acid primarily by converting it back to glucose in the liver when oxygen becomes available. This process is part of the Cori cycle, wherein lactate produced during anaerobic glycolysis, particularly during intense exercise when oxygen supply is limited, is transported to the liver. Here, the lactate undergoes gluconeogenesis to form glucose. This newly synthesized glucose can then be released back into the bloodstream and transported to tissues that need it for energy, effectively recycling the lactic acid.

The other options do not accurately reflect the metabolic fate of lactic acid. While some lactic acid may be temporarily accumulated and could be cleared, it is not typically discarded as waste immediately. Instead, it serves a crucial role in energy metabolism, especially during periods of high energy demand. Additionally, lactic acid is not directly converted into fat for storage, and it does not decrease energy expenditure; instead, it can serve as an important energy source during recovery from strenuous exercise.