A randomized controlled trial utilizing an interactive accelerometer linked to a smartphone application for enhancing physical activity and health among military employees.

Introduction: The primary objectives of the present individualized randomized controlled trial were to increase physical activity (PA) and improve physical fitness.

Materials and methods: 260 military employees around Finland participated. Two-thirds, (158), were randomized in the intervention and one-third, (101), in the control group. The intervention group used Exsed Movesense accelerometers linked to smartphones measuring PA and sleep for six months. They received feedback via a smartphone application, were encouraged to exercise during worktime for 2 hours/week, and participated in telephone counseling. The control group continued PA routines without the accelerometer or feedback. Measurements were taken at the baseline, 6-mo and 12-mo after the intervention. They included two-week RM 42-accelerometer measurements of PA, cardiometabolic biomarkers, body composition, physical fitness tests, and a questionnaire about stress and work ability for the intervention group at every point and for the control group at baseline and 12-mo. At the 6-mo, only PA was measured in the control group. Primary outcomes were changes in PA from baseline to 6-mo and 12-mo as well as changes in maximal oxygen uptake and fitness index from baseline to 12-mo. Secondary outcomes were changes in other parameters from baseline to 12-mo. The effect of the intervention on primary and secondary outcomes was analyzed using unadjusted generalised linear mixed model, accounting for a group-by-time interaction effect in all models.

Results: There was no statistically significant group-by-time interaction regarding the measured parameters. However, amount the intervention group daily standing time (mean increase 18 min/day, 95% confidence interval [CI] 6-29 min/day) and maximal oxygen uptake (mean increase 2.15 ml/kg/min 95% CI 0.56-3.74 ml/kg/min) tended to increase during twelve months.

Discussion: The intervention did not effectively change the primary outcomes, but showed encouraging trends and revealed the potential and challenges of the intervention developed to increase PA in a military workplace.