- Email: [email protected]
Challenging the Dual-Hinge Approach to Intervening on Sedentary Behavior
CURRENT ISSUE
Challenging the Dual-Hinge Approach to Intervening on Sedentary Behavior John C. Spence, PhD,1 Ryan E. Rhodes, PhD,2 Valerie Carson, PhD1
T
he recent recognition that sedentary behavior (SB) is distinct from physical activity (PA), both in terms of determinants1 and health impact,2 is perhaps one of the more remarkable public health zeitgeists of the past 50 years. Basically, it is possible for an individual to engage in high amounts of moderate to vigorous physical activity (MVPA) and remain sedentary for long periods of time.3 For example, the average Canadian adult accumulates approximately 24 minutes of MVPA and sits for 580 minutes, or 69%, of their waking day.4 To address the negative health effects associated with excessive SB, the solution is to decrease the frequency and duration that people are sedentary throughout the day. Thus, more attention is now being focused on the nature and determinants of SB with the intent to develop and implement effective interventions.5 In this paper, some challenges and theoretic complexities of changing SB are identified, especially when substituting with MVPA. Traditionally, SB has been defined by the types of behaviors people do while expending low levels of energy (e.g., watching TV, reading, driving a motor vehicle). However, a recent consensus statement recommended that SB be defined as “any waking behaviour characterized by an energy expenditure r1.5 METs while in a sitting or reclining posture.”6 For instance, a person who is standing but expending o1.5 METs would not be considered sedentary. Thus, posture (sitting or reclining) and level of energy expenditure combined are the defining factors of SB. Marshall and Merchant5 refer to these as behavioral topography (i.e., posture allocation) and metabolic rate. They also point out that behaviors with the same behavioral topographies can serve different roles by type (e.g., sitting playing computer games versus sitting at school). The effectiveness of interventions to reduce SB likely varies by age group and type of behavior. In children and adolescents, small effects are observed across studies that focus primarily on changing TV or screen time behaviors.7 The authors of this review attribute the limited impact of interventions to the habitual component of screen time consumption, the strong effect of environmental cues, and the difficulty of changing multiple types of behavior (e.g.,
computer use, TV viewing) in one intervention. For adults, SB-specific interventions (e.g., reducing sitting time), primarily in the workplace, have more impact (–91 minutes of sedentary time) than those that attempt to substitute SB with MVPA (–19 minutes of sedentary time).8 Thus, it appears that standing interventions in the workplace have more potential for impact on SB than do screen time interventions with children and adolescents. Although interventions are proceeding, and have shown some impact, it is clear that existing understanding of the determinants of SB as recently defined6 is limited. In spite of the fact that some recent studies have adopted theory to guide their interventions,9 Biddle10 decries the lack of psychological research on SB. More specifically, Salmon and colleagues11 have called for the “application and development of behavioral theories for sedentary behavior.” That is, further insight is required on the psychology of sitting, the powerful reinforcing properties of favorite sedentary past times, and the environmental cues and policies that regulate behavior in certain settings. Owen et al.1 describe a behavior-settings perspective on SB in the form of an ecological model. It places an emphasis on settings and context and behavioral specificity. Although they state that constructs from other theories typically used for PA could be employed within their model to guide SB interventions (e.g., social cognitive theory), they do acknowledge that it provides “broad guidance,” which is usually the case for ecological models. However, the usefulness of other theoretic approaches apart from the social cognitive theories that have dominated health behavior research for the past couple of decades should be explored.11 More so than PA, it is likely that unconscious processes (e.g., automatic processes, implicit attitudes, habit) are integral factors for much of From the 1Faculty of Physical Education and Recreation, University of Alberta, Edmonton, Alberta, Canada; and 2School of Exercise Science, Physical and Health Education, University of Victoria, Victoria, British Columbia, Canada Address correspondence to: John C. Spence, PhD, Sedentary Living Lab, Faculty of Physical Education and Recreation, University of Alberta, Van Vliet Complex, Edmonton, Alberta T6G 2H9. E-mail: [email protected]. 0749-3797/$36.00 http://dx.doi.org/10.1016/j.amepre.2016.10.019
& 2016 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.
