| الوصف: |
This study aimed to determine the impact of cab noise when driving Heavy Goods Vehicles (HGV) on cut-point estimated moderate-to-vigorous physical activity (MVPA) from wrist-worn accelerometers. First, we investigated the impact of cab noise on accelerometer output during HGV driving and then on cut-point estimated MVPA in HGV drivers. CAB NOISE : A GENEActiv accelerometer was located beneath the seat in six HGVs for 8-days. Acceleration recorded during driving lay predominantly (~94%) within the sedentary range (<40m g ). MVPA : HGV drivers (N=386, 47.9±9.3 years) wore a wrist-worn GENEActiv and a thigh-worn activPAL simultaneously for 8-days covering workdays and non-workdays. MVPA recorded by the activPAL excludes seated transport, thus provided the criterion. Wrist-accelerometer MVPA was classified using two cut-points approximating 3 METs (MVPA100m g ) and 4.3 METs (indicative of brisk walking, MVPABRISK_WALK). Acceleration classified as MVPA100m g or MVPABRISK_WALK during activPAL-determined seated transport was considered erroneous. Across all-days, activPAL MVPA was 15 (IQR: 9, 26) min/day. Compared to activPAL, MVPA100m g was 100 min/day higher (95% limits of agreement (LoA) +/-53 min), but MVPA BRISK_WALK similar (mean bias = -2 min/day, 95% LoA +/- 15). On workdays, 23 (IQR: 11,52) min of MVPA100m g and 2 (1,7) min of MVPA BRISK_WALK , were erroneous. However, on non-workdays, only 4 (3,14) and 0.4 (0,1) min, respectively, were erroneous. In conclusion, MVPA may be erroneously captured using cut-point analyses of accelerometer data in HGV drivers. However, this was substantially reduced by using an MVPA cut-point indicative of brisk walking, which also approximated activPAL estimated MVPA. |