## 2 Theoretical Model and Hypotheses
### Based on the Hypotheses of the Research Framework Model
Specifically, users confirm their expectations based on their initial interaction with the product, which in turn affects their decision to continue using it [38]. Studies have shown that individuals with higher levels of trialability tend to view the system as both more practical and easier to use [39]. Based on these considerations, the following hypotheses are proposed:  
**H3a:**: _The trialability of fitness apps positively influences the perceived ease of use of Asian seniors._
**H3b:**: _The trialability of fitness apps positively influences the perceived usefulness of Asian seniors._  
Gamification (GA) is a method of assessing Asian seniors' evaluation of the settings and processes of gamification in fitness apps. Although gamification in fitness apps can potentially modify the user's state, supporting engagement and learning, the application of feedback and point modification is likely to enable the feeling of purpose [24]. Additionally, the social gamification components in these apps foster social comparisons and create connections among users, enabling them to support one another while working toward shared goals [40]. [PERSON] et al. [41] outlined key principles of gamification that can be applied to explain goal setting and its significance, provide guidance for older users through a predetermined journey, offer immediate feedback, and amplify users' achievements. Moreover, gamification can provide real-time feedback, enhance positive performance, and break down complex tasks into simpler, manageable steps. Fitness apps incorporatinggamification allow users to set personal goals, choose various progression paths, and adjust difficulty levels based on individual capabilities. Based on these considerations, the following hypotheses are proposed:  
**H4a:**: _The gamification of fitness apps positively influences the perceived ease of use of Asian seniors._
**H4b:**: _The gamification of fitness apps positively influences the perceived usefulness of Asian seniors._  
Observability (OB) is the extent to which others can observe the results brought by using a fitness app by Asian senior users. This concept deals with the observability of the innovation itself in a social context. Most fitness apps not only provide sports rankings, but also provide users with display platforms such as electronic medal walls as honorary awards to enable participants to visualize their results [42]. These results are not only displayed on social software but also linked to other social media. In this context, the higher the level of older users on the platform, the more chances they have to gain attention and appreciation from other users. Furthermore, these high levels of older users also report a stronger sense of personal fulfilment [43]. The greater the exposure an innovation receives, the greater the likelihood that potential users will adopt it [44]. The ease with which the benefits of an innovation can be demonstrated to others is a significant factor in its adoption. In this context, OB, which refers to the ability of individuals to learn the use of innovation with less effort and to clearly explain its use and benefits to others [45], plays an important role. Based on this, it is hypothesized that outcome demonstrability will positively influence perceived usefulness (PU) and perceived ease of use (PEU). **H5a:**: _The observability of fitness apps positively influences the perceived ease of use of Asian seniors._
**H5b:**: _The observability of fitness apps positively influences the perceived usefulness of Asian seniors._  
Perceived ease of use (PEU) refers to the degree to which older adults find fitness apps easy to navigate and understand. A reduction in the complexity of the innovation leads to a decrease in the cognitive and effort resources required to learn and use it, thereby lowering the overall cost of adoption. Perceived usefulness (PU), on the other hand, is the extent to which older adults believe that using fitness apps enhances their physical and mental well-being.