Interactivity has remained a central concept in digital media, continually evolving alongside technological advancements and interface innovations. As computing transitions from the personal desktop era to the mobile age and into the current era of ubiquitous computing, definitions of interactiv- ity have expanded—from discrete user commands to more embodied, con- tinuous, and context-sensitive exchanges. This evolution has had profound implications for persuasive technology, where interactivity plays a dual role: enhancing user engagement and enabling real-time, adaptive feedback that can more effectively influence users’attitudes and behaviors. These develop- ments set the stage for new modalities that incorporate internal physiological signals, opening opportunities for immersive systems that adapt dynamically to users’ bodily states.

This study investigates the integration of real-time physiological biofeed- back into Virtual Reality (VR) as a novel form of persuasive interaction. While traditional Human-Computer Interaction (HCI) has evolved from explicit in- put methods to more embodied and context-aware interfaces, the potential of internal signals—such as heart rate—as active input in immersive media remains underexplored, particularly in the domain of persuasive technology aimed at influencing users’attitudes and behaviors. Drawing from theories and model in persuasive technology and other HCI frameworks, this research introduces BioVR, a VR cycling system where users’heart rates dynamically control environmental elements like speed and lighting. Through a mixed- methods user study comparing BioVR with a control condition using only an Apple Watch, the findings show that BioVR significantly improves time spent in target heart rate zones and self-reported engagement. Qualitative insights reveal that responsive environmental feedback fosters intrinsic motivation, distracts from fatigue, and enhances time perception.

This work makes three key contributions.

• Theoretically, it proposes and validates a new interaction paradigm in VR—biosignal-driven feedback loops—advancing the ongoing shift from Human-Computer Interaction (HCI) to Human-Computer Integration (HInt).
• Conceptually, it extends the persuasive technology framework by demonstrating how internal physiological states can serve as dynamic input for immersive environments, offering an embodied and continuous mecha- nism for behavior change.
• Practically, it offers design implications for adaptive fitness technologies that support users in maintaining effective exertion levels through responsive, affective feedback, rather than relying on traditional performance metrics or external motivators.