Global obesity rates are worryingly high and are climbing in many countries. For example, 1 in 3 adults and 3 in 25 children in New Zealand are obese [1]. Long-term obesity is linked to numerous chronic and life-threatening illnesses such as stroke, diabetes, and heart disease [2]. Aside from the personal toll of these complications, treating obesity-related illnesses is very expensive. For instance, the associated public healthcare costs in New Zealand are around NZ$2 billion annually [3]. Thus, trying to reduce obesity is good for the general public’s quality of life and would free up money within the health sector for other needs. To address this social need, a branch of computer graphics research called ‘serious gaming’ has been looking into developing ‘exergames’, which use gamification to engage users with exercise activities. But why make a video game to address obesity?

Currently, video games are the largest media industry in the world, producing more money than both the music and movie industries combined [4]. If an exergame could engage users with exercise while gaming, it could translate to the player reaching recommended physical activity goals [5]. Since video gaming is both widely popular and usually a sedentary activity, gamers are a worthy target demographic for research to counter obesity and promote a more active lifestyle. An exergame may also appeal to non-gamers too.

Smartphone devices appear to be a compelling choice of platform for developing exergames [6]. This is for two main reasons. First, smartphones are very accessible, with a user base in the billions [7]. Second, smartphones are lightweight, small, and wireless. This makes them well suited for use alongside many forms of exercise which require mobility, such as running and field sports. Several ‘location-based’ mobile exergames have proven to be highly popular too, such as 2016’s Pokémon GO [8], which still has millions of active users. Alongside their popularity, several studies have shown that such mobile exergames have both positive psychological effects [6] and increase their users’ daily step counts [9]. With this proven potential in mind, the development of such mobile exergames has become an active subfield of ‘serious game’ research and development. For example, the terms ‘mobile’ and ‘exergame’ together return over 5,500 results in Google Scholar, with the majority of those articles being released in the last 4 years alone.

Despite this vast number of exergames being developed by academics and students, not all of these ventures have successfully engaged their players [10]. A 2023 systematic literature review of the effectiveness of exergames, a majority of which were developed for smartphones, found that most exergames amounted to being just a ‘novelty’ and failed to maintain user engagement and increased exercise levels in the long term [10]. But the same review also found that exergames which consciously applied psychological research when designing their gameplay were more engaging and proved to be more effective at altering long-term behavioural patterns [11].

Music is already an important part of many people’s exercise routines, including dance classes such as Zumba [12], background music at gyms, and jogging with earphones in. Indeed, the psychological benefits of listening to music while exercising have been well studied. For example, it is known that listening to music reduces the perceived effort of low to moderate exercises (such as walking) by as much as ten per cent [13]. This ‘ergogenic’ psychological effect has been observed in weightlifting too [14]. It has also been shown that music generally enhances the endurance of those exercising, with a slightly more pronounced effect when the music is the choice of the exerciser [15].

It has previously been shown that this ergogenic effect spawned from music can be applied fruitfully in exergames [16]. However, few papers have experimented with using music-based rhythm gameplay in a mobile exergame. One example is Komninos et al.’s [17] ClearBeatWalker, which encouraged their users to maintain an optimal walking pace by using music. If the user was not meeting the required walking pace, the music’s sound quality was reduced [17]. Similarly, Otsubo et al. [18] produced BeatSync, an exergame that synchronised the music’s beats per minute (BPM) with the user’s steps per minute (SPM). However, their gameplay involved adjusting the volume level rather than sound quality [18]. A major drawback of both papers is that they did not allow users to select their own music for the exercise, instead listening to a predefined song selection chosen by the researchers. This seems like a significant oversight, as people’s music tastes vary dramatically.

My approach with this project was to fill this research gap by experimenting if the ergogenic effect of listening to music can be enhanced when the choice of music is that of the user. The natural technology to enable this functionality in a mobile exergaming app would be a music streaming service, as such services already enable on-demand audio playback of millions of songs. Thus, my research question was

“Does the freedom of song selection enabled by music streaming make a mobile rhythm-exergame more engaging?”