What occurs when more lactic acid is produced than can be transported away?

When more lactic acid is produced than can be removed from the muscle tissue, it accumulates, leading to a buildup that causes a burning sensation and fatigue in the muscles. This process typically occurs during intense exercise when the body’s demand for energy exceeds its oxygen supply, resulting in anaerobic metabolism.

As lactic acid accumulates, it alters the pH in muscle tissues, which contributes to that characteristic burning feeling. This accumulation signals the body to slow down or stop the activity to recover and clear the excess lactic acid. The sensation of fatigue and discomfort is a way for the body to indicate that it's reaching its limits and needs a break or a reduction in intensity to recover and restore balance.