The relationship between cell phone use, physical activity, and sedentary behavior in adults aged 18–80

Highlights

• The cell phone is primarily used as a leisure device.

• The cell phone is primarily used when sitting.

• The cell phone is positively associated with sedentary behavior.

• The cell phone is positively associated with being an “active couch potato”.

• The cell phone is not associated with volume or intensity of physical activity.

Abstract

Purpose

To assess situational cell phone use (i.e., sitting, standing, or physically active) and the relationship between cell phone use, physical activity, and sedentary behavior in adults 18–80 years old.

Methods

An on-line survey was completed by adults (N = 423; n = 256 females, 40 ± 16 years old) which assessed situational and total cell phone use, physical activity, and sedentary behavior.

Results

Mean cell phone use was 239 ± 224 min/day and 81% of respondents reported typically sitting when using the device. Linear regression found cell use was positively associated with sedentary behavior and the physical activity by sedentary behavior interaction term (i.e., assessment of the “active couch potato” phenomenon), negatively associated with age, and not related to physical activity or sex. ANCOVA revealed that high cell users participated in significantly more sedentary time (521 ± 23 min/d sitting) than low users (442 ± 17 min/d sitting) with no differences between high and moderate users (471 ± 21 min/d sitting) or between low and moderate users.

Conclusion

Cell phone use was positively associated with sedentary behavior and the physical activity by sedentary behavior interaction term but not physical activity. Implications are discussed in the context of behavioral economics.

Introduction

Approximately 50% of all adults in the United States (117 million people) have one or more chronic health conditions, with 25% having two or more chronic health conditions (Control & Prevention, 2013). Many deaths can be attributed to these chronic diseases, including 33% of all fatalities which are due to cardiovascular disease (Control & Prevention, 2013). Health risk behaviors contributing to these diseases include lack of adequate physical activity (Garber et al., 2011) and excessive sedentary behavior (Katzmarzyk et al., 2009, Warren et al., 2010). Regular participation in physical activity is inversely associated with the risk of developing several negative health outcomes. The benefits of physical activity include, but are not limited to, reduced incidence of cardiovascular disease/coronary artery disease, hypertension, stroke, osteoporosis, type 2 diabetes mellitus, metabolic syndrome, obesity, cancer, and depression, and premature mortality (Garber et al., 2011, Health and Services, 2008, Vogel et al., 2009). Conversely, excessive sedentary behavior is associated with a greater likelihood of several potentially deleterious health effects, including the metabolic syndrome, cardiovascular disease, and type 2 diabetes (Ford, Kohl, Mokdad, & Ajani, 2005; I.-M.; Lee et al., 2012, Owen et al., 2010).

In fact, simply taking active breaks during periods of sedentary time (e.g., standing or walking after several minutes of sitting), independent of physical activity, is associated with lower cardio-metabolic risk (Healy, Dunstan et al., 2008a, Healy, Dunstan et al., 2008b). The independent effects of sedentary behavior upon cardio-metabolic risk is further illustrated in research indicating that individuals who participate in at least the minimum physical activity recommendations (75 min per week of vigorous activity or 150 min per week of moderate aerobic activity) yet still engage in large amounts of sedentary behavior outside of the physical activity time are at an elevated risk for developing a disease relative to those who are concurrently physically active and less sedentary (Biswas et al., 2015, Owen et al., 2010). These individuals who are regularly physically active and simultaneously, highly sedentary have been deemed “active couch potatoes” (Biswas et al., 2015, Owen et al., 2010). Because of these independent health risks associated with both a lack of physical activity and excessive amounts of sedentary behavior, it is important to better understand factors which may influence both physical activity and sedentary behavior in order to improve public knowledge of what may contribute to the choice of participating in physical activity and sedentary behavior.