Am J Prev Med 2016;](]):]]]–]]] 1
2
Spence et al / Am J Prev Med 2016;](]):]]]–]]] 12
SB. At the same time, perceptions of competence and capability (e.g., self-efficacy) will be less relevant, whereas hedonic factors (e.g., enjoyment) will be important for understanding discretionary SB. In the absence of relevant theories and models to describe, explain, and predict SB in interventions, it is likely researchers and practitioners will continue to adapt those that have been employed to varying degrees of success in the area of PA. Part of the reason for this malaise is that the nature of the behavior has been poorly articulated.13 The recent consensus statement providing a clear and universal definition of SB6 is a starting point. However, the waters are still being muddied by an overfocus in SB interventions on substituting the type of behavior (e.g., playing video games) with another that involves MVPA, as opposed to altering behavioral topography (i.e., standing) and perhaps increasing light PA. If the type of SB is the target of an intervention, then the relevant behavioral antecedents and mechanisms likely will be different from those associated with behavioral topography. Furthermore, substituting SB with MVPA engages two behavioral systems by removing one and promoting another; the authors call this the dual-hinge approach. Thus, a substitution-based intervention will be more challenging than getting able-bodied people to stand up while continuing to engage in their favored (e.g., watching TV) or required behavior (e.g., computer at work). In the following, this distinction between posturaland substitution-based SB interventions is discussed further, and framed in the capability, opportunity, motivation (COM-B) system13 to identify potential theories or constructs that would be useful for each approach.
CAPABILITY Capability involves both physical (e.g., skills) and psychological (e.g., knowledge) capacity to engage in a particular behavior.13 In the context of SB, for an able-bodied person to stand up requires no skill. Whereas, participating in a more complex behavior such as MVPA requires varying degrees of skill depending on the type of activity (e.g., walking versus swimming). Regardless, most people remain unaware of the negative health effects of sitting independent of MVPA. Thus, education-based interventions could be effective in promoting a simple change in behavior such as increased standing.14 Ultimately, capability will not be a limiting factor for postural-based interventions, but could restrict the effectiveness of behavioral substitutions.
OPPORTUNITY It is likely that SB is heavily influenced by physical and social environments in which humans exist.1 For
instance, engagement in passive forms of transportation, work, and recreation is dictated to some extent by one’s physical surroundings. Furthermore, norms, practices, and policies reinforce a sedentary lifestyle. In fact, much of non-discretionary time may be spent in settings where limited choice exists about whether people can move around or not (e.g., classrooms, meetings or other duties in the workplace, commuting by car). Thus, potential interventions require some changes to the physical environment (e.g., offering standing desks, constructing bicycle lanes) and provision of social support. A recent review showed that environmental restructuring was the only effective opportunity-related intervention to reduce sitting time, primarily through the provision of sit–stand desks.14 Given the strong reinforcing and restrictive properties of the physical and social environments, substituting a type of SB (e.g., playing video games, sitting at the computer at work) with MVPA will be difficult. By contrast, a standing intervention would not interfere with these favored or required tasks and may only require some environmental restructuring and education to challenge norms. In sum, reducing SB by manipulating the environment will be easier if the target behavior is reduced sitting (frequency, duration), and perhaps increased light PA, as opposed to invoking the dual-hinge by replacing with MVPA.
