TY - JOUR AU - Herrmann, Lynn Katherine AU - Kim, Jinsook PY - 2017 TI - The fitness of apps: a theory-based examination of mobile fitness app usage over 5 months JF - mHealth; Vol 3 (January 2017): mHealth Y2 - 2017 KW - N2 - Background: There are thousands of fitness-related smartphone applications (“apps”) available for free and purchase, but there is uncertainty if these apps help individuals achieve and maintain personal fitness. Technology usage attrition is also a concern among research studies on health technologies. Methods: Usage of three fitness apps was examined over 5 months to assess adherence and effectiveness. Initially, 64 participants downloaded three free apps available on Android and iOS and 47 remained in the study until posttest. With a one group pre-posttest design and checkpoints at months 1, 3, and 5, exercise and exercise with fitness apps were examined in the framework of the Theory of Planned Behavior (TPB) using a validated survey. Apps were selected based on their function from the Functional Triad. Perceived fitness was also measured. T -tests, sign tests, Fisher’s exact tests, and linear and logistic regression were used to compare pre to posttests and users to non-users of the apps. Results: Forty-seven participants completed both pre and posttests. Individual item scores indicated no significant change pre to posttest except for decreases observed in usefulness of using apps for exercise (attitude) (−0.78, P Conclusions: App usage and effectiveness appears to have a connection to usefulness (attitude) and to perceived difficulties of exercising using apps (perceived behavioral control). Exercise and exercise using apps are not influenced by peer influence (subjective norm). Intention to exercise using these particular apps decreased (behavioral intention). Those who utilized the apps were more likely to have a positive attitude about the apps. Usefulness and perceived difficulties in particular should be considered with future app development. App usefulness and ease of use may be facilitated by using health behavior theories to guide development. UR - https://mhealth.amegroups.org/article/view/13393