Background The use of health and fitness apps has been on the rise to monitor personal fitness and health parameters. However, recent research discovered that many users discontinue using these apps after only a few months. Gamification has been suggested as a technique to increase users’ interactions with apps. Nevertheless, it is still not clear how gamification mechanisms encourage continued use and inspire user self-management. Objective The main objective of this study was to articulate how gamification mechanisms in studies of designing and using health and fitness apps can contribute to the realization of information technology (IT) identity and positive behavioral outcomes. The broader goal was to shed light on how gamification mechanisms will translate into positive use behaviors in the context of mobile health apps. Methods Data were collected from 364 users of health and fitness apps through an online survey to empirically examine the proposed model. Results Based on identity theories, this study suggests the fully mediating role of IT identity to describe how gamification elements can lead to continued intention to use health and fitness apps, and increase users’ tendency for information sharing through the apps. The findings indicate that perceived gamification can increase users’ IT identity. In turn, a higher IT identity would encourage users to continue using the apps and share more personal health information with others through the apps. Conclusions The results of this study can have practical implications for app designers to use gamification elements to increase users’ dependency, relatedness, and emotional energy associated with health apps. Moreover, the findings can have theoretical contributions for researchers to help better articulate the process in which gamification can be translated into positive use behaviors.