Abstract
The purpose of this investigation was to assess the effects of different active warm-up (AWU) durations on the diurnal variations of temperature and power output during the Wingate test. Eleven physical education students underwent the Wingate test at 08:00 and 18:00 h after four AWU protocols: control warm-up (CWU), 5 min (AWU
5
), 15 min (AWU
15
), and 20 min (AWU
20
). The CWU consisted of 5 min of free pedaling; however, the AWU
5
, AWU
15
, and the AWU
20
protocols consisted of pedaling at a constant pace of 60 rpm against at 50% of the maximal aerobic power. Oral temperature was recorded at rest, at the end of warm-up, and before and after the Wingate test. The temperature has improved significantly from morning to evening. However, the increase was greater after AWU
15
and AWU
20
. The power peak and the power means were significantly higher in the evening in comparison with morning. These diurnal variations persisted after all AWU durations. However, the increase was greater in the morning and in the evening following the AWU
15
in comparison with the AWU
5
and the AWU
20
. The fatigue index (FI) recorded in the evening is statistically higher in comparison with those recorded in the morning. In addition, our findings show an effect of the AWU durations on the FI. In moderate conditions, an AWU of 15 min at 50% of the maximal aerobic power is the best duration for the improvement of both core temperature and muscle power in the morning and in the evening.