Table 4. Derived Variables and Cut Point Definitions Used in Studies Published Since 2007 (or Forthcoming) on Accelerometer Data for Children and/or Adolescents, National Health and Nutrition Examination Surveys, 2003–2004 and 2005–2006.
| Accelerometer-derived variable | Cut point definition | Reference |
|---|---|---|
| Mean activity counts/min | Sum of daily activity counts/number of min worn | (2,26,35) |
| Time in sedentary behaviors | <100 Activity counts/min | (3,30,47) |
| Sedentary behavior bout | ≥30 Min with ≥80% of min <100 activity counts/min (no more than 5 consecutive min ≥100 activity counts/min | (47) |
| Break min | Within each sedentary behavior bout (defined above), those mins ≥100 activity counts/min | (47) |
| Time in incidental movement (any movement) | <2,000 Activity counts/min | (48) |
| Time in low intensity (any movement) | 2,000–2,999 Activity counts/min | (48) |
| Time in low intensity | Between 100 activity counts/min and age-specific cut point definitions (55) | (47) |
| Time in moderate-intensity activity (any min) | Age-specific cut point definitions (55) | (2,30,38) |
| Time in moderate-intensity activity (any min) | 3000–5,199 Activity counts/min | (48) |
| Time in moderate- intensity activity (modified 10-min bouts) | Age-specific cut point definitions (55) | (2) |
| Time in vigorous-intensity activity (any min) | Age-specific cut point definitions (55) | (2,30) |
| Time in vigorous-intensity activity (any min) | ≥5200 Activity counts/min | (48) |
| Time in vigorous-intensity activity (modified 10-min bouts) | Age-specific cut point definitions (55) | (2) |
| Time in MVPA (any min) | Age-specific cut point definitions (55) | (2,25,26,30,31,34,35,47,54) |
| Time in sporadic MVPA (any min <5 min) | Age-specific cut point definitions (55) | (34) |
| Time in sporadic MVPA (any min <10 min) | Age-specific cut point definitions (55) | (34) |
| Time in MVPA (any min) | ≥1,500 Activity counts/min | (24) |
| Time in MVPA (any min) | ≥3,000 Activity counts/min | (8,39,42) |
| Time in MVPA (1- to 4-min bouts) | ≥3000 Activity counts/min | (39,42,45) |
| Time in MVPA (modified 5- to 9-min bouts) | ≥3000 Activity counts/min | (39,42,45) |
| Time in MVPA (modified 10-min bouts) | ≥3,000 Activity counts/min | (39,42) |
| Time in MVPA (≥5-min bouts) | Age-specific cut point definitions (55) | (34) |
| Time in MVPA (≥10-min bouts) | Age-specific cut point definitions (55) | (34) |
| Time in moderate-intensity activity (modified 10-min bouts) | Age-specific cut point definitions (55) | (2) |
| Time in total PA | ≥2,000 activity counts/min | (8) |
| Adherence to PA recommendations (children, any min; adolescents, any min and modified 10-min bout) | 30 min of moderate- or greater-intensity activity on 5 of 7 d | (2) |
| Uncensored (raw) steps/d | Reporting steps as detected | (4) |
| Censored steps/d | Disqualify steps taken <500 activity counts/min | (4) |
| Sedentary | <10,000 Steps/d (boys aged 6–11); <7,000 steps/d (girls aged 6–11) | (4) |
| Low active | 10,000–12,499 Steps/d (boys aged 6–11); 7,000–9,499 steps/d (girls aged 6–11) | (4) |
| Somewhat active | 12,500–14,999 Steps/d (boys aged 6–11); 9,500–11,999 steps/d (girls aged 6–11) | (4) |
| Active | 15,000–17,499 Steps/d (boys aged 6–11); 12,000–14,499 steps/d (girls aged 6–11) | (4) |
| Highly active | ≥17,500 Steps/d (boys aged 6–11); ≥14,500 steps/d (girls aged 6–11) | (4) |
Abbreviations: PA, physical activity; MVPA, moderate- to vigorous-intensity PA.