Delayed sleep timing is associated with low levels of free-living physical activity in normal sleeping adults.

ABSTRACT: We and others have reported that experimentally induced short sleep does not affect resting metabolic rate and leads to increased laboratory-measured 24-h energy expenditure. Here, we aimed to determine if sleep timing and/or quality are related to physical activity (PA) levels.Measures of PA via waist actigraphy, sleep diary, and sleep quality questionnaires were collected over a 7-18-day period in 22 adults (mean age?±?standard deviation (SD): 35.8?±?4.6 years, and mean body mass index?±?SD: 23.8?±?1.1?kg/m(2)) who were on their habitual sleep-wake and activity schedules.During the recording period, mean (±SD) bedtime and wake times were 00:17?±?1:07?h (range: 22:02-02:07?h) and 08:20?±?1:14?h (range: 06:30-10:11?h), respectively. After controlling for sleep duration, later bedtime, wake time, and midpoint of sleep were associated with less time spent in moderate-to-vigorous PA (p?=?0.013, p?=?0.005, and p?=?0.007, respectively), and increased time in sedentary PA (p?=?0.016, p?=?0.013, and p?=?0.013, respectively).Current results suggest that even relatively small alterations in sleep timing may influence PA. However, causality cannot be inferred from this cross-sectional study. Clinical intervention studies should be conducted to assess the relationship between sleep timing and energy balance.

SUBMITTER: Shechter A 

PROVIDER: S-EPMC4260995 | biostudies-literature | 2014 Dec

REPOSITORIES: biostudies-literature