2.1. Self-Service Technology and Self-Service Fitness Centers
Self-service Technology (SST) refers to those technological interfaces that enable users to obtain services directly in most cases without the need for staff participation [
18]. This concept was first proposed by Dabholkar to explain the self-service process involving technological interfaces [
19]. Compared to traditional face-to-face service interactions, SST transfers some of the service processing responsibilities to customers, reducing reliance on staff. Today, SST is widely used in various industries. For example, in the hotel and tourism industry, customers can independently complete check-in, check-out, ticketing, and ordering services through SST[
20].
SST offers numerous benefits to service providers, including cost reduction, enhanced service quality, efficiency, and productivity [
21,
22,
23], and bolstered corporate image that attracts new customer segments [
24]. Concurrently, it provides greater convenience for consumers, in terms of location, accessibility, time, and cost savings [
25,
26]. By standardizing services and reducing the impact of human factors on the service experience, SST is perceived to better fulfill customer needs, thereby improving customer satisfaction and loyalty [
27]. However, customers' attitudes towards this unstaffed service are not always positive. Existing studies have investigated customer acceptance of self-service from perspectives of technology readiness [
28], technological characteristics [
29], and consumer traits [
30]. Other researchers have explored the impact of self-service on customer satisfaction and loyalty in different service sectors, such as postal services and online retail [
31,
32], and how various factors, such as the presence of staff and locational convenience, affect customers' attitudes towards SST usage [
33]. These prior studies demonstrate that customers' attitudes towards self-service are not static, but are influenced by the specific service environment and service delivery circumstances. Currently, research results related to self-service in the fitness service environment and customers' views on different service interaction methods are not clear.
Against the backdrop of digital transformation, numerous global large-scale chain fitness centers have begun to actively adopt the self-service model, such as Anytime Fitness in the United States, JOYFIT and Fastgym24 in Japan, The Gym Group and PureGym in the United Kingdom, and Supermarket and Lefit in China. In China, fitness centers that only provide fitness space, based on Internet of Things and Internet technologies, can implement remote automated control of lighting, access control, and air conditioning ventilation systems, enabling the fitness centers to operate 24 hours a day on a self-service basis. These fitness centers are known as self-service fitness centers, unstaffed fitness centers, or 24-hour fitness centers [
34]. This model leverages high-quality group classes as a competitive strategy, with class retailing and membership fees as the core profit model. Through applications and online platforms, self-service fitness centers offer efficient course scheduling and virtual guidance, while big data analysis provides customers with personalized fitness suggestions. In the physical fitness environment, self-service kiosks, smart access controls, vending kiosks, and other self-service facilities simplify the process of customer registration, booking, and payment, enabling unstaffed operations. However, this does not imply that customers lack support during fitness activities. On the contrary, dedicated staff monitor the fitness center remotely to ensure customer safety and smooth service delivery. Customers can also contact customer service via telephone or onsite communication devices. Staff can arrive on site within a short period to handle relevant matters. This mode of service ensures customer support while providing flexible self-service.
2.2. The Relationship between Service Quality, Customer Satisfaction, and Behavior Intentions
Understanding consumers' perceptions of service quality is crucial for sports and fitness centers aiming to enhance their management efficiency and maintain competitiveness, representing a focal point in contemporary quality management within the service sector [
35,
36]. However, due to the intangible nature of services, service quality proves challenging to measure accurately. Consequently, early research harbored various interpretations of the definition of service quality and its measurement models. Initially, researchers defined it as the gap between customer expectations and their perceptions of actual service performance [
37,
38]. Building on this, Parasuraman et al. designed the SERVQUAL, a five-dimension service quality measurement tool applicable across all services [
38]. However, the tool's validity and applicability encountered criticism from some researchers. For instance, Cronin and Taylor's study suggested that the SERVPERF scale, which concentrates on perception, demonstrated superior validity in assessing service quality compared to SERVQUAL [
39]. Therefore, Cronin et al. proposed conceptualizing service quality as a consumer's perception structure based on performance [
40], while the specific dimensions should vary depending on the service context [
41]. For instance, within the fitness service field, researchers have developed new assessment tools due to SERVQUAL's inability to provide dimensions specific to the context of fitness centers, such as the QUESC scale developed by Kim et al. for Korean sports center service quality [
42], the SSQRS leisure sports service quality scale proposed by Ko et al. [
43], and the SQAS service quality assessment scale established by Lam et al. based on American fitness centers [
44].
Customer satisfaction refers to consumers' evaluations and emotional reactions to a product or service [
45], typically categorized into transaction-specific satisfaction and cumulative satisfaction. Transaction-specific satisfaction involves the assessment of a particular product or service, while cumulative satisfaction pertains to the overall evaluation of a product or service [
46]. Among these, cumulative satisfaction has been proven to be more stable and effective in predicting customer loyalty [
47,
48] and has been widely adopted in research in the field of fitness services [
3,
49,
50]. Therefore, in this study, customer satisfaction is defined as customers' overall assessment of the fitness center and its service experience.
