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There are three physical activity objective monitors and a single combined wear log covering both monitors.

ActiGraph

The ActiGraph GT3X physical activity monitor measures acceleration in 3 axis, body position, and ambulation (steps). Participants wore the ActiGraph GT3X monitor two times during the study with six months between administrations. The monitor was placed on an elastic belt and participants were instructed to wear the belt on their waist with the monitor positioned over their right hip, directly under the right armpit. Participants were asked to wear the ActiGraph GT3X monitors all day, including naptimes, for seven days, and to remove the monitors when showering, bathing, and swimming and for bed at night. Participants were asked to wear the monitor for seven days, but some participants chose to wear the monitor for additional days beyond the specified week.

ActiGraph GT3X monitor data are provided in three formats: by 60-second, 10-second and 1 second epoch.

A small portion of the raw one second ActiGraph data is not included in the 10 second and 60 second summaries. The first 7 days of data (the protocol period) are always kept. Days outside the first week may be kept if the physical activity log indicates continued wear.

Click here for data dictionaries and formats for the ActiGraph files. Datasets can be obtained by submitting a request.

Summary
  • Monitor recorded data
  • Worn twice for 7 days:
    • Groups 1&3 in Month 0 and Month 6
    • Groups 2&4 in Month 6 and Month 11
  • ~935 Participants
    • ~805 completed both administrations
    • ~90 completed only the 1st
    • ~40 completed only the 2nd
Available Data

ACTIGRAPH 10 & 60–SECOND EPOCH DATA

  • Date and time
  • Vector Magnitude (total acceleration per epoch, calculated as the sum over 10 seconds of the 1 second vector magnitude)
  • Inclinometer (orientation of monitor)
  • Accumulated steps per epoch
  • Vertical, horizontal and perpendicular axis acceleration data
  • Status: continuous walking/running, intermittent lying/sitting
  • Energy Expenditure value (EE) and METS calculated by the Crouter two-regression model on one axis (EE is not in 60-second data)
  • Wear log data – information provided by the participant about when they wore the device and reason for removing it. This data was entered by the participant and may differ from the monitor.

ACTIGRAPH 1-SECOND EPOCH DATA

  • Date and time (HH:MM:SS with hours 0-23)
  • Vector Magnitude (total acceleration per epoch, calculated as: vector magnitude = square root of (axis12 + axis22 + axis32))
  • Inclinometer (orientation of device)
  • Accumulated steps per epoch
  • Vertical, horizontal and perpendicular axis acceleration data