To identify cross-sectional and seasonal patterns of sleep and physical activity (PA) in community-dwelling, older Icelandic adults using accelerometers.
Seven-day free-living protocol as part of a larger population-based longitudinal observational-cohort study.
Greater Reykjavik area of Iceland.
244 (110 female), older Icelandic adults (mean age 79.7±4.9 years). A subpopulation (n = 72) repeated the 7-day measurement during seasonal periods with greater (13.4±1.4 h) and lesser (7.7±1.8 h) daylight.
None.
Cross-sectional analyses using multiple linear regression models revealed that day length was a significant independent predictor of sleep duration, mid-sleep, and rise time (all p