MOTIVATION Motivation, which in the COM-B system is defined broadly to include implicit/reflexive (e.g., habits, impulses) and explicit/reflective (e.g., intention, attitude) determinants of behavior,13 may represent the largest hurdle to substitution-based behavior change. First, one needs to consider the ingrained and likely powerful motivational elements of SB, which appear to include habitual12 and intentional elements with a strong attitudinal and hedonic base (i.e., affect). SB, particularly discretionary, is thus highly reinforced by cues and practiced routine, and paired with anticipated pleasure and planned behavior. Such behavior neither represents mere incidental behaviors or entirely rational ones. Commensurate with this wide range of motivational properties, SB change strategies in the motivational domain are layered and comprise some aspect of the full behavior change taxonomy.14 Therefore, reducing the motivation for certain types of SB is likely a difficult task.7 Assuming SB motivation has been reduced in an intervention, one then needs to simultaneously increase motivation for the type of PA under substitution. Although PA has some evidence for implicit/automatic motivation,15 it has been traditionally studied with social www.ajpmonline.org
Spence et al / Am J Prev Med 2016;](]):]]]–]]]
cognitive approaches that emphasize motivation from long-term health outcomes and subsequent planned behavior. Further, contrary to prevalent discretionary SB, physical inactivity is often marked by a failure to instill a strong hedonic basis of motivation and thus creates a gap between PA intentions and behavior.16 The complexity of PA motivation and subsequent attempts to intervene is now a longstanding area of research. Unsurprisingly, the effectiveness of changing PA motivation has been very modest.17 Therefore, increasing PA motivation is extremely challenging, independent of attempts to change SB. Because SB interventions are still in their infancy, limited experimental evidence exists to examine motivational mediators of substitution-based research. Observational research, however, has shown that leisure-time SB motivation, particularly screen viewing, conflicts with MVPA in adult populations.18 Thus, goal conflict may exist within these motivational systems that further challenge interventions set on demotivating SB while attempting to increase motivation for MVPA. Although no direct evidence for motivational mediators is available, this may also explain why substitution interventions to reduce SB in the home have been a challenge.7 Thus, evidence so far supports the hypothesis that SB substitution with MVPA is difficult owing to the two motivational systems one must intervene upon. By contrast, asking a person to stand while continuing to engage in their task of choice (e.g., reading) will not arouse a second motivational system.
3
Still, with SB research in its infancy, several areas require research to examine the worthiness of these approaches. For instance, the application of SB and PA mediators to test these processes on intervention–behavior relationships is an essential next step. Continued refinement of SB theory is required and a broad array of variables should be considered, inclusive of the hedonic and implicit aspects of SB. Examination of the upscaling potential of these two intervention approaches is also needed. PA interventions thus far have had difficulty in gaining traction at the population level. But, postural change interventions that avoid having to intervene upon the motivational systems of two behaviors should have far easier scale-up than behavioral substitution, but this requires assessment. Finally, to comprehend the healthderived benefits of doses of substitution compared with topographical interventions, it is imperative to identify the compositional elements of different types of PA versus SB on health outcomes.20 For instance, standing interventions may be more effective in decreasing SB, but substitution-based interventions may result in more significant health benefits. Such clarification is necessary to guide the recommended SB changes within interventions and, given the differences in energy expenditure between standing and MVPA, may require different intervention approaches. Regardless, those attempting to intervene on SB should be clear on the target behavior (e.g., reducing sitting time) and be aware of the complexities associated with substituting SB with MVPA.
ACKNOWLEDGMENTS FUTURE DIRECTIONS Now with a clear definition of SB,6 two types of interventions are possible. One can substitute SB with a different behavior that involves some type of MVPA (e.g., swimming laps), or alter behavioral topography (e.g., from sitting to standing) while continuing with the original activity (e.g., standing while watching TV or working). Based on the complexity of intervening on two behavioral systems and their corresponding aspects of capability, opportunity, and motivation,13 the logical deduction is that behavioral substitution will likely be less effective at reducing SB than changes in behavioral topography. Early evidence of the effectiveness of SB interventions that employ postural change compared with substitution behavior interventions8,14 also supports this argument. This is not to say that all dual-hinge interventions will be ineffective, especially if they incorporate environmental cues, or simple manipulations of the environment, and do not require substantial shifts from favored types of SB to MVPA.19 ] 2016
No financial disclosures were reported by the authors of this paper.
