Definition and hints
From a chemical point of view, lactic acid (C3H6O3) is defined as a carboxylic acid whose deprotonation gives rise to the lactate ion.
In human physiology, lactic acid constitutes the waste of energy production in the absence of oxygen, or rather anaerobic glycolysis.
For some physiological systems the production of lactic acid is absolutely normal (red blood cells), but the vast majority of body tissues mainly exploit the aerobic metabolism (ie in the presence of oxygen); muscle tissue is one of them.
Lactic acid and sports performance
The stimulation of lactacid metabolism occurs effectively through the execution of repetitions above the anaerobic threshold or rhythm variations above the anaerobic threshold; remember that the anaerobic lactacid metabolism is very useful thanks to the rapidity with which it delivers energy, but on the other hand, it is extremely limiting as the accumulation of lactic acid represents an element of great muscular fatigue and therefore limits the continuation of performance.
Lactic acid is disposed of through the neoglucogenesis or Cori cycle, ESPECIALLY in the liver, reached through the circulatory system, and to a lesser extent in the skeletal muscle and heart. disposal of "lactic acid does NOT last beyond 120", moreover, lactate is NOT responsible for post-exercise muscle pain (in English Delayed onset muscle soreness-DOMS), instead caused by the release of intracellular molecules (due to microlacerations) as a result of very intense training and above all with "eccentric" efforts. These molecules generate a real localized inflammation, effectively stimulating the neuromuscular endings and inducing the sensation of PAIN.
Dispose of lactic acid
In sports performance, the ability to produce lactic acid, to tolerate muscle concentrations and to dispose of it quickly, are qualities deliberately sought through different and specific workouts.
In order to reduce the symptoms induced by attic acid, the athlete should:
- Strengthen the mechanisms of disposal (muscle vascularization, hepatic and muscle enzymatic increase, and increase of buffer systems)
- Carry out activities useful for disposal (muscle de-fatigue or active recovery between one repetition and the other, or reduction of intensity to a de-fatiguing level during rhythm variations)
- Ensure the intake of magnesium and possibly integrate with alkalizing products
Remedies for lactic acid
As already specified, lactic acid is a "waste" molecule that is actually very useful, as it represents a potential neoglucogenic substrate from which to obtain glucose from scratch. Obviously, in the event that the production of this catabolite exceeds the capacity of disposal, there would be an accumulation of acid molecules responsible for the decline in muscle performance and systemic fatigue. In physiological conditions, the "acidification of the blood induced by" lactic acid is absolutely harmless and even during maximum performance SHOULD not cause any type of acute complication, obviously, assuming that the athlete or sportsman in question is physically healthy, well hydrated and eunnourished. However, in order to improve the performance of the disciplines that massively involve the anaerobic lactate metabolism, sports technicians and nutrition professionals have begun the search for different remedies to counteract the accumulation or reduce the symptoms; it is however necessary to specify that no nutritional intervention and no food supplement can replace specific training to increase lactacid tolerance.
1) Magnesium (Mg), a natural alkalizer
Magnesium is a trace element widely found in foods but whose need drastically increases in athletes and especially in endurance athletes. Its concentration in extracellular fluids is essential for maintaining the membrane potential of nerves and muscles as well as for transmission of the nerve impulse, two physiological processes SEVERELY compromised by the accumulation of lactic acid. It can be deduced that a magnesium deficiency (even if not excessive but chronic) could negatively affect the maintenance of prolonged and high intensity muscle stimulation; therefore, it is not Chronic magnesium insufficiency is rarely confused with lactate buildup induced by excessive training intensity. Such a situation could literally mislead the sports technicians by inducing them to lighten the training schedules and consequently frustrate the whole organization of the annual program. In the long term, the magnesium deficiency COULD simulate in a more than realistic way the symptoms of overtraining or over training. -training.
LARN quote: "Magnesium homeostasis is substantially guaranteed by renal function and by the modulation of absorption in the intestine ... Given the widespread presence of magnesium in food and the high efficiency of magnesium retention by the kidney, there are no known cases of deficiency SPONTANEOUS diet of magnesium. Magnesium deficiency is manifested by impaired metabolism of calcium, sodium and potassium which results in muscle weakness, impaired heart function and even tetanic crises'.
Magnesium is present: in green vegetables, bananas, legumes, whole grains and dried fruit, even if more than 80% of the magnesium is removed by cereal refining treatments. In healthy NON-sports subjects, intakes from 3 to 4.5 mg / kg are sufficient, however, there is a lack of data to establish the right recommended intake level; the recommended safety interval is 150 to 500 mg / day.
Magnesium does not intervene directly on the lactic acid buffering system but its deficiency can aggravate the symptoms of muscle accumulation, therefore, among the remedies against the undesirable effects of lactic acid it would be desirable to introduce an adequate dietary regimen, probably supported by the " dietary supplement of magnesium.
2) Bicarbonate
Bicarbonate is a physiologically alkalizing molecule produced by the organism that falls within the buffer system; it includes bicarbonate, phosphate, amino acids (such as histidine) and some proteins (such as hemoglobin). The bicarbonate reacts by binding the hydrogen ions (H +) released by acid substances (such as lactic acid) reducing their acidification potential. It can be used as a food supplement if taken from 30 "to 2 hours before performance; in fact, a study on middle-distance runners has shown that the administration of sodium bicarbonate equal to 300mg per kg of body weight increases both the bicarbonate concentration and the blood pH with a relative improvement in race performance. A further study was carried out on a female sample who, with the same administration, in "carrying out a maximum effort of 60" obtained an improvement in the extracellular buffer system.
The side effects of excessive sodium bicarbonate supplementation are enteric in nature (diarrhea) and affect 50% of athletes who use it. The optimal intake could be 300mg (0.3g) of bicarbonate per kg of weight. bodily.
The sodium brought by the integration of bicarbonate makes it unsuitable for the treatment of sportsmen and athletes suffering from arterial hypertension.
3) Calcium carbonate
Calcium carbonate (-CaCO3-) is a product mostly used in the treatment of stomach acid, as it boasts a longer gastric stay (albeit slightly) than sodium bicarbonate; its metabolic efficacy is however comparable to that mentioned above but prolonged consumption can negatively affect intestinal peristalsis causing constipation.
4) Magnesium hydrate and aluminum hydrate
Also the "magnesium hydrate [Mg (OH) 2] and the aluminum hydrate [Al (OH) 3] are weak bases used as antacids, but while boasting greater therapeutic characteristics, their intake does not significantly alter the quantity of blood bicarbonate; therefore, their use for sports purposes is not comparable to that of sodium bicarbonate.
5) Carnosine
Carnosine is a dipeptide formed by B-alanine and histidine; its therapeutic use is basically PRO-healing but in the sports field injections of liquid carnosine are administered to improve maximum performance. It seems that carnosine is one of the most effective remedies against the accumulation of lactic acid by increasing resistance and improving the overall work capacity. Carnosine is able to buffer lactic acid thanks to the "intervention of histidine, while the" alanine is used as a neoglucogenic substrate.
The oral intake of carnosine must be carried out a few hours before the performance and the intake doses are between 50 and 1000mg / day.
Bibliography:
- Recommended Nutrient Intake Levels for the Italian Population (LARN) - Italian Society of Human Nutrition (SINU)
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