Comparison of cardiovascular resistance to orthostas in athletes with different level of physical performance
The aim of the study was to investigate the resistance of the central and peripheral haemodynamics to tilt-test in athletes (n = 30) with different levels of physical performance (PWC <sub>170</sub>). Cardiac output and regional blood volume in the upper and lower extremities, abdominal and neck regions were determined simultaneously by the impedance method. We found that in athletes with a higher PWC <sub>170</sub> despite the pronounced decrease of cardiac output in response to the tilt-test, distribution of blood flow in the neck region direction was higher and due to an increase of blood flow in the neck region and to an decrease in the legs. Increased efficiency of the distribution of peripheral blood flow may be one of the mechanisms of orthostatic tolerance in the athletes, who develop endurance.