The main finding of this study was that the perception of the environment altered after the walking intervention in the themes of "distance", "availability of bike lane", "availability of infrastructure", "maintenance of infrastructure", "network" and "safety traffic" without changing the environment. However there were some interactions between baseline PA and the achievement of "3000 steps more per day" in the themes of "availability of bike lane", "maintenance of infrastructure", "network" and "safety traffic" which indicates that baseline PA as well as the increase in steps (PA) has an influence on some changes in perception of the environment. It can be assumed that simply wearing the pedometer and getting aware of the personal PA goals, can lead to a higher sensitivity for the own environment. In line with the statement of Ries and colleagues , increasing exposure to the neighborhood environment may result in changes in environmental perceptions related to PA. Importantly, all changes in environmental perceptions were in a favorable way, considering the environment as more inviting to be physically active.
However, our results do not allow us to conclude about the direction of cause and effect, why the environmental perception changed. Either increased PA levels resulted in a higher exposure to the environment or the change in perception "caused" an increase in PA. Adding to the discussion whether objective or perceived environmental measures are necessary to understand the relationship concerning PA [2, 5], our results suggest to combine both measures in future studies as the perception seems to be influenced by the exposure to the environment. This aspect should be taken into account and further research on this issue is warranted.
The strength in the present study is that the intervention was carried out in a small isolated and controlled community so that caused changes could be rather explained through the PA intervention itself and not through potential changes in the environment. However, also external influences on the environmental perception such as the season can be an issue in allowance of starting the intervention in winter and ending in spring, or even the attendance in the optional PA events. Furthermore PA was monitored during the whole intervention and not only around post-measurements which is beneficial. Nevertheless there are some limitations to the study. Firstly there was no control group and the sample size was small. Secondly a generalisation of the results is limited, because the study was just conducted in one small rural village and results could differ for urban or suburban communities. Even so, we see important findings in the results of our study which have not been investigated sufficiently in the present literature.