Some aspects of the influence of extreme climatic factors on the physical performance of athletes

Professional athletes often have to participate in competitions in climatic conditions that differ from the optimal or habitual ones for their place of residence. In this regard, it seems relevant to the question of how borderline and extreme external conditions (low and high ambient temperatures, changes in atmospheric pressure, altitude) affect sports performance and endurance. The review presents the biochemical mechanisms underlying the adaptation of athletes to environmental conditions. The human body maintains a fairly constant internal temperature (in some articles — the core) of the body at a level of 37 ± 10C throughout its life, despite a wide range of environmental parameters. The intensity of the processes providing for the release of heat is reflexively regulated. The neurons responsible for heat exchange are located in the center of thermoregulation of the hypothalamus. In the course of evolution, mammals have developed a variety of mechanisms for regulating body temperature, including nervous and humoral, that affect energy metabolism and behavioral responses. There are two ways of heat generation: contractile thermogenesis, due to contractions of skeletal muscles (a special case — cold muscle tremors), and non-contractile — when the processes of cellular metabolism are activated: lipolysis (in particular, brown adipose tissue) and glycolysis. When exposed to extreme ambient temperatures, the thermoregulatory system adjusts to maintain a stable core body temperature by preventing heat loss and increasing heat production in cold conditions, or increasing heat dissipation if the ambient temperature rises. The ambient temperature corresponding to 20–25 ºС on land and 30–35 ºС in water is considered thermoneutral for humans in a state of relative rest. However, any deviations from these conditions, especially against the background of intense physical exercise, can lead to functional overstrain, decreased endurance and sports performance.