Abstract
Daytime physical activity (PA) and nocturnal sleep influence each other, with daytime PA patterns potentially playing a key role in determining sleep quality. This study examined the association between daytime PA patterns, including their regularity and fragmentation, and sleep cycle stability, as a potential marker of sleep quality in healthy young male adults. Sleep cycle stability was defined as the stability of the rapid eye movement-non-rapid eye movement (REM-NREM) sleep cycle. Sixteen participants wore accelerometers for 6–8 days to measure daytime PA patterns and underwent polysomnography to assess sleep. The regularity (PAr) and fragmentation (PAf) of daytime PA patterns were calculated from accelerometer data, while sleep cycle stability (SCs) and other sleep parameters were derived from hypnograms. Pearson correlation analysis revealed a positive correlation between PAr and SCs, and a negative correlation between PAf and SCs. Furthermore, SCs showed a positive correlation with mean sleep efficiency, and negative correlations with the mean values of sleep latency and REM sleep latency (REM latency), as well as the standard deviations of these parameters. These findings suggest that more regular and less fragmented daytime PA patterns are associated with more stable sleep cycles, which in turn is linked to shorter sleep and REM latency, higher sleep efficiency, and greater day-to-day stability in these parameters. Interventions targeting daytime PA patterns may provide a potential new avenue for improving sleep quality.
