What is one effect of lactic acid buildup during physical activity?

The buildup of lactic acid in muscles during intense physical activity is primarily associated with cramps and muscle fatigue. When the body exercises at a high intensity, it may rely on anaerobic metabolism for energy production, leading to the accumulation of lactic acid as a byproduct. This accumulation can lower the pH in the muscle cells, causing discomfort and a burning sensation, which often results in cramps. Additionally, the presence of lactic acid can impair muscle function and lead to fatigue, as it disrupts the normal balance of ions and promotes the perception of tiredness in the muscles. This effect highlights the importance of understanding how the body responds to different intensities of exercise and the implications for performance and recovery.