LACTATE METABOLISM AND THE EFFECT FOR SPRINTER PERFORMANCE

The ability to achieve and maintain speed is the main determinant of success in sprinter. The energy needed by sprinter from both phosphocreatine and anaerobic glycolysis, with each source contributing about 50%. Lactate is produced in muscle cells during a run will diffuse into the blood. In most cases, the diffusion rate is slower than the rate of production, so that after running intensive, lactate concentration increased in the 5th minute until the 10th. The high concentration of lactate during 10 minutes restitution shows the strong involvement of anaerobic glycolysis. Increased levels of lactic acid of high occurred during practice or game on a sprint runner can affect the performance of athletes. Furthermore, the lactic acid in the muscles will disociate into H+ ions and lactate ions. Increased H+ ions causes a decrease in pH in the extra and intracellular fluid. This decrease in pH will affect and inhibit the binding of oxygen by hemoglobin in the lungs, and can inhibit the activity of the enzyme phosphofructokinase and myofibril ATPase enzyme in the muscle that plays a role in the synthesis of ATP thus providing energy during muscle contraction becomes impaired. Disruption of energy supply will reduce the ability of muscle contraction. If the decreased ability of muscle contraction, it will lower the running speed of sprinter.