This study sought to understand whether night sleep quality is affected by fatiguing physical activity (PA) when conducted early or late in the evening. 9 males (18–38yrs) performed sessions of fatiguing–PA over 3 consecutive days (Mon–Wed), for 2 weeks. One week the PA was performed at 17h, and in the other week at 21h. A Control–week included no PA (PA ABSENT ). The fatiguing–PA sessions comprised several sets of the 20m Shuttle–Run–Test (20mSRT). Sleep was assessed by actigraphic recordings obtained over 3 nights each week. It included the nights following the PA–sessions and the same days in the week of PA ABSENT . Sleep–quality perception was evaluated by means of the National Sleep Foundation–Sleep Diary. The heart–rate (HR) and body–temperature (BT) at bed–time and waking–up were registered as well. Neither the 20mSTR–estimated VO 2max nor the number of maximal 20mSRT sets were different in the PA 17h and PA 21h sessions. Compared to the PA ABSENT , the PA 17h and PA 21h sessions increased the HR at bedtime, which recovered to baseline level after the night of sleep. BT was also reduced when waking up compared to bed time, but this was also observed in PA ABSENT . Sleep parameters measured by means of actigraphy were not modified by fatiguing activity when compared to PA ABSENT. Nevertheless, the subjective perception of sleep–quality was detrimentally affected by fatiguing PA.
Performing fatiguing PA early or late in the evening had no affect on objective sleep quality but, subjectively, a deterioration of sleep quality was perceived by the participants.