Physical Activity, Sedentary Behavior and Sleep in Adolescents - Weekday and Weekend Patterns

Abstract

In adolescents sleep behavior differs markedly between weekdays and weekend days. The implications of this disparity for the associations among sleep, physical activity and sedentary behavior are unclear. PURPOSE: To determine if there are significant differences in physical activity and sedentary behavior between students who experience adequate vs. inadequate sleep, analyzing weekday and weekend data separately. METHODS: The School Sleep Habits Survey was used to measure total sleep time on weekends and weekdays. Sleeping ≥8 hours per night was considered adequate sleep (AS), while sleeping <8 hours was considered inadequate sleep (IS). Accelerometry was used to measure sedentary behavior (SB) and total physical activity (PA) on weekdays and weekends. SB was determined by the total minutes/day below 100 counts/minute, while PA was determined by the total minutes/day at, or above 100 counts/minute. The sample consisted of 261 9th grade adolescents. Over half were male (59%). A majority were African American (52%). Average weekday PA was compared between the AS group and the IS group using weekday sleep data. The same was done using weekday SB. Average weekend PA was compared between the AS group and the IS group using weekend sleep data. The same was done using weekend SB. T-tests were used to determine significant differences between groups. RESULTS: There were more students in the AS group (n = 156) than the IS group (n = 96) on weekends, and more students in the IS group (n = 169) than the AS group (n = 92) on weekdays. There were no statistically significant differences between PA and SB levels by sleep group, on weekends and weekdays. CONCLUSION: Students who experienced adequate levels of sleep did not differ in their levels of PA from those who experienced inadequate sleep. This was the case on weekends and weekdays. Similarly, students who experienced adequate levels of sleep did not differ in their levels of SB from those who experienced inadequate sleep. This was also the case for weekends and weekdays. Supported by NHLBI Grant 2R01HL091002-07. This publication was made possible in part by Grant Number T32- GM081740 from NIH-NIGMS. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIGMS or NIH.