Abstract
The purpose of the present study was to determine the time-of-day effects in maximal anaerobic power and capacity and in blood lactate responses during and after a supramaximal exercise. Fourteen undergraduate male students participated in the Wingate Test at three time points: 09:00, 13:00 and 17:00 hours on separate days. Before each test subjects' body weight, oral temperature and resting heart rate and subjects' peak power and mean power during the Wingate test were determined. Blood lactate concentrations were determined before, immediately after and at 3rd, 5th and 7th min of passive recovery period. A significant circadian rhythm was found for oral temperature(p<0.001) and for peak (p<0.05) and mean (p<0.05) powers respectively. No significant circadian variation was observed for body weight, resting heart rate and blood lactate concentrations between all measured time units(p>0.05). It is concluded that a time-of-day effect was evident in maximal anaerobic power and capacity however this variation was not parallel with those of oral temperature. In addition a time-of-day effect did not exist for the blood lactate concentrations.