Despite these known risks, a majority of adults participate in inadequate amounts of physical activity and excessive sedentary behaviors (Control and Prevention, 2013, Garber et al., 2011, Health and Services, 2008, Troiano et al., 2008). The most common contributor to leisure time sedentary behavior is traditional forms of screen-based activities including surfing the internet, playing video games, and watching television (Hamilton et al., 2008, Rosenberg et al., 2010, Thorp et al., 2011, Tudor-Locke et al., 2010). The modern, internet-connected, cellular telephone (i.e., smartphone) provides access to these traditionally sedentary, screen-based activities via the convenience of a lightweight, mobile, hand-held device. The use of the cell phone has become quite prevalent to where it is now a ubiquitous artifact of modern life. As of 2016, 95% of American adults owned a cell phone, 77% of which were internet-enabled smartphones (Pew-Research-Center, 2017). Previous research demonstrates that college students use these devices an average of 279–528 min per day (Barkley and Lepp, 2016b, Junco and Cotten, 2012, Lepp et al., 2014, Roberts et al., 2014), with the highest users engaging with the device almost constantly (Lepp et al., 2014). About 77% of teenagers 12–17 years old own a cell phone and 92% report using the phone to go online daily; including 24% which say they are online “almost constantly” through their mobile device (Lenhart et al., 2015). Therefore, cellular telephone use can be considered a common behavior in individuals across a wide range of ages. Because of the prevalence of the cell phone, the access it provides to traditionally sedentary activities (i.e., screen-based activities), and the amount of time individuals spend using this device, it is worth considering behavioral health implications potentially related to cell phone use. This paper considers the relationship between cell phone use, physical activity, and sedentary behavior.

According to the theory of behavioral economics, the decision to participate in one of two competing behaviors is based upon the relative reinforcing (i.e., motivating) value of each of the two behaviors and the “cost” required to gain access to each (Epstein, 1998, King et al., 2002, Owen et al., 2000). “Cost” can be monetary or take the form of the work required to gain access to a behavior. In this study, the competing behaviors of interest are physical activity and sedentary behavior which are typically inversely related to each other (Mansoubi, Pearson, Biddle, & Clemes, 2014). The choice to participate in physical activity or sedentary behavior involves a dynamic interaction of a number of factors which include the individual's personal-level viewpoints such as attitudes and beliefs, in addition to environmental influences (Dishman, 1994, King et al., 2002). Previous research has indicated that sedentary behavior is highly motivating and individuals may be more willing to pay a higher “cost” to gain access to sedentary behavior than physical activity (Epstein, 1998, King et al., 2002, Owen et al., 2000). For example, sedentary behavior can be rewarding as it can be viewed as low “cost” (i.e., easy to do), reinforcing (e.g. TV, movies, videos have a high entertainment value), provides choices (e.g., a numerous array of shows and videos are available to watch, etc.), and provide immediate gratification (e.g., fun, entertainment) (Epstein, 1998). Whereas physical activity can be perceived as too high of “cost” (e.g., difficult) with little immediate reinforcements (Epstein, 1998). Therefore, if an individual views activities performed during sedentary behavior as more reinforcing (e.g., high entertainment, intrinsically motivated) than physical activity (e.g., difficult, extrinsically motivated), then sedentary activity is likely to be the behavior chosen and individuals may be willing to pay a greater “cost” to sit (Chatzisarantis and Biddle, 1998, Epstein, 1998, Mullan et al., 1997). However, if physical activity were more reinforcing (e.g., feelings of autonomy and mastery) than sedentary behavior (e.g., feelings of lack of accomplishment, boredom), individuals would be more likely to participate in physical activity and may be willing to pay a greater “cost” to access this behavior (Chatzisarantis and Biddle, 1998, Epstein, 1998, Mullan et al., 1997).

