Are maximum heart rate and recovery heart rate of cyclists influenced by the time of the day?

Abstract

Only a few studies have investigated the influence of biological rhythm in maximum heart rate (HR max) and recovery heart rate (HRrec) of cyclists. The aim of this study was to determine if the time of the day has an influence on HR max and HRrec of cyclists. Eight cyclists (mean age, 37.9 yrs) performed a progressive cycle ergometer tests in the morning and in the evening periods with an initial load of 15 W that was increased 30 W every 2 min at a pace of 80 to 90 rev·min-1. Body temperature (BT), HR max and HRrec were analyzed with the Shapiro Wilk W test to verify the normality of the data. Differences between the two exercise periods were analyzed by the Student’s t test (P≤0.05). There was no significant difference between HR max and HRrec in the two exercise periods. The findings indicate that there was no interference of the time of the day on the cyclists’ HR max and HRrec.