What technological features are used in smartphone apps that promote physical activity? A review and content analysis

Pers Ubiquit Comput (2017) 21:633–643 DOI 10.1007/s00779-017-1023-3 ORIGINAL ARTICLE What technological features are used in smartphone apps that promote physical activity? A review and content analysis J.S. Mollee 1 & A. Middelweerd 2 & R.L. Kurvers 1 & M.C.A. Klein 1 Received: 12 July 2016 / Accepted: 8 February 2017 / Published online: 5 July 2017 # The Author(s) 2017. This article is an open access publication Abstract Despite the well-known health benefits of physical activity, a large proportion of the population does not meet the guidelines. Hence, effective and widely accessible interventions to increase levels of physical activity are needed. Over the recent years, the number of health and fitness apps has grown rapidly, and they might form part of the solution to the widespread physical inactivity. However, it remains unclear to which extent they make use of the possibilities of mobile technology and form real e-coaching systems. This study aims to investigate the current landscape of smartphone apps that promote physical activity for healthy adults. Therefore, we present a framework to rate the extent to which such apps incorporate technological features. And, we show that the physical activity promotion apps included in the review implemented an average of approximately eight techniques and functions. The features that were implemented most often were user input, textual/numerical overviews of the user’s behavior and progress, sharing achievements or workouts in social networks, and general advice on physical activity. The features that were present least often were adaptation, integration with external sources, and encouragement through gamification, some form of punishment or the possibility to contact an expert. Overall, the results indicate that apps can be improved substantially in terms of their utilization of the possibilities that current mobile technology offers. * M.C.A. Klein 1 Department of Computer Science, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands 2 Department of Epidemiology and Biostatistics and the EMGO Institute for Health and Care Research, VU University Medical Center, De Boelelaan 1089a, 1081 HV Amsterdam, The Netherlands Keywords Systematic review . Smartphone apps . Mobile technology . Mobile interventions . Physical activity promotion . Healthy lifestyle 1 Introduction Despite the well-known health benefits of physical activity, 23% of the adult population worldwide does not meet the recommended guidelines [1]. Systematic reviews concluded that levels of physical activity in Europe vary across countries, ranging from 15.6% in Israel to 84.8% in Slovakia who met the guidelines [2]. In the Netherlands, approximately one third of the adult population does not meet the Dutch guidelines for healthy physical activity [3]. Moreover, compared to other European countries, Dutch people lead a relatively sedentary lifestyle, with 25% spending at least 8.5 hour sitting on a usual day and over 60% at least 5.5 hour [4]. Insufficient physical activity is one of the leading risk factors for premature mortality and avoidable health-related issues as cardiovascular diseases, cancer, and diabetes [1, 5]. Thus, effective and widely accessible interventions to increase levels of physical activity are needed. Smartphones and smartphone applications (apps) could be useful as mobile coaching systems that aim to increase levels of physical activity, as they are well intertwined in modern society, always accessible to the user, and because they can lower the barrier for people to address their health problems [6]. Despite the fact that many adults do not meet the activity guidelines, apps that focus on health and fitness promotion are popular. To illustrate, the numbers of health and fitness apps are still growing and the iTunes App Store contained 71,895 health and fitness apps in 2016 [7], including both free and paid apps. Moreover, also traditional interventions have been influenced by ICT developments and make use of mobile 634 phones and the internet. Web-based and mobile (app)-based interventions (i.e., eHealth and mHealth interventions) provide opportunities for delivering personalized materials to promote physical activity on a population level [8, 9]. Several reviews and meta-analyses of eHealth interventions targeting physical activity found small effects on levels of physical activity in favor of the intervention groups [9–11]. mHealth interventions that were included in systematic reviews and meta-analyses mainly consisted of interventions delivered via sms or a personal device assistant (PDA) and showed promising results [8, 12–14]. However, to date, no systematic reviews on the effectiveness of app-based interventions to promote physical activity are available. Smartphones offer a wide range of technological possibilities, as part of or in addition to techniques used in eHealth and mHealth, such as telecommunication, sensoring/monitoring, and any-time any-place support. Even though no systematic reviews on the effectiveness of mobile interventions to promote physical activity have been published yet, there are several content analyses available focusing on the inclusion of behavior change theories and behavior change techniques. Those reviews showed that the apps were generally lacking foundation in behavior change theories and the use of behavior change techniques that are associated with effectiveness [15–19]. Behavior change techniques that were often included in apps were selfmonitoring, providing feedback on performance and goalsetting [15]. However, sensoring and monitoring can be done in various ways and it remains unclear to what extent current physical activity apps make use of the technological possibilities to help the user to be physically active and thus actually deliver the promises of mobile coaching systems. For example, features as self-monitoring can be based on different types of inputs, e.g., user input (i.e., diary) or sensor data obtained from the phone or from external sensors, such as a Fitbit or a GPS-watch. Although some technological features can be mapped to behavior change techniques (that again can be associated with effectiveness), it is currently unknown what features implicate higher effectiveness of physical activity apps. It is an interesting first step to investigate the prevalence of those features in the current supply of physical activity apps. Therefore, the aim of the present paper is to inventory the landscape of the state-of-theart smartphone apps that promote physical activity, in order to (1) gain insight in technological possibilities and (2) identify missed opportunities. More specifically, a framework of technological features is proposed, and a set of apps is selected systematically for the content analysis to discern how often those features are implemented. In addition, it is investigated whether the price of an app and the type of app store (...truncated)