While some individuals may find physical activity more motivating, sedentary behavior is typically chosen if access to each (i.e., “cost”) is equivalent (Epstein, 1998). For example, greater motivation during traditionally-sedentary activities such as watching television, playing video games, and reading news articles, may be due to these activities being perceived as offering autonomy (i.e. independence), freedom of choice, competence, and social relatedness (Chatzisarantis & Biddle, 1998) in addition to being fun and enjoyable (Gaston, De Jesus, Markland, & Prapavessis, 2016). Of relevance to the current study is that the modern cell phone provides constant access to these traditionally sedentary, screen-based activities. Furthermore, smartphones are most often used for leisure purposes (Barkley and Lepp, 2016b, Lepp et al., 2017, Lepp et al., 2015). Leisure is intrinsically motivating due to the feelings of enjoyment, relaxation, freedom of choice, and autonomy it often produces (Y. Lee et al., 1994, Shaw, 1985). Therefore, if an individual is highly entertained when interacting with the cell phone while sitting during leisure time, this is reinforcing sitting behavior. Bearing this in mind, according to behavioral economics, the proliferation and functionality of smartphones may promote sedentary behavior as these devices increase the ease (i.e., reduce the “cost”) with which individuals can access a behavior (i.e., screen use) which is likely reinforcing and typically associated with sitting. In other words, the smartphone may be a potential promotor of sedentary behavior.

The extant literature which has focused on the relationship between cell phone use, physical activity, and sedentary behavior has examined only college students thus far. In this population, the evidence suggests that like more traditional screens (e.g., television, internet connected computers, video game systems), cell phone use is primarily a leisure activity (Lepp et al., 2017). Indeed, 70% of the time college students spend on their cell phone has been described as leisure (Barkley & Lepp, 2016b). These prior studies also suggest college students' cell phone use is positively associated with sedentary behavior (Barkley and Lepp, 2016b, Barkley et al., 2016, Lepp et al., 2013). Additionally, although no relationship was found between cell phone use and the volume of daily physical activity, research demonstrates that using the phone during exercise reduces exercise intensity (Rebold et al., 2015, Rebold et al., 2016) and the speed of free-living walking (Barkley & Lepp, 2016a). Furthermore, high frequency cell phone users are more likely to use the device during exercise and free-living walking compared to their low use peers (Barkley & Lepp, 2016b). Finally, research has demonstrated a negative relationship between cell phone use and cardiorespiratory fitness after controlling for sex, percent body fat, and self-efficacy for exercise (Lepp et al., 2013).

While cell phones provide access to a variety of screen-based activities that are traditionally defined as sedentary and their use is predictive of greater sitting in college-aged adults, cell phone use does not have to be a sedentary behavior. Cell phones are portable and therefore their use can occur during light to moderate physical activity (e.g., walking). Furthermore, there are a variety of cell phone functions which may promote physical activity and/or discourage sitting. For example, there are a wide array of cell phone applications (apps) which may have some utility in promoting participation in physical activity behavior (Althoff et al., 2016, Barkley et al., 2017, Glynn et al., 2014, Hebden et al., 2012, Howe et al., 2016, Lane et al., 2011, Turner-McGrievy et al., 2013, Wong, 2017). In other words, it is possible that these fitness apps may increase the reinforcing value of physical activity. Indeed, a recent study with college-aged individuals demonstrated smartphone use was actually associated with meeting physical activity guidelines due to the use of apps which monitor and encourage physical activity (Towne et al., 2017). Furthermore, results of a separate study suggest that the use of smartphone fitness apps may promote physical activity, however the effect appears to be modest (Coughlin, Whitehead, Sheats, Mastromonico, & Smith, 2016). All of this suggests that cell phone use may be associated with the “active couch potato” phenomenon (Biswas et al., 2015, Owen et al., 2010). In other words, cell phone use may encourage sedentary behavior while simultaneously prompting users to meet physical activity guidelines perhaps through the use of health-related apps. Indeed, Lepp and Barkley (2016) assessed sedentary behavior, physical activity and daily cell phone use in a sample of college students. Participants were divided into even tertiles based upon cell phone use (i.e., low, moderate, and high users). The relationship between sedentary behavior and physical activity was then assessed for each tertile. A significant negative correlation between physical activity and sedentary behavior was found in the low cell use group, this relationship weakened in the moderate use group, and then disappeared entirely in the high use group. These findings suggest that as cell phone use increases there may be a greater number of “active couch potatoes” weakening the relationship between physical activity and sedentary behavior. It is therefore plausible that the manner in which individuals use their cell phones may influence their corresponding physical activity and sedentary behavior. If individuals are using the cell phone to provide easy (i.e., low “cost”) access to traditional screen-based activities (e.g., streaming videos, playing video games) this may promote sitting. Conversely, if they are utilizing the cell phone to access fitness apps which are designed to reinforce physical activity this may promote that behavior.

