Everyone has experienced that point at which your muscles are burning and it gradually gets harder to complete or compete in sporting events. Do not be mistaken this is NOT lactic acid this is the formation of lactate.
Lactate, formed from pyruvate being catalysed by the enzyme lactate dehydrogenase. Pyruvate being the by product of Glycolysis (10 second to 3 minute events) is now being transferred along to fuel further exercise. This process happens when energy demand is high and energy must be transfered at a high rate. However, instead of lactic acid being the by product of this process it is in fact anion lactate and Hydrogen ions (H+).
However, it is not lactate that can be the sole blame for the experience of muscular fatigue. With the increase accumulation of H+ which reduces intracelluar pH, inhibits glycolytic reactions and interferes with muscle contractions. That moment say when you come to that very last mile of a marathon and legs just wont do what your telling them to. This is the interference of muscle contractions inhibiting calcium to bind to troponin which further interfering with the cross bridge recycling (poor muscle contraction). However, research has suggested a process called Hydrolysis to be the cause of all the H+ accumulation and not lactate. Even more contraversial is lactate can be used as an energy substrate particualry in slow twitch fibres (type 1) and cardiac muscle. Using lactate as an energy substrate is also useful for those competing in long endurance events when process called gluconeogenesis is called upon to use glucose from non carbohydrate sources.
Lactate has both pros and cons being used as an energy substrate is great BUT only in certain circumstances. However, when we are looking at performing rapid sharp movements maybe say over the course of a 1500 meter track the on set of blood lactate really is not ideal. The point at which this happens is not ideal, both painful and frustrating the individual needs to delay the onset of blood lactate (OBLA). This is at the point we begin to discuss anaerobic threshold training and what you can do.