Background: Accurate measurement of physical activity patterns can be used to identify sedentary behaviour and may facilitate interventions aimed at reducing inactivity. Objective: To evaluate the activPAL physical activity monitor as a measure of posture and motion in everyday activities using observational analysis as the criterion standard. Methods: Wearing three activPAL monitors, 10 healthy participants performed a range of randomly assigned everyday tasks incorporating walking, standing and sitting. Each trial was captured on a digital camera and the recordings were synchronised with the activPAL. The time spent in different postures was visually classified and this was compared with the activPAL output. Results: Intraclass correlation coefficients (ICC 2,1) for interdevice reliability ranged from 0.79 to 0.99. Using the Bland and Altman method, the mean percentage difference between the activPAL monitor and observation for total time spent sitting was 0.19% (limits of agreement 20.68% to 1.06%) and for total time spent upright was 20.27% (limits of agreement 21.38% to 0.84%). The mean difference for total time spent standing was 1.4% (limits of agreement 26.2% to 9.1%) and for total time spent walking was 22.0% (limits of agreement 216.1% to 12.1%). A second-by-second analysis between observer and monitor found an overall agreement of 95.9%. Conclusion:The activPAL activity monitor is a valid and reliable measure of posture and motion during everyday physical activities.

A large number of older adults in low-income settings are currently experiencing sleep problems, which emphasizes the global dimension of this emerging public health issue. This study corroborates the multifaceted nature of sleep problems, which are strongly linked to poorer general well-being and quality of life, and psychiatric comorbidities.

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Compliance with physical activity (PA) recommendations was assessed using objective PA monitoring of ambulatory activity, in two healthy groups of individuals with active and sedentary occupations. The study showed generally low compliance with the guidelines (53% with 10,000 steps a day; 10% with 30 min of moderate activity a day; and 1% with 30 min of moderate activity a day in bouts of at least 10 min (ACSM)). Adherence to guidelines decreased as more rigorous conditions were applied to the PA data. Use of an objective monitor revealed that health enhancing bouts of activity were performed in periods of approximately 1-min duration, which may be due to unavoidable environmental interruptions. These bouts of activity are much shorter than those advocated in the ACSM guidelines, raising questions regarding how actual behaviour, based on objective monitoring, can be reconciled with guidelines based on self-reported PA.