Šio darbo tikslas – nustatyti, ar didelės apimties koncentruoti jėgos greitumo krūviai gali pakeisti širdies ir kraujagyslių sistemos funkcinių rodiklių atsigavimo eiliškumą. Tyrime dalyvavo 17 didelio meistriškumo sportininkų, t. y. Lietuvos nacionalinių rinktinių nariai ir kandidatai, kultivuojantys dvikovos sporto šakas (graikų-romėnų imtynes, dziudo, boksą). Kiekvienam tiriamajam jo treneris sudarė individualią ribinio sunkumo treniruotės etapo programą: jėgos greitumui lavinti mezociklo pratybose buvo planuojami didelės apimties koncentruoti jėgos greitumo fiziniai krūviai. Pirmasis tyrimas buvo atliktas prieš, o antrasis – kitą dieną po treniruotės mezociklo pratybų. Atsigavimo proceso ypatybėms vertinti buvo naudojama EKG registravimo ir analizės kompiuteriø programa „Kaunas-krūvis“ – registruojama 12 standartinių derivacijų EKG ir matuojama arterinio kraujo spaudimo kaita Rufjė fizinio krūvio mėginio ir 30 s trukmės vertikalių šuolių testo metu bei atsigavimo procese. Tyrimo rezultatai parodė, kad tiek po Rufjė fizinio krūvio mėginio, tiek po 30 s vertikalių šuolių testo greičiausiai atsigauna JT/RR rodiklis, po jo – ŠSD ir ilgiausiai užtrunka JT intervalo atsigavimas. Iš kraujo spaudimo rodiklių greičiau atsigauna sistolinis, lėčiau – santykinis kraujo spaudimas. Daroma išvada, kad reikšminga atsigavimo po fizinių krūvių ypatybė yra atitinkamas širdies ir kraujagyslių sistemos funkcinių rodiklių atsigavimo nuoseklumas. Esant normaliai funkcinei būklei, pirmiausia sunormalėja santykis tarp reguliacinių ir aprūpinimo sistemų, tada atsigauna reguliacinių ir vėliausiai – aprūpinimo sistemų rodikliai. Mezociklo pratybose taikomi koncentruoti didelės apimties jėgos greitumo fiziniai krūviai neturėtų paveikti rodiklių atsigavimo eiliškumo, o atvejai, kai registruojami atsigavimo procesų eiliškumo pasikeitimai, matyt, turi būti vertinami kaip per didelių krūvių efektas.

It have been establishes that, although single muscular contraction power have been increasing during the testing period, results were not high enough because of too low jumps and too low speed of take-of. Thus we may assume that individual players' adaptation during all the season have not beet oriented at the increasing of above capacities. Indices of short-term loads capacities, as anaerobic alactic muscular power, 5 m running velocity and agility, were increasing, and their results were close to the indices of high performance basketball players. Psychomotor response rate and movement frequency increased during the testing period in average 15,92 ms. During the four year period, functional capacity of circulatory and respiratory systems was of good adaptation level. Roufier index does not exceed 5,42 and was not lower than 3,80. Heart rate at rest (reacting at the physical loads and recovering after) in four years changed slightly.

The development of rowing in Lithuania has been with varying degrees of success from periods of high performance to low achievements and vice versa. The sport science has been gaining an increasing role in the training of high performance athletes. The problems faced in rowers’ training are analysed by a big number of scientists from various countries (Hagerman, 1988; Steinaker, 1993; Yoshiga, Higuchi, 2003). The challenges of high performance athlete training and difficulties encountered working with rowers have been also discussed by Lithuanian scientists (Raslanas, 1998; Štaras, Arelis, Venslovaitė, 2001; Skernevičius and others, 2004). Not to stand behind the scientific progress, the research in the process of rowers’ training is becoming of urgent importance. The object of the research is training of Lithuanian national rowing team and its members’ fitness. The goal of the research is to investigate physical development, physical fitness, abilities, functional capacity of athletes in Lithuanian national rowing team and to highlight features in training and fitness of an athlete with particularly high sport performance achievements. The sample of the research included 10 candidates of Lithuanian national rowing team. Lately one of them has demonstrated very high performance results. The athlete’s training in the four-year Olympic cycle, the athlete’s diary and generalised reports of the coach as well as competitive performance were analysed. The process of athlete’s body adaptation to physical loads was investigated (Skernevičius et al, 2004). Though during the four-year Olympic cycle the physical loads volume in the training of high performance young athlete showed an upward tendency, the physical load in the fourth year was not intensive and may be increased.[...]

