Abstract des Autors

Heart rate rhythmicity at about 0,1 Hz and 0,25 Hz was studied in canoeists during physical rest and with increasing physical work loads to gain information about the cardiac autonomic balance at different levels of central nervous activity. Both heart rate parameters showed a characteristic time course during a 44-min rest. The pre-start 0,25 Hz rhythmicity was 35% lower and the 0,1 Hz rhythmicity 22% lower than during physical rest. With a 30 W work load, the rhythmicity had already fallen by 91% and 52%, respectively. At 110 W it had almost completely disappeared. In conclusion, physical rest represents a nonstationary state. With increasing acticity, the diminuation in heart rate rhythmicity is caused primarily by a withdrawal of parasympathetic heart rate control. Verf.-Referat