While there is evidence supporting the notion that cell phones may be both a sedentary device which interferes with exercise and a device which provides access to some functions which may support physical activity, these findings are limited to college students and there is no research we are aware of examining adults beyond the age of traditional college students (e.g., ˃ 25 years old). It was logical for researchers to initially focus on college-aged (i.e., 18–25 years old) individuals because this is the first adult generation which has grown up entirely in the digital age, thus the cell phone is used in nearly all areas of their life (Lenhart et al., 2015, Lepp et al., 2014, Rainie and Perrin, 2017). However, examining adults beyond the college age is warranted as their cell phone use, physical activity, and sedentary behavior may be different from that of college students. While many adults (95%) beyond college age use cell phones, that use may be for different purposes (e.g., more work related and less leisure related) and total daily use may be less than that of college students (Wicklin, 2010, Zickuhr, 2011). Furthermore, age is positively associated with sedentary behavior (Matthews et al., 2008) and inversely associated with and physical activity (Hallal et al., 2012). Because of these potential age-related differences, we believe it is important to determine if cell phone use is associated with sedentary behavior and physical activity in adults of a wider age range than what has been examined previously.

Therefore, the purpose of this research was to examine the relationships between cell phone use, physical activity, and sedentary behavior in a broader range (18–80 years old) of American adults. While there is an established inverse relationship between cell phone use and age (Barkley and Lepp, 2016a, Barkley et al., 2016), the ability of cell phones to potentially decrease the “cost” to access traditionally-sedentary, screen-based activities while also providing access to apps which may make physical activity more motivating is likely the same in adults across a wider age range than has previously been examined. Therefore, it is hypothesized that adults will have similar relationships between cell phone use and physical activity and sedentary behavior to that of the previously-studied populations limited to college students. Specifically we hypothesized the following for our sample of adults aged 18–80:

• Because leisure is intrinsically motivating and the cell phone provides access to an array of leisure activities (e.g., videos, games, etc.), consistent with previous research, cell phone use will be primarily for leisure purposes.

• Because the cell phone makes it easier to access traditionally-sedentary, highly-motivating, screen-based activities, the majority of cell phone use will occur while sitting.

• Because we hypothesize that the majority of cell phone use will occur while an individual is sitting we further hypothesize that cell phone use will be positively related to sedentary behavior independent of sex and age.

• While there are certain cell phone functions (e.g., fitness apps) which may increase the reinforcing value of physical activity, prior research has indicated that there is not a significant relationship between total cell phone use and physical activity. We hypothesize a similarly non-significant relationship in the present study as well.

• While we do not hypothesize a relationship between cell phone use and physical activity we do hypothesize that cell phone use will be positively related to the interaction of physical activity and sedentary behavior (i.e., the “active couch potato” phenomenon). High cell phone users likely utilize their devices to access a wide variety of functions. Within these functions are both those that promote sedentary behavior and those that may promote physical activity. Therefore, it is possible that the highest cell phone users may be regularly accessing both the low-“cost,” reinforcing, screen-based, sedentary activities and those which may increase an individual's motivation to be physically active. In other words, cell phone use will be related to the risk of being an “active couch potato.”