Muscle catabolism is a mainly induced phenomenon:
- from malnutrition (as occurs in the Third World or in the case of eating disorders - DCA)
- from alcoholism
- from some chronic diseases
- from sporting practice NOT properly supported by nutrition.
NB. the presence of over-training can also contribute.
In some EXCESSIVELY protracted and / or intense sports performances (marathon, march, triathlon-iron man, cycling tour, etc.) muscle catabolism (usually appropriately compensated by recovery, i.e. by anabolic hormones + nutritional molecules) can also be excessively activated in conditions of eunutrition and / or adequate rest.
Muscle catabolism therefore represents an undesirable effect of tissue turnover, characterized by an evident imbalance between the demolition of the plastic structures of the muscle and consequent restoration or supercompensation.
Although having different etiological causes (and severity), muscle catabolism ALWAYS occurs through the same process: insufficiency of glucose in the tissues as an essential energy substrate for cellular respiration; moreover, that the sugar deficit only affects the muscles recruited in the athletic gesture or the entire human machine (as occurs in some unbalanced diets, in the caloric / protein malnutrition of the less well-off populations, in some DCAs, in alcoholism or, even worse, in complicated liver cirrhosis), an impairment of glycaemia will still be obtained in the medium to long term.
We remind you that carbohydrates, defined as NOT essential because they can be synthesized through hepatic neoglucogenesis, are in fact NECESSARY for survival and decisive for the success of sports performance, both aerobic and anaerobic (read the article: Hunger crisis during sport).
During exercise, lack of them can cause:
- An increase in the oxidation of amino acids in food proteins which, if used for energy production, CANNOT fulfill the plastic requirements (unless they are present in excess in the diet, but in this case it would be necessary to take into account the side effects of a high-protein diet)
- An increase in muscle proteolysis resulting from the exhaustion of:
- fasting liver glycogen
- hepatic and muscle glycogen during exercise.
BOTH THESE CASES DETERMINE MUSCLE CATABOLISM, BOTH BY DIRECT OXIDATION OF THE BRANCHED AMINO ACIDS AND BY NEOGLUCOGENESIS OF THE OTHER TISSUE PROTEIN BRICKS.
NB. If muscle catabolism has as its primary etiological cause the NON-compensated sporting activity, the tissues primarily and mainly involved are those assigned to the specific athletic gesture (eg the legs of the cyclist or marathon runner).
Muscle catabolism in sport
Ultimately, the sportsman's muscle catabolism occurs mainly due to the imbalance between motor activity on the one hand and nutrition + rest on the other. In reality, the topic would be very vast, multifaceted and rich in insights, therefore it is not possible to summarize it exhaustively in these few lines; on the other hand, the objective of the article is to direct readers towards a greater awareness of the phenomenon ... and above all to avoid the possibility that they will suffer the fishing commercial of the major producers of food supplements.
Why should an athlete in good health have muscle catabolism?
It is not as frequent as one might believe but it is still possible; the most evident case concerns the lovers of the body, who pursue the goal of exalt muscle mass consequently reducing the fat adipose mass (called definition or cutting phase). Often these subjects incur muscle catabolism due to the unification of physical exercise (promiscuous, both anaerobic and aerobic) to a low-carb diet, perhaps ketogenic and in any case high-protein. In this case, the diet that is not adequately rich in carbohydrates (NECESSARY in "PROLONGED muscle exercise) determines the depletion of glycogen reserves and the consequent hypoglycemia; in such stressful conditions, the body reacts by releasing some specific catabolic hormones (glucagon, various catecholamines and, often, cortisol as well) which facilitate both lipolysis and muscle protein catabolism. On the other hand, a bodybuilder who pursues the goal regardless of aerobic activity and carefully choosing the muscle-building chart, will significantly reduce the onset of muscle catabolism; in this case, the anabolic stimulus induced by the muscle exercise (appropriately compensated by the right recovery times) is "almost always" sufficient to guarantee a stasis (maintenance) of the hypertrophy even in concomitance with a low-sugar diet (variable mainly based on subjectivity).
Another fairly frequent case is that of vegan sportsmen (non-vegetarians); who follows a diet totally devoid of foods and ingredients of animal origin or derivation, it often does not introduce a protein quantity sufficient to guarantee the correct up-take of the essential plastic amino acids of the tissue proteins. In this situation, muscle catabolism is induced by a "PROPORTIONALLY hypo-protein diet, or better, by a diet lacking in peptides of high biological value. Obviously, we are talking about sportsmen and not sedentaries who, fortunately, can maintain a good state of health respecting protein coefficients equal to 0.75g / kg of physiological weight (commonly complied with by a well-calibrated vegan diet). Ultimately, the vegan diet is a diet that hardly meets the needs of an athlete with high goals, both in body-building, both in competitive sports activities.
How to avoid / compensate for muscle catabolism
Avoiding muscle catabolism is not difficult, it would be enough to respect a balanced diet and weighted on specific physical-sporting activity. Each discipline requires energy costs and mixtures of well-defined substrates, which is why (in the search for performance maximization or in slimming / definition muscle) requires the intervention of a nutrition specialist; it is certainly not an essential requirement ... but it often makes the difference!
Can the use of food supplements limit muscle catabolism?
Obviously, in the presence of a NOT balanced diet, every saint helps!
On the other hand, it doesn't make much sense to take food supplements when you "tighten your belt at the table" ... but it seems that corporate marketing has managed to convince several consumers that: a simple over-the-counter product can, not only replace food , but even exceed them in quality and nutritional richness. Personally I believe that muscle catabolism in sports activity is INEXORABLE within percentages of 2-4% of the total energy cost but, with a correct diet combined with a correct recovery, it is possible to drastically limit the use of food supplements. Obviously, for an athlete of elite who practices at least 15 hours of weekly training, the "bugbear" of muscle catabolism presents itself with greater firmness and importance; in this case, both for the body and for the mind (since self-suggestion is a determining phenomenon), the use of malto-dextrin supplements (carbohydrates) and branched-chain amino acids (BCAAs) can be absolutely profitable.
Nonetheless, the statistics state that most of the athletes who supplement (various products: proteins, BCAAs, maltodextrins, essential AAs, arginine, glutamine, creatine, etc.) do not obtain any appreciable benefit since, as reiterated, a "balanced diet , balanced and associated with the right rest is almost always more than enough to prevent and compensate for muscle catabolism induced by intense and prolonged physical exercise.
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