The relationship between service quality and customer satisfaction has been empirically supported in early studies, with service quality widely regarded as a significant predictor of customer satisfaction [
51]. For instance, the study by Rust and Oliver suggested that customer satisfaction is directly dependent on service quality [
52]. In the relationship between service quality and customer loyalty, Taylor et al. observed that service quality should directly influence customer satisfaction, which in turn elevates customer loyalty [
53]. In the fitness service domain, Foroughi et al. underscored the positive correlation between service quality and customer satisfaction in the context of Malaysian fitness centers [
54]. A recent review study further confirms that customers' positive perceptions of the service quality in fitness centers lead to increased customer satisfaction [
55]. Therefore, self-service fitness centers that provide superior service quality are more likely to boost customer satisfaction. Based on the above theories and research, we propose the following hypothesis:
H1.
There is a positive correlation between service quality and customer satisfaction.
Loyalty is often defined in the literature as "a steadfast commitment to re-purchase a favorite product or service in the future, despite situational influences and marketing efforts that might cause switching behavior" [
45]. There are mainly two perspectives on measuring loyalty: the behavioral perspective and the attitudinal perspective. The behavioral perspective emphasizes customers' actual behaviors, such as the frequency and persistence of purchasing behavior [
56]. The attitudinal perspective, on the other hand, focuses on customers' behavioral intentions, such as the willingness to repatronage services or recommend them to others [
5]. Oliver suggested that actual behavior is often guided by behavioral intentions [
48], a viewpoint also supported by attitude-behavior theories and goal theories [
57]. Therefore, by comparison, the attitudinal perspective is often considered more helpful for a more comprehensive understanding of loyalty formation. In this study, we follow this perspective. In the prior studies on attitude structure, Zeithaml et al. pointed out that repatronage intentions and WOM intentions are key indicators to assess customer loyalty [
5]. These two indicators are related to customer retention and are widely used in the sports and fitness service domain [
58,
59]. However, due to the lack of significant association between repatronage intentions and WOM intentions, researchers suggest treating them as two separate structures for deeper analysis [
17,
60]. This study follows this suggestion.
Service quality has been proven to have a positive impact on customer loyalty, especially in relation to repatronage intentions and WOM intentions. Bitner et al. found that service quality has a direct impact on customers' WOM and repurchase intentions [
61]. Empirical research conducted by De Ruyter et al. under five different service environments reached similar conclusions [
62]. This relationship has been verified in recent empirical studies, such as enhancing customer recommendation and revisit intentions by improving service quality in self-service [
27], and the direct connection between e-service quality and customers' green purchase intentions [
63]. In the field of fitness services, a study by Zopiatis et al. under the environment of hotel fitness centers found that the dimension of fitness facilities in service quality has a direct impact on customers' future intentions [
64]. Therefore, a high level of perceived service quality by customers could potentially contribute to more positive behavioral intentions. Based on the aforementioned research, we propose the following hypotheses:
H2a.
There is a positive correlation between service quality and customers' WOM intentions;
H2b.
There is a positive correlation between service quality and customers' repatronage intentions.
2.3. The Relationship between Service Convenience, Service Quality, Customer Satisfaction, and Behavioral Intentions
Research has pointed out that time scarcity is a significant issue faced by consumers worldwide [
65]. The aspiration to minimize the expenditure of time and effort has increasingly become a key demand of consumers towards service providers. Consequently, service convenience has been widely incorporated into service and management research in recent years. Service convenience refers to consumers' perception of the time and effort required to purchase or use a service [
66]. This definition, proposed by Berry et al., has been widely accepted. Service convenience is divided into five dimensions: decision convenience, access convenience, transaction convenience, benefit convenience, and post-benefit convenience, which encompass the entire process of customers selecting services, accessing services, transacting services, benefiting from services, and maintaining relationships with service providers. Studies have indicated that the evaluation of service convenience must be combined with the specific service environment and consumer experience [
67]. For instance, in the context of e-retail services, the convenience of decision-making, transactions, benefits, and post-benefit would have a more significant impact on consumer behavior intentions [
68]. In mobile banking services, users' service evaluations would be significantly influenced by access, transactions, benefits, and post-benefit convenience [
69]. Therefore, the five-dimensional structure of service convenience may not be applicable in all services. A similar situation may occur in self-service fitness center. Factors such as operating hours, service methods, and automated payment methods may affect customers' perceptions of convenience. Hence, further analysis of the service convenience in self-service fitness centers is needed.
Previous research has emphasized the direct relationship between service convenience and service quality [
66]. In some service industries, such as mobile phone services and retail banking services, the dimensions of convenience have had a positive impact on the perception of service quality [
70]. Similarly, Reynaldo et al. found in their study on long-distance logistics services that the perceived service convenience enhanced the perceived service quality [
71]. These studies suggest that convenient services might improve perceived service quality by reducing customers' investment in time and effort [
72]. However, the influence of service convenience on service quality in the fitness service field has rarely been touched upon in current research. As self-service fitness centers gain a competitive edge by offering highly convenient services, we infer that customers might consider service convenience an essential factor when assessing service quality. Based on the above discussion, we propose the following hypothesis:
H3.
