Adaptive changes in the circulatory and respiratory systems under the influence of winter football training were studied. 50 men aged 21-25 years — 3rd-4th year students — were examined: control group — 25 people specializing in “soccer” (S), main group — 25 people studying in the specialization “winter football” (WF). The examination was performed twice — before and after physical activity. Running (average pace, 180 steps/min) for 15 minutes was used as dosed physical activity. The loads were performed either indoors at a temperature of plus 22–24°C, or in winter outside at a temperature of minus 18–20°C. Indoor and outdoor surveys were carried out on different days. Assessment of peripheral blood flow in the lower extremities was performed using rheography; to assess the main blood flow in the femoral artery, Doppler ultrasound was used. The study of external respiration functions was carried out using pneumotachography. The lactate concentration in capillary blood was determined photometrically. It has been shown that physical activity performed in the cold in adapted athletes (WF group) promotes increased integration between the respiratory and circulatory systems, ensuring the formation of a functional system characterized by stronger connections for optimal adaptation to the combined effects of physical activity and cold. In athletes training indoors (group S) under conditions of a combination of physical activity and cold exposure, on the contrary, desynchronization of the interaction of the respiratory and circulatory systems occurs, which leads to a decrease in adaptive reserves. Thus, sports training in winter football triggers phenotypic adaptive changes and creates a number of physiological mechanisms that promote increased integration between the respiratory and circulatory systems, providing optimal adaptation to the combined effects of physical activity and cold. The obtained facts will be useful for the development of special training programs aimed at increasing the functional reserve of the cardiorespiratory system of athletes training in cold conditions.