Using SAS® Arrays to Calculate Bouts of Moderate to Vigorous Physical Activity from Minute-by-Minute Fitbit Data

Abstract

The increasing popularity and affordability of wearable fitness tracking devices, together with their ability to provide granular physical activity data down to the minute-level, has enabled researchers to conduct advanced studies on the effects of physical activity on health and disease. This technology also provides statistical programmers the challenge of processing these data and translating them into analyzable measures. One such measure is the number of time-specific bouts of moderate to vigorous physical activity (MVPA), (akin to ‘exercise’) which is needed to determine if the participant meets current physical activity guidelines (e.g.,150 min.of MVPA/week performed in bouts of at least 10 min.). In this paper, we illustrate how we used SAS® arrays to calculate the number of 10-min.bouts of MVPA per day and provide a working code that can be run on a sample file