There is a positive correlation between service convenience and service quality.
Existing research has observed a direct relationship between service convenience and customer satisfaction, encompassing both physical services and online services [
73,
74]. For instance, Bi et al., in their study on online tourism shopping services for the elderly, and Benoit et al., in their study on in-store services, both found that the dimensions of service convenience had a significant impact on customer satisfaction [
75,
76]. In the field of fitness services, research by García-Fernández et al. showed that besides decision convenience, the dimensions of access, transaction, benefit, and post-benefit convenience had a direct and significant impact on customer satisfaction in low-cost fitness centers, subsequently influencing customer loyalty [
3]. Given the potential of convenient service delivery in a SST environment to improve customer satisfaction, we propose the following hypothesis:
H4.
There is a positive correlation between service convenience and customer satisfaction.
Service providers are advised to always prioritize offering convenient services, as it directly influences customer loyalty [
66]. Some prior research has examined the impact of service convenience on the behavioral intentions aspect of customer loyalty. For instance, studies by Ozturk et al. in hotel booking services, and Eryiğit et al. in the field of e-services, have both demonstrated that service convenience directly influences consumers' repurchase and referral intentions [
77,
78]. Similarly, in the fitness service field, a study by Baena-Arroyo et al. on fitness centers in Spain showed a positive and significant direct relationship between service convenience and customers' future intentions [
12]. These studies suggest that customers who perceive higher service convenience are more likely to generate behavior intentions favorable to service providers [
68]. Thus, we propose the following hypotheses:
H5a.
There is a positive correlation between service convenience and customers' WOM intentions;
H5b.
There is a positive correlation between service convenience and customers' repatronage intentions.
2.5. The Mediating Role of Service Quality and Customer Satisfaction between Service Convenience and Behavioral Intentions
Based on the discussed impact relationships among service convenience, service quality, customer satisfaction, and behavioral intentions, i.e., service convenience can positively impact service quality and customer satisfaction [
71,
74], and the latter can enhance customers' WOM intentions or repatronage intentions [
63,
79]. We further speculate that there may exist a chain-like mediating impact relationship, i.e., a high level of service convenience might act as a driving factor, enhancing customers' evaluations of service quality, subsequently improving customer satisfaction, and ultimately influencing customers' WOM intentions and repatronage intentions. This impact relationship reveals the possible path for service convenience to influence customers' behavioral intentions through service quality and emphasizes the key role of service quality and customer satisfaction in this process. Therefore, based on the above discussion, we propose the following hypotheses:
H7a.
Service quality plays a mediating role between service convenience and WOM intentions;
H7b.
Customer satisfaction plays a mediating role between service convenience and WOM intentions;
H7c.
Service quality and customer satisfaction play a chain-mediated role between service convenience and WOM intentions;
H8a.
Service quality plays a mediating role between service convenience and repatronage intentions;
H8b.
Customer satisfaction plays a mediating role between service convenience and repatronage intentions;
H8c.
Service quality and customer satisfaction play a chain-mediated role between service convenience and repatronage intentions.
2.6. The Moderating Role of With Staff Versus Without Staff Presence
Generally, the fitness service industry involves direct interactions between staffs and customers. As soon as customers walk through the door, interaction occurs. Therefore, face-to-face service interaction has always been a key factor for fitness centers to establish strong customer relationships [
84]. Based on this service inertia, some self-service fitness centers still arrange a few employees on site to assist customers in using SST. Compared to Without Staff service methods, With Staff means that customers can directly see and interact with staffs while using self-service [
33]. This is similar to on-site assistance services in other industries, such as banks and supermarkets.
Previous studies have explored the impact of different service methods on customer evaluations. Empirical research in the hotel and airline service industries indicates that employee image, courtesy, and proactive response are closely associated with customer perceptions of service quality and satisfaction [
85,
86]. Service research in the restaurant industry has shown that direct interaction between staffs and customers positively influences repatronage intentions [
87]. However, over-interaction could lead to service redundancy and customer complaints, thereby reducing customer satisfaction and loyalty [
88]. On the other hand, SST is enhancing service convenience by reducing and replacing staff-customer interactions [
89]. This unstaffed methods of service has been found beneficial for improving customers' evaluations of service quality, satisfaction, and loyalty [
90]. However, customers' views on service interaction methods may vary depending on the type of service. For example, research in the retail service field found that under Without Staff conditions, customer satisfaction is usually lower than under With Staff conditions [
91]. In self-service retail stores, customers usually wish to see staff during the transaction process [
89]. In the field of fitness services, staffs' professional skills, social skills, and communication abilities have been observed to have a significant impact on customer satisfaction and behavior intentions [
54,
92]. Therefore, it is believed that the service methods, either With Staff or Without Staff, could moderate the relationships among the constructs of service quality, service convenience, customer satisfaction, and loyalty, and we propose the following hypothesis:
H9.
The service methods of with staff and without staff have significant differences in the impact on the relationships among service quality, service convenience, customer satisfaction, WOM intentions, and repatronage intentions.