Use of a Sit-Stand Desk Reduces Wake Time During the Subsequent Night’s Sleep

Acute bouts of leisure-time physical activity commonly improve sleep on the subsequent night. However, the impact of sedentary behavior on sleep is unclear. Further, whether breaking up sedentary time during the workday improves the following night’s sleep is unknown. PURPOSE: To examine whether breaking up prolonged sedentary time by standing during the workday leads to better sleep the following night in comparison to a sedentary workday. METHODS: 25 inactive adults with untreated pre- or stage 1 hypertension (16 males, 42±12 yr, body mass index: 31.9±5.0 kg/m2) participated in a randomized crossover trial consisting of two simulated 8-h workdays: one with continuous sitting (SIT) and one with alternating periods of sitting and standing every 30 min (SIT-STAND). Sleep was assessed on the night following each simulated workday. Participants completed a diary to indicate sleep onset latency (SOL), number of awakenings, wakefulness after sleep onset (WASO), and depth and quality of sleep. Participants also wore an accelerometer on the non-dominant wrist (Philips Actiwatch Spectrum) to objectively assess sleep (bedtime, out-of-bed time, total sleep time, SOL, WASO). Paired t-tests and effect size calculations were used to evaluate differences in sleep following the two conditions. RESULTS: Diary-based WASO was significantly lower following SIT-STAND compared to SIT (13.9±30.1 min vs. 23.2±38.6 min; P=.03, d=0.47). Self-reported SOL, awakenings, sleep depth, and sleep quality were not significantly between conditions, though SIT-STAND led to small-sized reduction in SOL and awakenings (d=0.33 and d=0.29, respectively). There was a small-sized reduction in actigraphic WASO following SIT-STAND compared to SIT (30.2±12.7 min vs. 37.7±25.0 min; d=0.39), though this difference was not statistically significant (P=.09). Actigraphic estimates of bedtime, out-of-bed time, total sleep time, and SOL did not differ between conditions (P>.61, d<0.11). CONCLUSION: Alternating sitting and standing during the workday leads to small improvements in sleep on the night following the simulated workday, particularly in reduced wake time. Whether this effect on sleep remains or is enhanced with long-term reduction in workplace sedentary behavior deserves further exploration.