How do relative time in moderate-to-vigorous physical activity corresponds to the 2020 guidelines on physical activity and sedentary behaviour?

AbstractBackgroundMore and more researchers have started to analyse physical activity data using compositional data analysis (CoDA), which has led to that the effect of relative time in different behaviours can be explored. However, there are challenges related to interpretation of the results based on CoDA. This is partly related to that CoDA provides estimates based on relative time that is difficult to interpret in relation to the 2020 guidelines of physical activity and sedentary behaviour. Since many data cohorts do not have data on sleep, the proportion of time in physical activity may vary depending on how large part of the day in awaken behaviours is recorded. Therefore, there is a need of explore cut-points for relative time to distinguish between individuals that do and do not reach 150–300min of moderate-intensity physical activity (MVPA).MethodTo estimate the cut-off points of relative time in MVPA, the publicly available data of NHANES 2003–2006 was used and cut-off points were explored in different subsets of the total population. Values for sensitivity, specificity and cut-off values were explored in; i) total sample, ii) tertiles of wear time, iii) individuals with ± 5 min from physical activity recommendation, iiii) individuals with 5 min from PA recommendation in the middle tertile of wear time.ResultsOverall, the analyses show high values for sensitivity (88–100%) and specificity (66–99%) for different cut-off values associated with 150–300min of MVPA. Spending 2.4–4.7% of the time awake in MVPA was found to correspond to the 2020 guidelines of physical activity and sedentary behaviour.ConclusionThis finding is helpful when analysing physical activity data using CODA in datasets where sleep is not available and when interpreting diagrams depicting relative time in different behaviours.