Associations Of Wrist-measured Physical Activity With Self-reported Moderate-to-vigorous Physical Activity And Sedentary Behavior: NHANES 2011-2014

Abstract

It remains unknown what individuals are attempting to convey, in terms of wrist-measured objectively monitored physical activity (PA), when self-reporting their leisure-time moderate-to-vigorous PA (MVPA) and sedentary behavior (LTSB). PURPOSE: To examine wrist-measured objectively monitored PA across groupings of self-reported leisure-time MVPA and LTSB in US adults (≥ 18 yrs). METHODS: A secondary analysis of data from the 2011-2012 and 2013-2014 National Health and Nutrition Examination Survey (NHANES) was performed. Weekly frequencies and average daily durations for self-reported moderate and vigorous activities were used to derive weekly MVPA. Self-reported MVPA was then dichotomized into two groups based upon compliance to PA guidelines (< 150 vs. ≥ 150 min/week). Screen time was quantified from questions about daily TV and computer usage. An LTSB variable was then created by dichotomizing total daily screen time at its median (< 3 vs. ≥ 3 hr/day). Participants also completed a 7-day objective wrist-worn accelerometer PA assessment. Mean daily PA was quantified in monitor independent movement summary (MIMS) units. Participants (n = 8,949) who provided complete questionnaire responses and ≥ 4 valid days accelerometer data (≥ 10 hr/day) were retained for analyses. Mean wrist-measured objectively monitored PA was modelled as a function of self-reported MVPA and LTSB using complex samples regression. RESULTS: Participants reporting compliance to PA guidelines accumulated significantly more wrist-measured PA (13,722 ± 96.3 MIMS/day) than those not compliant to current guidelines (13,004 ± 83.2 MIMS/day; p < 0.001). Participants reporting <3 hr/day LTSB were significantly more active (14,063 ± 96.1 MIMS/day) than those accumulating ≥3 hr/day (12,664 ± 61.7 MIMS/day, p < 0.001). Cross-classification of self-reported MVPA status and LTSB indicated those achieving PA guidelines and accumulating <3 hr/day LTSB were the most physically active grouping (14,279 ± 122.7 MIMS/day), while those not achieving PA guidelines and accumulating ≥3 hr/day of LTSB were the least active grouping (12,161 ± 74.9 MIMS/day; p < 0.001) CONCLUSION: Consistent with results from previous waist-measured PA studies, wrist-measured PA significantly varied across self-reported leisure-time MVPA and LTSB levels.