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.

The purpose of this study was to investigate the effects of the lack of oxygen on an organism’s functionality in the low season preparation term within the cycling stage of triathlon. This study might be applied to many different sports. “Oxygen intake”, “Hypoxia”, “Respiratory muscles training” are very well known terms in sports. Methods: nine healthy active triathletes (males n = 9), age (20 ± 7 years). All subjects were competitive at national and international level. All were trained in the equal conditions using Spinning bikes in the same room (22 °C ± 2.4 °C and 82 ± 4% RH), at the same time, at thesame cadence (100 revolutions ± 5 rev.) and performing the same exercises. All participants had 4 monocycles pre-experimental preparation (PP), followed by 12 monocycles (hypoxia training – HT) as a part of a monthly microcycle. During a 60 min session one group was using Ultrabreathe, another group was using the Elevation Mask 2.0 and the last group didn’t use any device performing as a control group, then another 4 monocycles for recovery (R). Data was collected at the end of each phase-PP (4 monocycles in one week), in the middle and at the end of phase-HT (8-monocycles using Elevation Mask 2.0 and Ultrabreathe devices) and the end of phase-R (4-monocycles with no respiration effort). Maximal oxygen consumption (VO2max), Lactate (LA), cadence power (W) and heart rate (HR) was recorded and collected as part of the research. All were measured in laboratory conditions using KORR CardioCoach gas analyzing system for VO2max, cadence power was measured by the Monark LC4R ergometer bike, whereas blood samples were collected for lactate using the COBAS Accutrend Plus device, heart rate data was measured by the POLAR H7 heart rate belts and POLAR Power Flow system. The performances expressed changes in all four parameters on all stages of the experiment. Maximal oxygen consumption showed an increase in two groups who were using the respiratory depression devices after 8 monocycles – by 4.35 and 3.01% respectively, and by the end of the experiment the total difference was – 3.74 and 0.82% respectively. Improvements were also defined in the level of increase in lactate and maximum cadence power. There was a power increase in the two groups who were using the respiratory depression devices after 8 monocycles – 3.92 and 1.57% respectively, and by the end of experiment the total difference was – 3.57 and 0.87% respectively. All this data shows us the positive effects of hypoxial training, what might prove a useful tool for increasing endurance and, meanwhile, it might positively affect the final competition results. HT might be used for pulmonary function increase, increase of the respiratory muscles strength and body adaptation against stress created by hypoxial conditions during a race.