At the Speed of the Heart: Evaluating Physiologically-Adaptive Visualizations for Supporting Engagement in Biking Exergaming in Virtual Reality

TL;DR

This paper presents a VR cycling exergame that uses real-time heart rate data and gamified visualizations, like NPCs, to help users stay within their target exertion levels, enhancing engagement and workout regulation.

Contribution

It introduces a physiologically-adaptive visualization system for VR exergaming that dynamically adjusts feedback based on heart rate zones, a novel approach in this domain.

Findings

Gamified NPC visualizations improved engagement and feedback effectiveness.

The adaptive system helped users maintain their target heart rate zones.

Subjective enjoyment and motivation were unaffected by the adaptation.

Abstract

Many exergames face challenges in keeping users within safe and effective intensity levels during exercise. Meanwhile, although wearable devices continuously collect physiological data, this information is seldom leveraged for real-time adaptation or to encourage user reflection. We designed and evaluated a VR cycling simulator that dynamically adapts based on users' heart rate zones. First, we conducted a user study (N=50) comparing eight visualization designs to enhance engagement and exertion control, finding that gamified elements like non-player characters (NPCs) were promising for feedback delivery. Based on these findings, we implemented a physiology-adaptive exergame that adjusts visual feedback to keep users within their target heart rate zones. A lab study (N=18) showed that our system has potential to help users maintain their target heart rate zones. Subjective ratings of exertion, enjoyment, and motivation remained largely unchanged between conditions. Our findings suggest that real-time physiological adaptation through NPC visualizations can improve workout regulation in exergaming.