Surfing in urban water bodies in winter: the physiology of extreme adaptation and urban anthropology Introduction: Ice urban extreme as a scientific phenomenon Winter surfing in urban water bodies, whether it be non-freezing sections of rivers, city beaches, or specially equipped areas, is a complex phenomenon at the intersection of sports physiology, psychology of extreme behavior, and urban sociology. It is not just a type of water sport, but a practice that challenges fundamental adaptive mechanisms of the human body and transforms the perception of urban space. Participants in this movement (surfers-«sea lions», or ice surfers) voluntarily subject themselves to water temperatures close to 0°C, which triggers a cascade of neuroendocrine and cardiovascular reactions, the study of which is of significant interest to science. Physiology of cold shock and adaptation: what happens to the body? Diving into icy water is a powerful stress factor that causes a sequence of reactions: Immediate cold shock (first 1-3 minutes): Unconscious hyperventilation: A sharp intake of breath followed by uncontrollable rapid breathing. This is a reaction to the stimulation of cold receptors in the skin, sending signals to the respiratory center in the medulla oblongata. Tachycardia and vasoconstriction: The heart rate may instantly jump by 50-100%. There is a sudden constriction of peripheral vessels (hands, feet, skin) to reduce heat loss and maintain blood supply to vital organs. Blood pressure sharply increases. Catecholamine release: Adrenaline and norepinephrine are released into the blood in huge quantities, preparing the body for the "fight or flight" response. Phase of short-term adaptation (after 3-5 minutes): Activation of brown fat: In trained individuals, brown fat tissue (especially in young people) is activated, which has a unique ability for non-shivering thermogenesis — producing heat through the oxidation of fatty acids. Cortisol and endorphin release: Prolonged ... Читать далее