JMIR Publications

ABSTRACT

Background:

Regular moderate to vigorous physical activity (PA) is essential for maintaining health and preventing the onset of chronic diseases. Both global rates of smartphone ownership and the market for PA and fitness apps have grown rapidly in recent years. The use of PA and fitness apps may assist the general population in reaching evidence-based PA recommendations. However, it remains unclear whether there are evidence-informed PA apps and whether behavior change techniques (BCTs) previously identified as effective for PA promotion are used in these apps.

Objective:

This study aimed to identify English and German evidence-informed PA apps and BCT employment in those apps.

Methods:

We identified apps in a systematic search using 25 predefined search terms in the Google Play Store. Two reviewers independently screened the descriptions of apps and screenshots applying predefined inclusion and exclusion criteria. Apps were included if (1) their description contained information about PA promotion; (2) they were in English or German; (3) PA recommendations of the World Health Organization or the American College of Sports Medicine were mentioned; and (4) any kind of objective PA measurement was included. Two researchers downloaded and tested apps matching the inclusion criteria for 2 weeks and coded their content using the Behavioral Change Technique Taxonomy v1 (BCTTv1).

Results:

The initial screening in the Google Play Store yielded 6018 apps, 4108 of which were not focused on PA and were not in German or English. The descriptions of 1216 apps were further screened for eligibility. Duplicate apps and light versions (n=694) and those with no objective measurement of PA, requiring additional equipment, or not outlining any PA guideline in their description (n=1184) were excluded. Of the remaining 32 apps, 4 were no longer available at the time of the download. Hence, 28 apps were downloaded and tested; of these apps, 14 did not contain any PA guideline as an app feature, despite mentioning it in the description, 5 had technical problems, and 3 did not provide objective PA measurement. Thus, 6 were included in the final analyses. Of 93 individual BCTs of the BCTTv1, on average, 9 (SD 5) were identified in these apps. Of 16 hierarchical clusters, on average, 5 (SD 3) were addressed. Only BCTs of the 2 hierarchical clusters “goals and planning” and “feedback and monitoring” were identified in all apps.

Conclusions:

Despite the availability of several thousand PA and fitness apps for Android platforms, very few addressed evidence-based PA guidelines and provided objective PA measurement. Furthermore, available descriptions did not accurately reflect the app content and only a few evidence-informed PA apps incorporated several BCTs. Future apps should address evidence-based PA guidelines and a greater scope of BCTs to further increase their potential impact for PA promotion.