REFERENCES 1. Owen N, Sugiyama T, Eakin EE, Gardiner PA, Tremblay MS, Sallis JF. Adults’ sedentary behavior—determinants and interventions. Am J Prev Med. 2011;41(2):189–196. http://dx.doi.org/10.1016/j.amepre. 2011.05.013. 2. Hamilton MT, Healy GN, Dunstan DW, Zderic TW, Owen N. Too little exercise and too much sitting: Inactivity physiology and the need for new recommendations on sedentary behavior. Curr Cardiovasc Risk Rep. 2008;2(4):292–298. http://dx.doi.org/10.1007/s12170-0080054-8. 3. Craft L, Zderic TW, Gapstur SM, et al. Evidence that women meeting physical activity guidelines do not sit less: an observational inclinometry study. Int J Behav Nutr Phys Act. 2012;9:122. http://dx.doi.org/ 10.1186/1479-5868-9-122. 4. Colley RC, Garriguet D, Janssen I, Craig CL, Clarke J, Tremblay MS. Physical activity of Canadian adults: accelerometer results from the 2007 to 2009 Canadian Health Measures Survey. Health Rep. 2011;22 (1):7–14. 5. Marshall SJ, Merchant G. Advancing the science of sedentary behavior measurement. Am J Prev Med. 2013;44(2):190–191. http://dx.doi.org/ 10.1016/j.amepre.2012.11.001.
4
Spence et al / Am J Prev Med 2016;](]):]]]–]]]
6. Sedentary Behaviour Research Network. Letter to the editor: Standardized use of the terms “sedentary” and “sedentary behaviours.” App Physiol Nutr Metab. 2012;37(3):540–542. http://dx.doi.org/10.1139/h2012-024. 7. Biddle SJH, O’Connell S, Braithwaite RE. Sedentary behaviour interventions in young people: a meta-analysis. Br J Sports Med. 2011;45:937–942. http://dx.doi.org/10.1136/bjsports-2011-090205. 8. Prince SA, Saunders TJ, Gresty K, Reid RD. A comparison of the effectiveness of physical activity and sedentary behaviour interventions in reducing sedentary time in adults: a systematic review and metaanalysis of controlled trials. Obes Rev. 2014;15(11):905–919. http://dx. doi.org/10.1111/obr.12215. 9. Carr L, Leonhard C, Tucker S, Fethke N, Benzo R, Gerr F. Total worker health intervention increases activity of sedentary workers. Am J Prev Med. 2016;50(1):9–17. http://dx.doi.org/10.1016/j.amepre.2015.06.022. 10. Biddle SJH. Fit or sit? Is there a psychology of sedentary behaviour? Sport Exerc Psychol Rev. 2011;7(2):5–10. 11. Salmon J, Tremblay MS, Marshall SJ, Hume C. Health risks, correlates, and interventions to reduce sedentary behavior in young people. Am J Prev Med. 2011;41(2):197–206. http://dx.doi.org/10.1016/j.amepre.2011.05.001. 12. Conroy DE, Maher JP, Elavsky S, Hyde AL, Doerksen SE. Sedentary behavior as a daily process regulated by habits and intentions. Health Psychol. 2013;32(11):1149–1157. http://dx.doi.org/10.1037/a0031629. 13. Michie S, van Stralen MM, West R. The Behaviour Change Wheel: a new method for characterising and designing behaviour change interventions. Implement Sci. 2011;6:42. http://dx.doi.org/10.1186/ 1748-5908-6-42. 14. Gardner B, Smith L, Lorencatto F, Hamer M, Biddle SJH. How to reduce sitting time? A review of behaviour change strategies used in
15.
16.
17.
18.
19.