The article notes that the development of oxidative stress and the violation of cellular energy balance is the primary link of the vast majority of systemically-forming homeostatic shifts in the athlete’s body and changes the vital structure and function of cellular and subcellular proteins membrane. Changes in the quantitative and qualitative composition of lipid components of membranes, inhibition of the activity of key glycolysis enzymes, as well as the deterioration of bioenergy mechanisms, result from the accumulation of free radicals due to activation of lipid peroxidation. The protection of the organelles responsible for energy supply from oxidative effects is provided by mitochondrial disconnecting proteins that exist in the myocardium. The development of metabolic ischemia due to the imbalance between the delivery of oxygen to cardiomyocytes and their need for myocardium is accompanied firstly by the inhibition of the process of oxidation of glucose and an increase in the use of fatty acids, and then the accumulation of lactate with the development of acidosis of the intracellular environment and the impairment of the ability of myocytes and cardiomyocytes to relaxtion and contraction. It has been established that strenuous muscle activity leads to the formation of a hypoxic state with its characteristic redistribution and increase of energy, metabolic, structural resources of the body in the interests of the tissue where adaptive adjustments are taking place. The insufficiency of energy generation due to the development of this state leads to the dysfunction of the mitochondrial apparatus, which subsequently causes the violation of the energy supply, antioxidant protection, membrane stability due to intensification of lipid peroxidation and leads to cell apoptosis. This forms a background for the occurrence of fatigue and tension, followed by reduction of physical performance of athletes. The detection of the above changes makes it possible to prevent and correct in a timely manner the negative effects of oxidative stress associated with ultra-intensive physical loads.

At present time, the rational search for a protection of cardiovascular system of athletes and the assessment of such protection efficiency are the very important problems in sports pharmacology and sports cardiology. It is worth noting that athletic training pharmacology, aimed at the stimulation of physical workability in the majority of sports events, can become, together with overloads, the principal reason for a deterioration of health and life’s quality as well as for the sudden death of athletes without a proper cardioprotection. The problem of protection is significantly complicated under modern conditions due to the permanent hardening of anti-doping sanctions (e.g., the recent ban on the use of trimetazidine and meldonium) that essentially limit the possibilities for sports cardiologists. Therefore, the most grounded exit, from the current position, is the use of metabolitotropic medications, in particular, those on the basis of L-carnitine (gamma-butyrobetaine). The wide spectrum of physiologic and biochemical influence of this substance on organism gives possibility to moderately affect the physical and mental workability of athletes even under the conditions of long-term intense physical loads. The complex action of pharmacological agents on the basis of L-carnitine on organism allows one to use it on all stages of the preparation with high efficiency of the cardioprotective and ergogenic effects. Despite the bans of WADA, sports cardiologist possesses a sufficient pool of pharmacological agents that can ensure the protection of myocardium under conditions of training process and competition and can preserve athlete’s health as well as his/her physical workability.

Both specific and nonspecific metabolic transformations, occurring in the body of athlete under intensive and prolonged physical loads, have been characterized in the review paper. It has been emphasized that oxidative stress, which belongs to general pathogenic factors of further myocardium pathology formation, and load induced hypoxia, which is later associated with tissue hypoxia of metabolic origin, represent the initial link of subsequent homeostatic balance changes. Changes in the activity of creatine phosphokinase-MB fraction, content of cardiac troponins I and T as well as terminal natriuretic peptides are referred to specific markers of myocardium strain. Wider range of myocardium strain nonspecific markers includes both alterations of lipid metabolism and numerous, oxidative stress mediated, metabolic changes at the level of cellular and subcellular membranes of cardiomyocytes, followed by changes in the activity of membrane-bound enzymes and lysosomal proteinase ejection first into extracellular matrix and then – into circulatory bed as well as erythrocyte membranes and their ATP content that are accompanied by deterioration of blood oxygen transport function. The above mentioned negatively influences myocardial contractility and leads to the development of hypertrophic cardiomyopathy. Identification of the markers of athlete heart strain allows timely to be corrected by pharmacological means, aimed at normalization of metabolic disorders and prevention of myocardial hypertrophy, which is the major cause of sudden coronary death among athletes.