Exercises have a wide variety of health benefits, but a large proportion of the population does not perform sufficient physical activity. A frequently cited reason is a lack of intrinsic motivation. Exergames have been proposed as a means to address this problem by combining exercises with an enjoyable game play. A particular useful form of exercises is HIIT (high intensity interval training), which involves alternating periods of intense exercise with periods of light exercise. However, few exergames attempt to implement high intensity protocols and their effectiveness remains uncertain. In this paper we present a novel VR exergame that utilises game-play mechanics synchronised with music rhythm, to automatically induce HIIT without the need for a physical instructor. The exergame involves the use of a rowing machine to synchronise oar movement with collectible rings in the game. The level of synchronisation directly determines the players score, and realtime feedback is given using a heads-up display. The distance between rings is changed to induce periods of varying intensity exercise. We tested our design using a two-way factor analysis (music on/off, gameplay on/off). A sample of 6 university students each completed all four conditions. Our results show that gameplay and music were both effective at inducing HIIT, while music had a stronger effect on both performance and perceptual variables. Music and gameplay both decreased perceived exertion over the no music + no game control. Music increased enjoyment over no music, and power output and rowing rate were both more consistent in the music condition.
