Variability in physical activity patterns as measured by the SenseWear Armband: how many days are needed?

To examine sources of variance in objectively measured physical activity and to determine the number of monitoring days needed to quantify physical activity patterns reliably, 394 Flemish adults (41.1 ± 9.9 years) were monitored during 7 days, using the SenseWear Armband. Differences between weekdays, Saturday and Sunday were examined with repeated measures ANOVA’s. Variance components were estimated for subject, weekday and residual error using...