Does race matter? The role of race in the blood lactate levels of sub-elite runners.

Abstract

Lactic Acid is a byproduct of anaerobic metabolism. In the absence of oxygen, pyruvate undergoes fermentation instead of entering into the pyruvate dehydrogenase complex, which occurs during aerobic glycolysis. During fermentation, pyruvate is reduced to lactate. At about 50-70% of VO2max, there is a substantial increase in lactate accumulation, otherwise known as the Lactate threshold. At this work rate, energy is obtained from glycolysis. Glycolysis at high intensity exercise increases CO2 levels which in turn trigger an increase in ventilation and heart rate. This system is short lived and fatigue sets in quickly due to glycogen depletion, a decrease in pH due to excess H+ ions, and many other factors. Blood lactate levels are a reflection of the amount of lactic acid present in the muscle.