Hysteresis of changes in physiological indices during physical workload and recovery of football players during exercise stress test

Abstract

Owing to their high degree of safety and cheapness exercise stress tests are used widely in sport medicine. Adaptation mechanisms of the cardiovascular system of top athletes have not been studied sufficiently yet and new methods of the data registered during the process of performing physical workload and recovery acquire particular importance. Even having made use of the newest mathematical methods it is by no means easy to embrace and comprehend a tremendous lot of phenomena lying at the bottom of this problem because of its extreme complexity and intricate interrelationships. Methods of non-linear analysis and the new methodology of research increase the possibilities of knowledge of the function(s) of the human body and allow one to discern still unravelled properties and use them in evaluating functional condition. The hypothesis of the present research was formulated taking into account the fact that the indices, that characterize the functional condition of the cardiovascular system of football players, differ from those of non-athletes. The analysis of hysteresis of physiological indices includes the assessment of processes in operation during physical workload and recovery, as well as reflects the ratio of recruitment and inhibition processes taking place in the human body. The sample of the subjects embraced 55 men football players, 32 men non-athletes. ,,Kaunas – krûvis“, an automatized analysis system, created at the Institute of Cardiology of Kaunas University of Medicine, that is capable of both registering and analyzing the power developed by the subject and 12-leads of ECG synchronically has been used for evaluating the functional condition of the cardiovascular system. All the subjects did a computerized bicycle exercise stress test. A short-term provocative research protocol was used. Prior to the workload applied, throughout bicycle exercise stress test and during the period of recovery (5 min) the following indices – heart rate (H.