Far away were the times in which it was thought that the laces were because of lactic acid. However, this substance resulting from the metabolism of sugar is largely responsible for the fact that in an exercise session we begin to accumulate fatigue and eventually withdraw.

The lactic acid comes from the breakdown of glucose when there is no oxygen present (glycolytic metabolism), i.e. in an anaerobic exercise as would be lifting weights or running at high speed, where high intensity and short duration. In normal conditions that lactic acid and when we are trained is reused and there is no major problem.

But when we vigorously follow an exercise, lactic acid will begin to accumulate by not giving the body time to remove it. This causes acidification of muscle fibers, which has two important consequences:

• The enzymes in charge of breaking the molecule of glucose to obtain energy are inhibited, so that we are cut off the energetic grigo of this way and as we know, if there is no energy, there is no movement.
• Calcium is prevented from binding to the muscle fibers and consequently from contraction.

Therefore, when there is a lot of lactic acid in the body, we have neither the energy nor the capacity to contract the muscles, this is nothing but fatigue and the best thing we can do is to stop the exercise or activity.

How can we avoid lactic acid? With training, there is no more. On the basis of training, the body deploys adaptive mechanism that causes the lactic acid does not accumulate so quickly and if it starts to do so, the muscle will support it more effectively.