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Table 1 Accelerometer-determined physical activity and sedentary behavior variable definitions

From: Adult self-reported and objectively monitored physical activity and sedentary behavior: NHANES 2005–2006

Variable Definitions
  Physical activity monitor (PAM) compliance indicator*
Accelerometer wear time 1,440 minutes minus non-wear time [12].
  Volume indicators*
  Steps
Uncensored steps/day Total raw steps accumulated over 1,440 minutes [19].
Censored steps/day Total steps accumulated over 1,440 minutes after censoring steps accumulated at intensities < 500 activity counts/minute [19].
  Activity counts
Activity counts/day Total activity counts accumulated over 1,440 minutes [16].
  Rate indicators*
  Steps
Uncensored steps/minute Total raw steps accumulated over 1,440 minutes, divided by accelerometer wear time [16].
Censored steps/minute Total steps accumulated over 1,440 minutes after censoring steps taken at intensities < 500 activity counts/minute, divided by accelerometer wear time [16].
Peak 1-minute cadence Steps/minute recorded for the highest single minute in a day [17].
Peak 30-minute cadence Average steps/minute recorded for the 30 highest, but not necessarily consecutive, minutes in a day [17].
  Activity counts
Activity counts/minute Total activity counts accumulated over 1,440 minutes, divided by accelerometer wear time [12].
  Time indicators*
  Cadence
Non-movement Total minutes at 0 steps/minute during valid wear time [18].
Incidental movement Total minutes at 1–19 steps/minute [18].
Sporadic movement Total minutes at 20–39 steps/minute [18].
Purposeful steps Total minutes at 40–59 steps/minute [18].
Slow walking Total minutes at 60–79 steps/minute [18].
Medium walking Total minutes at 80–99 steps/minute [18].
Brisk walking Total minutes at 100–119 steps/minute [18].
Faster locomotion Total minutes ≥ 120 steps/minute [18].
Any movement Total minutes > 0 steps/minute [18].**
Non-incidental movement Total minutes > 19 steps/minute [18].**
  Activity intensity
Sedentary time Total minutes < 100 activity counts/minute [15].
Low intensity Total minutes at 100–499 activity counts/minute [16].
Light intensity Total minutes at 500–2,019 activity counts/minute [19].
Lifestyle intensity Total minutes at 760–2,019 activity counts/minute [13].
Moderate intensity Total minutes at 2,020-5,998 activity counts/minute [12].
Vigorous intensity Total minutes ≥ 5,999 activity counts/minute [12].
Moderate-to-vigorous intensity Total minutes ≥ 2,020 activity counts/minute [12].
Moderate-to-vigorous intensity in 10 minute bouts Total minutes ≥ 2,020 activity counts/minute accumulated in modified 10 minute bouts [12].†
  Breaks in sedentary time*
Transitions/day Number of occurrences where activity counts rose from < 100 activity counts in one minute to ≥ 100 activity counts in the subsequent minute [14].
  1. *Values averaged over valid days (≥ 10 hours/day of wear time).
  2. **Variables not previously defined but derived from previously published variable definitions [18].
  3. †10 or more consecutive minutes ≥ 2,020 activity counts/minute, with allowance for 1–2 minutes < 2,020 activity counts/minute.