The main risk factors for the syndrome of overtraining in athletes can be grouped as follows:
- undiagnosed diseases and pathological conditions;
- physiological stress factors: repeated change of time zones, un dosed use of additional adaptation factors (high mountains, hypoxic training in laboratory conditions), training in high or low temperatures, polluted air, domestic and professional intoxications;
- hygienic factors: a) nutritional (negative energy balance, insufficient intake of carbohydrates and/or proteins, iron deficiency, magnesium deficiency, etc.), b) violation of the drinking regime – chronic fluid deficiency, c) violation of the regime (lack of sleep, drinking alcohol, smoking, etc.);
- side effects of pharmacological drugs;
- stressful psychological factors (increased expectations from the coach or family members, prolonged competitive stress, personality structure features, poor social environment, poor relationships with family and friends, personal or emotional problems, as well as additional requirements related to school or work);
- errors in the organization and content of the training process;
complete disregard for current biomedical control.
In addition to the factors listed above, one should not forget about the possible side effects of pharmacology. The pharmacological risk factors for the syndrome of overtraining in athletes are primarily (paradoxically) the side effects of drugs, which, presumably, can improve the tolerance of training loads. These include:
- antioxidants – reduce the formation of toxic metabolites during intense muscle activity;
- antihypoxants – reduce the damaging effect of these metabolites;
substrate antihypoxants (creatine, neoton) – increase the intracellular creatine fund;
- nootropics – increase brain resistance to various harmful effects (hypoxia, intoxication, lowering or increasing temperature, etc.), improve specific hemorheological parameters, normalize impaired cerebral circulation in the absence of a direct effect on blood vessels and the accompanying psychotropic effects;
- plant adaptogens – activate stress-limiting systems.
What is the reason for this point of view? First of all, with the fact that all stimulators of health are aimed at overcoming a certain “mobilization threshold” of health reserves, which is a mechanism that protects against overload and helps maintain homeostasis of the body. When they succeed, the body subsequently responds to stimulation with a phase of reduced resistance, since each “overcoming” has its own physiological “price”, which, sooner or later, must be paid. As for individual groups of drugs, here, first of all, the prolonged uncontrolled use of antioxidants is of concern.
Taking antioxidant supplements can increase the degree of oxidative stress in humans. As a rule, in this case, there are by-products of fat peroxidation. The effectiveness of antioxidants can change during the long-term process of lipid peroxidation in liposomes. In one of the scientific studies, ionol, quercetin retinol acetate, ergocalciferol glutathione (reduced form), unithiol taurine, succinic (sodium succinate), tartaric (potassium-sodium tartate), and citric (sodium citrate) acids were analyzed as antioxidants. It was found that almost all of the above funds at a certain stage of stress can behave as prooxidants. The only exception was citrate, in which in no case was a significant prooxidant effect detected. In general, the following conclusion was made: the effectiveness of the studied pharmacologically active substances with an antioxidant effect changes significantly during the long-term process of lipid peroxidation in liposomes and depends on the chemical nature of the antioxidant, its concentration, and intensity of lipid peroxidation, specified by the method of initiation of liposome oxidation.
In this vein, I would also like to mention the work on a possible decrease in the background of taking antioxidant supplements of mitochondrial biogenesis in skeletal muscle. Physical activity increases the production of reactive oxygen species in skeletal muscle, and athletes often use antioxidant supplements in the hope that they will weaken muscle damage caused by reactive oxygen species and relieve fatigue. However, an increasing amount of data indicates that active oxygen forms formed during intense exercise are involved in the regulation of cellular signaling and contribute to the adaptation and regeneration of muscles after intense exercise. Antioxidants inhibit the formation of reactive oxygen species in muscles and weaken the processes of intracellular signaling, which are important for muscle adaptation during exercise. Exercise increases the expression of genes that are significant for mitochondrial biogenesis, and antioxidants block this increase. Although these facts are already known, it remained unclear whether antioxidants reduce mitochondrial biogenesis only under exertion, or do they affect basic mitochondrial biogenesis. Plant adaptogens deserve special consideration.
Unreasonably large doses of adaptogens lead to reduced results. This may be due to the excitation of the sympathoadrenal system (perversion of the effect), as well as the ability of antioxidants in large doses to provoke free radical oxidation. They exhibit synergism with natural antioxidants, which can lead to an excessively strong manifestation of the antioxidant effect and provocation of lipid peroxidation.
Even an overdose of vitamins can cause a decrease in the performance of athletes. We are talking primarily about vitamin C, the prolonged use of high doses of which can lead to a sharp decrease in the permeability of capillaries of the histohematological barriers and, consequently, to a deterioration in the nutrition of tissues and organs, an increase in the basal metabolic rate, a change in hematological parameters, impaired myocardial trophism, and a worsening of neuromuscular muscle transmission. With prolonged use of large doses of vitamin C, excitation of the central nervous system (anxiety, feeling of heat, insomnia), the formation of calcium and urate stones in the kidneys, and increased blood coagulation are possible. Hyper doses of vitamin C also leads to an increase in the loss of vitamins B12, B6, and B2 from the body. Given that the “boundaries of pharmacological support” of athletes are becoming wider, the problem of risk factors of a pharmacological nature is becoming increasingly relevant, including when it comes to the occurrence of overtraining syndrome.