Abstract des Autors

The aim of this study is to consider whether apnea or other factors, like: facial immersion, body position, training, or exercise difficulty, play an important role on the diving reflex (DR) induced bradycardia. In six synchronized swimmers of the same team, competitors at the Italian Synchronized Swimming Championship, the heart rate (HR) was recorded by a beat to beat water proof heart rate recorder. Four competitive figures have been considered and the data recorded during apnea have been compared with the ones recorded while the athletes were breathing air from a tank. During all the performances with a tank, the heart rate variations show a constant increase in the cardiac frequency from the beginning till the end of the exercise. Only on facial emersion in front layout position, and not in back layout position, was there a decrease in the HR and this report is in contrast with the literature. The authors conclude that during synchronized swimming: the apnea itself is the most important reflex inducing bradycardia; the facial immersion does not cause a bradycardia: the facial emersion in front layout position or in back layout position produce a different control over HR. Verf.-Referat