Accelerometer and diary
An accelerometer (Hookie, tri-axial, “AM20 Activity Meter”, Hookie Technologies Ltd, Espoo, Finland) was provided with detailed written and oral instructions. The accelerometer was worn on the right hip for 7 consecutive days following the face-to-face interview and returned by prepaid mail or if necessary picked up. Participants were instructed to wear the accelerometer daily from waking up to going to sleep, removing it for water activities only.