The influence of various forms of one-time physical activity at -5°C on the rheological properties of blood in young men.

Physical activity combined with low temperatures can improve physical fitness, the efficiency of many organ systems, and mental well-being. The study investigated the effects of single sessions of various forms of physical activity (running, walking, lying down) conducted in a thermal climate chamber at a temperature of -5°C on blood rheological properties in young men. The participants (21 men aged 22 years), when performing the activities, were fasting and hydrated with 500 ml of water. Erythrocyte deformability increased at a shear stress of 4.24 Pa in the walking group and in the jogging group between the measurements before and after the activity. An increase in erythrocyte deformability was also recorded at a shear stress of 8.23 Pa, 15.95 Pa, 30.94 Pa, and 60.00 Pa after running, walking, and lying down compared with the blood indicators measured before these activities. Statistically significant changes were reported for aggregation index in the jogging group after the activity. The increase in erythrocyte deformability at higher shear stress levels may constitute a mechanism to facilitate blood flow in men exposed to a temperature of -5°C. The study revealed specific differences that can be used to combine cold therapy with physical exercise.