Discussion
Three important findings emerged from the present study. First, the results suggest significant overall increases in physical activity and self-control in both conditions. Also, both groups maintained their levels of physical activity and self-control until 4 weeks after the end of the intervention. Second, participants of the treatment group showed greater increases in MET’s as compared to participants in the comparison group. Third, participants with higher initial levels of conscientiousness were better able to increase their daily steps during the intervention and participants who increased more in self-control showed greater increases in MET’s. These effects were more pronounced in the treatment group as compared to the comparison group. However, it should be noted that these three-way interactions involve relatively small numbers and should be interpreted with caution.We found significant group differences in terms of changes in MET’s. However, changes in self-control, daily steps, and MVPA did not differ between the two conditions. The increases of the comparison group suggest that daily reminders and activity feedback on the Fitbit device alone are helpful micro interventions to support people on their journey of becoming more self-controlled and more active. In fact, a recent meta-analysis (The results differed somewhat depending on the activity outcome which was used (i.e. MET’s, daily steps or MVPA). That is, the treatment group showed greater increases in MET’s, but not in daily steps or MVPA, when compared to the comparison group. It is important to note that participants could choose what type of exercise they wanted to implement in their daily life and could set their own activity goal. The IPAQ was used to measure MET’s, which is a valid measure, has acceptable measurement properties, and shows good test-retest stability (The results also suggest that those of the treatment group with higher initial levels in conscientiousness or greater increases in self-control were better able to increase their physical activity as compared to those of the comparison group. Previous research also found that participants with higher conscientiousness were better able to increase their levels of physical activity when taking part in a physical activity intervention (