TRACK & ACT: a pragmatic randomised controlled trial exploring the comparative effectiveness of pedometers and activity trackers for changing physical activity and sedentary behaviour in inactive individuals

Abstract

Background: Pedometers have been shown to be effective for increasing physical activity, however the potential additional effects of activity trackers, and their added capacity to simultaneously modify sedentary behaviour, has not been thoroughly explored. This study aimed to explore the comparative effectiveness of two activity trackers and a pedometer for improving daily step count and moderate-vigorous physical activity (MVPA), and reducing sedentary behaviour in inactive adults.

Methods: 48 inactive participants were allocated to one of three groups based on their workplace. Each group randomly received either a Fitbit ONE, Jawbone UP or Digi-Walker SW200 pedometer (PED) for 8-weeks and an orientation session to their respective device. Participants were informed about the study aims and were provided with their respective devices and where applicable, the associated Apps. Participants intentionally received no other active intervention components to simulate as closely as possible the experience of purchasing a device 'off the shelf'. Step count, MVPA and time in sedentary behaviour were measured using accelerometry (Actigraph GT3X+) at baseline and four-, eight- and 16-weeks. Analyses were conducted using linear mixed-effect regression models to compare changes from baseline. Post-hoc tests of model estimates compared each activity tracker group to the pedometer group. Model estimates are reported for baseline-16 week follow-up.

Results: At baseline, average (standard deviation) step count, MVPA and time spent sedentary was 6557 (2111) steps/day, 23 (13) minutes/day and 10.3 (1.0) hours/day in the PED group, 7156 (1496) steps/day, 26 (12) minutes/day and 9.3 (1.2) hours/day in the ONE group and 6853 (1281) steps/day, 29 (10) minutes/day and 10.1 (1.0) hours/day in the UP group. At 16-weeks, based on estimates from the linear mixed-effect regression model, the ONE and UP groups increased step count by 129 steps/day (95% CI - 1497, 1754) and 504 steps/day more (95% CI - 1120, 2130), respectively, than the PED group. For MVPA, the ONE and UP groups increased by 2.3 min/day (95% CI - 10.9, 15.4) and 2.7 min/day more (95% CI - 10.5, 15.8), respectively, than the PED group. For sedentary behaviour, the ONE group had 34 min/day more in time spent sedentary than the PED group (95% CI - 35, 104), while the UP group had 53 min/day more in time spent sedentary than the PED group (95% CI - 18, 123).

Conclusions: All three groups demonstrated an increase in steps and MVPA, and a decrease in time spent in sedentary behaviour, however there was substantial individual variation in these outcomes indicating considerable uncertainty about the relative effectiveness of activity trackers and pedometers in improving PA and sedentary behaviour. Randomised controlled trials with adequate sample sizes are indicated.

Trial registration: ACTRN12623000027617 (retrospectively registered 11/1/2023).

Keywords: Activity trackers; Adults; Health-related behavior; Intervention; Pedometer; Physical activity; Sedentary behavior.

Fig. 1

CONSORT flow diagram of participant recruitment, enrolment and progression through the study. Note: PED = Digi-Walker SW200, ONE = Fitbit ONE, UP = Jawbone UP

Fig. 2

Mean (and 95% confidence interval) for daily steps, MVPA and sedentary behaviour at 0, 4, 8 and 16 weeks in the three groups, changes (Δ) from baseline. Note: PED = Digi-Walker SW200, ONE = Fitbit ONE, UP = Jawbone UP, MVPA = moderate to vigorous physical activity

Fig. 3

Waterfall plots for individual changes between baseline and week 16 for the outcomes of daily steps, MVPA and sedentary behaviour in each group. Note: PED = Digi-Walker SW200, ONE = Fitbit ONE, UP = Jawbone UP, MVPA = moderate to vigorous physical activity

Fig. 4

Group-by-time interactions from the linear mixed-effect regression analysis for changes from baseline for daily steps, MVPA and sedentary behaviour. The slope of the line represents the estimated values (based on the linear regression) for the mean effect for that group over time, with shaded areas representing the 95% confidence interval for that line. Points represent the observed group mean at each time point and error bars represent the 95% confidence interval about that mean. Note: PED = Digi-Walker SW200, ONE = Fitbit ONE, UP = Jawbone UP, MVPA = moderate to vigorous physical activity