DIFFERENTIATING BETWEEN LOW LEVEL ACTIVITIES IN SEDENTARY OCCUPATIONS UTILIZING FITBITS

Objective: Fitbits are popular devices used to track personal activity throughout the day. The potential usage of these devices in tracking sedentary activities in research studies rely on the validity and accuracy of the devices. The objectives of this study are to investigate if changes in daily activity is associated with changes in duration of standing time using a sit-to-stand workstation. Also to establish if an accelerometer may be used to detect differences between sitting and standing sedentary positions. Methods: Sixteen participants wore Fitbit accelerometers throughout the workday and were emailed surveys on a weekly basis to report their sitting and standing percentages. Spearman correlation was used to compare mean daily step counts and mean standing percentages. A subsample of seven participants wore Fitbit and completed log sheets detailing precise periods of sitting and standing while at work. The number of steps registered during sitting and standing periods was compared for each individual using a paired t-test. Results: No statistically significant correlation was found between a participant’s mean standing percentage and mean daily step count (p-value = 0.563). Paired t-test analysis of participants found no statistically significant difference between the total number of steps registered while sitting and the total number of steps registered while standing (p-value = 0.034). Conclusions: No observable association between daily activity and duration of standing time was found. The number of steps measured using a Fitbit accelerometer may not be a useful method to assess sit-to-stand workstation usage. Limitations with the study included possible selection bias, incomplete self-reporting surveys, low sample sizes and short study durations. Future studies accounting for these limitations may prove to yield more statistically significant results regarding the use of Fitbits in assessing sedentary activity