Evidence suggests sleep and physical activity (PA) are associated with each other and dementia risk. Thus, identifying reliable methods to quantify sleep and PA concurrently in older adults is important. The MotionWatch 8© (MW8) wrist-worn actigraph provides reliable estimates of sleep quality via 14 days of measurement; however, the number of days needed to monitor PA by MW8 for reliable estimates is unknown. Thus, we investigated the number of days of MW8 wear required to assess PA in older adults. Ninety-five adults aged > 55 years wore MW8 for ≥ 14 days. Spearman-Brown analyses indicated the number of monitoring days needed for an ICC = 0.95 was 6–7 days for sedentary activity, 9–10 days for light activity, and 7–8 days for moderate-to-vigorous PA. These results indicate 14 days of MW8 monitoring provides reliable estimates for both sleep and PA. Thus, MW8 is ideal for future investigations requiring concurrent measures of both sleep quality and PA.
Ryan S. Falck, Glenn J. Landry, Keith Brazendale and Teresa Liu-Ambrose
Keith Brazendale, Michael William Beets, Robert Glenn Weaver, Jennifer Huberty, Aaron E. Beighle and Russell R. Pate
Afterschool programs (ASPs) can provide opportunities for children to accumulate moderate-to-vigorous physical activity (MVPA). The optimal amount of time ASPs should allocate for physical activity (PA) on a daily basis to ensure children achieve policystated PA recommendations remains unknown.
Children (n = 1248, 5 to 12 years) attending 20 ASPs wore accelerometers up to 4 nonconsecutive week days for the duration of the ASPs during spring 2013 (February–April). Daily schedules were obtained from each ASP.
Across 20 ASPs, 3 programs allocated ≤ 30min, 5 approximately 45 min, 4 60 min, 4 75 min, and 4 ≥ 105 min for PA opportunities daily (min·d-1). Children accumulated the highest levels of MVPA in ASPs that allocated ≥ 60 min·d-1 for PA opportunities (24.8–25.1 min·d-1 for boys and 17.1–19.4 min·d-1 for girls) versus ASPs allocating ≤ 45 min·d-1 for PA opportunities (19.7 min·d-1 and 15.6 min·d-1 for boys and girls, respectively). There were no differences in the amount of MVPA accumulated by children among ASPs that allocated 60 min·d-1 (24.8 min·d-1 for boys and 17.1 min·d-1 for girls), 75 min·d-1 (25.1 min·d-1 for boys and 19.4 min·d-1 for girls) or ≥ 105 min·d-1 (23.8 min·d-1 for boys and 17.8 min·d-1 for girls). Across ASPs, 26% of children (31% for boys and 14% for girls) met the recommended 30 minutes of MVPA.
Allocating more than 1 hour of PA opportunities is not associated with an increase in MVPA during ASPs. Allocating 60 min·d-1, in conjunction with enhancing PA opportunities, can potentially serve to maximize children’s accumulation of MVPA during ASPs.
Jessica L. Chandler, Keith Brazendale, Clemens Drenowatz, Justin B. Moore, Xuemei Sui, Robert G. Weaver and Michael W. Beets
Background: The primary purpose of this study was to determine which physical activity (PA) opportunity elicits the most moderate to vigorous PA (MVPA) in after-school programs. This study used a 3-group cross-over design in which participants were exposed to 3 variations of activity structures: free play, organized, or a mixture. Methods: PA was measured using ActiGraph GT3X+ accelerometers. All data were transformed into percentage of time spent sedentary or in MVPA. Repeated-measures mixed-effects models were used to examine differences in MVPA and sedentary among the 3 activity sessions. Participants included 197 unique children, aged 5–12 years, and were 53% male and 55% white. Results: Statistically significant differences were observed in the percentage of time boys spent in MVPA during free play and mixed compared with organized only sessions (35.8% and 34.8% vs 29.4%). No significant difference was observed in the percentage of time girls spent in MVPA during free play compared with organized or mixed (27.2% and 26.1% vs 26.1%). Both boys and girls experienced ∼10% less time sedentary during free play compared with the others. Conclusion: Offering free play during PA opportunities can help children attain as much if not more MVPA compared with only offering organized, adult-led games.