Exercise effect on the circadian rhythm of left ventricular systole in healthy men with higher and lower physical fitness.

The purpose of the present work was to investigate the effect of exercise on the diurnal changes of electromechanical systolic time (QS2) in healthy men with different physical fitness (N = 20, PWC150-804.3 +/- 114.6 kpm/min), and with higher (N = 12, PWC150-881.3 +/- 71.8 kpm/min) and lower (N = 8, PWC150-688.8 +/- 46.0 kpm/min) physical fitness. The study on 20 male volunteers aged 19-21 at 6 times of 24-hours period in intervals (4-hours) was performed. The policardiograms according to Blumberger at rest and after 10 minutes of exercise were obtained. The individual level of exercise at test PWC150 was determined. The values of QS2 from policardiograms according to Weissler's method were read and for heart rate were corrected. The mathematical analysis by the method of Halberg was made. It was found that in healthy men at rest the circadian rhythm of QS2 existed. The effect of exercise on the circadian rhythm of QS2 was dependent on level of physical fitness. After exercise in human with higher physical fitness the circadian rhythm of QS2 was presented, whereas in human with lower physical fitness it was not evident.