The human body prefers to generate most of its energy using aerobic methods, meaning with oxygen. The oxygen helps to convert glucose into energy. Some circumstances, however, require energy production faster than our bodies can adequately deliver oxygen. In those instances, the working muscles generate energy anaerobically. The body produces lactic acid when it is lacking in the oxygen it needs to convert glucose into energy. The lactic acid allows glucose breakdown—and thus energy production—to continue.

People often experience high levels of lactic acid during or following strenuous exercise. This is called exercise-induced or exercise-related hyperlactatemia.

Lactic acid buildup can result in muscle pain, cramps, and muscular fatigue. A buildup of lactic acid in the muscles during or following exercise is usually not harmful. In fact, some experts believe it can be beneficial. In small amounts, lactic acid can:

• help the body absorb energy
• help the body burn calories
• increase endurance levels

However, a lot of people find that the muscle pain and cramps from lactic acid buildup can negatively affect their workouts. To combat the unpleasant effects of lactic acid buildup, be sure to stay well-hydrated, take more breaks or decrease your exercise intensity.

And unfortunately, some people may be at risk for lactic acidosis, a condition that causes lactic acid to build up in the bloodstream. Most lactic acid moves through the bloodstream to the liver where it is broken down — but people with liver problems are not able to do this as effectively when exercising. Other people that may be at risk for lactic acidosis include those with conditions that cause low blood pressure.

If you have risk factors, be sure to check with your doctor before starting a new workout routine.