How Lactic Acid Affects Your Athletic Performance

Woman running along the reservoir in Central Park
JGI/Tom Grill/Getty Images

There is a misconception about lactic acid among athletes and sports enthusiasts. However, there is plenty of research about lactic acid in recent years that debunks many of the myths that lactate impairs performance. In fact, now it is believed that lactic acid actually provides another fuel source for working muscles.

What Is Lactic Acid?

Lactic acid is formed from glucose and used by working muscles for energy. Now it is thought that muscle cells convert glucose or glycogen to lactic acid. The lactic acid is absorbed converted to fuel by mitochondria in muscle cells.

Lactic Acid Is the New Muscle Fuel

Lactic acid may still be behind the burning sensation during intense exercise but new research has confirmed that delayed onset muscle soreness is from microscopic tears and trauma as a result of physical exertion. Lactic acid was always seen as a by-product of metabolizing glucose for energy and a waste product that caused a burning sensation in the muscles.

However, research shows that lactate accumulation may assist to relieve the burn or muscle cramp created during high-intensity physical activity.

Lactate Threshold Training and Peak Performance

By training at a high intensity (lactate threshold training) it is thought that the body creates additional proteins that help absorb and convert lactic acid to energy. At rest and under low-intensity exercise there is an even rate of lactic acid production and blood lactate removal.

As your intensity of exercise increases, the imbalance causes a build up in blood lactate levels which are the lactate threshold is reached. At this lactate threshold, blood flow is decreased and fast twitch motor ability increases. This peak level of performance is referred to as lactate threshold training.

Aerobic and Anaerobic Training

Your lactate threshold marks the transition from aerobic training to anaerobic training. When referring to your training zone, trainers suggest that to improve endurance and efficiency, you must train in the anaerobic zone, that is beyond the lactate threshold.

Team USA running coach Dennis Barker shares why that aerobic training doesn't improve performance because in that state your body is receiving enough oxygen to meet the demands of the exercise. However, during anaerobic exercise, your body is not getting enough oxygen.

Reaching this threshold helps your body become more efficient by training at or just below lactate threshold, thus anaerobic training is essential to improving your athletic performance.

Heart Rate, Lactate Threshold, and Peak Performance

Everyone has a maximum heart rate. If it is 205 beats per minute (bpm), then your lactate threshold would be just around 185 bpm. This would make your aerobic training zone between about 125 and 185 bpm.

To maintain your aerobic fitness, you'd work in that zone, at which you would be able to comfortably talk. However, to enhance your aerobic training, you'd have to workout at or near your lactate threshold.

In the end, lactic acid, or the push toward your lactate threshold is actually a good thing that could improve your athletic performance, if you push yourself toward your peak.

Was this page helpful?

Article Sources

  • Brooks GA, et al. Lactic Acid Accumulation Is an Advantage/Disadvantage During Muscle Activity. Journal of Applied Physiology. June 2006