Investigation of circadian rhythms in peak power and mean power of female physical education students.

The aim of this investigation was to establish if there were characteristic circadian rhythms in peak power and mean power. Thirteen female physical education undergraduate students, aged from 18-21 years, were measured for peak power and mean power (Wingate Anaerobic Test) at four time points: 0300, 0900, 1500, and 2100 hours. Peak power was defined as the highest mechanical power that is elicited during a 5-sec period and mean power was defined as the average power that is sustained throughout a 30-s period. A significant circadian rhythm was found for the peak power (F = 3.22, p = 0.030). The mean peak power at 1500 h was about 7% higher (p < .05) than at 0300 h. Also a tendency to circadian rhythm was observed in mean power (F = 3.99, p = 0.01) being about 16% and 15% higher respectively (p < 0.05) at 1500 h and 2100 h than at 0300 h. Based upon the particular protocol used, it was concluded that there are characteristic circadian rhythms in peak power and mean power.