In a lactate test, the so-called lactate value in the blood is determined to determine the fitness level of a person. Lactate is produced directly in the muscles and is a salt of lactic acid. The lactate value of a person at rest is one milli mol (mmol) of lactate per liter of blood.
This value can rise to 25 mmol lactate per liter of blood under stress. This metabolic product is produced during intensive endurance training, at the beginning of heavy static muscle work and during rapid strength training (longer sprinting distances). The energy required for this is mainly produced by splitting ATP.
ATP is adenosine triphosphate, in simple terms a very energy-rich molecule. It is important that when ATP provides energy, a hydrogen ion (proton) is split off and remains in the muscle. A certain number of this proton (H+) can lower the pH value.
The pH value of the muscles is normally neutral (7). If the value falls below seven, then we speak of an acidic pH value. A lowering of the pH-value can lead to cell damage.
For this reason the body has developed a defense mechanism. To bind the protons, the body produces more lactate. During the formation, protons are bound and the overacidification of the muscle is counteracted.
This protective mechanism reaches its limits at some point. If the pH value in the muscle cell continues to drop while the number of protons continues to rise, then the protons ultimately block the ATP cleavage and the muscle cramps (colloquially: closes up). The lactate thus ensures that a highly intensive load can continue for a certain time before the muscle cramps. The more lactate there is in the blood, the higher the number of protons in the muscle, and the greater the strain on the body. The amount of lactate in the blood can be used to determine the degree of stress and the ability of the body to maintain intensive loads for a certain time.
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