This week I am writing about why lactate accumulation is advantageous to the body.  Using the article given by Coach Kirkton, I found some reasoning why it helps out the body. The body can experience multiple kinds of muscle fatigues, the first is caused by a build up of K+, which depolarizes the fiber and prevents Na+ channels from recovering. Another type is called “metabolic fatigue” due to the indirect/direct accumulation of metabolites and a decrease in substrates within the fibers. It can also occur from glycogen depletion.  The accumulation of lactate causes a change in pH within the muscle fibers, which actually slows the onset of fatigue. The pH changes from 7.1 to less than 6.7 which causes the solution to be acidic. This acidity increases the Ca concentration and help activate the contraction. The pH also counteracts the inhibitory affects of the raised [K+]. In short, the lactate accumulation helps prevent or slow down the failure of the action potential of the muscle fibers.

I also found another article, titled “Lactate: valuable for physical performance and maintenance of brain function during exercise”.  Not only can lactate slow the high [K+] but also noxious metabolites such as Inorganic phosphates. They also facilitate the removal of muscular proton and acts together with catecholamines to work in reducing fatigue. Lactate also regenerates NAD+ which is used within glycolysis to produce energy. Lactate is also important for cognitive function, it ensures that inhibitory signals within the CNS are detected, so it protects neurons from damage by acidosis.

For a long time lactate has been seen as a waste product but it actually an alternative energy source that the body can use to recover and continue to work. It not only does it help the body during exercise but also when the body is at rest. This is why lactate accumulation is helpful and advantageous for the human body.

Source: https://academic.oup.com/biohorizons/article/doi/10.1093/biohorizons/hzu001/242608#26872984