20.
sedentary behaviour reduction interventions among adults. Health Psychol Rev. 2016;10(1):89–112. http://dx.doi.org/10.1080/17437199. 2015.1082146. Rebar A, Rhodes RE, Vandelanotte C, Kates A, Dimmock J, Jackson B. A systematic review of non-conscious regulatory processes and physical activity. Health Psychol Rev. In press. Online May 20, 2016. http://dx.doi.org/10.1080/17437199.2016.1183505. Rhodes RE, Kates A. Can the affective response to exercise predict future motives and physical activity behavior? A systematic review of published evidence. Ann Behav Med. 2015;49(5):715–731. http://dx. doi.org/10.1007/s12160-015-9704-5. Prestwich A, Sniehotta FF, Whittington C, Dombrowski SU, Rogers L, Michie S. Does theory influence the effectiveness of health behavior interventions? Meta-analysis. Health Psychol. 2014;33(5):465–474. http://dx.doi.org/10.1037/a0032853. Rhodes RE, Blanchard CM. Do sedentary motives adversely affect physical activity? Adding cross-behavioural cognitions to the theory of planned behaviour. Psychol Health. 2008;23(7):789–805. http://dx.doi. org/10.1080/08870440701421578. Bond DS, Thomas JG, Raynor HA, et al. B-MOBILE—a smartphonebased intervention to reduce sedentary time in overweight/obese individuals: a within-subjects experimental trial. PLoS One. 2014;9 (6):e100821. http://dx.doi.org/10.1371/journal.pone.0100821. Chastin SFM, Palarea-Albaladejo J, Dontje ML, Skelton DA. Combined effects of time spent in physical activity, sedentary behaviors and sleep on obesity and cardio-metabolic health markers: a novel compositional data analysis approach. PLoS One. 2015;10(10):e0139984. http://dx.doi. org/10.1371/journal.pone.0139984.
www.ajpmonline.org
Challenging the Dual-Hinge Approach to Intervening on Sedentary Behavior John C. Spence, PhD,1 Ryan E. Rhodes, PhD,2 Valerie Carson, PhD1
T
he recent recognition that sedentary behavior (SB) is distinct from physical activity (PA), both in terms of determinants1 and health impact,2 is perhaps one of the more remarkable public health zeitgeists of the past 50 years. Basically, it is possible for an individual to engage in high amounts of moderate to vigorous physical activity (MVPA) and remain sedentary for long periods of time.3 For example, the average Canadian adult accumulates approximately 24 minutes of MVPA and sits for 580 minutes, or 69%, of their waking day.4 To address the negative health effects associated with excessive SB, the solution is to decrease the frequency and duration that people are sedentary throughout the day. Thus, more attention is now being focused on the nature and determinants of SB with the intent to develop and implement effective interventions.5 In this paper, some challenges and theoretic complexities of changing SB are identified, especially when substituting with MVPA. Traditionally, SB has been defined by the types of behaviors people do while expending low levels of energy (e.g., watching TV, reading, driving a motor vehicle). However, a recent consensus statement recommended that SB be defined as “any waking behaviour characterized by an energy expenditure r1.5 METs while in a sitting or reclining posture.”6 For instance, a person who is standing but expending o1.5 METs would not be considered sedentary. Thus, posture (sitting or reclining) and level of energy expenditure combined are the defining factors of SB. Marshall and Merchant5 refer to these as behavioral topography (i.e., posture allocation) and metabolic rate. They also point out that behaviors with the same behavioral topographies can serve different roles by type (e.g., sitting playing computer games versus sitting at school). The effectiveness of interventions to reduce SB likely varies by age group and type of behavior. In children and adolescents, small effects are observed across studies that focus primarily on changing TV or screen time behaviors.7 The authors of this review attribute the limited impact of interventions to the habitual component of screen time consumption, the strong effect of environmental cues, and the difficulty of changing multiple types of behavior (e.g.,
computer use, TV viewing) in one intervention. For adults, SB-specific interventions (e.g., reducing sitting time), primarily in the workplace, have more impact (–91 minutes of sedentary time) than those that attempt to substitute SB with MVPA (–19 minutes of sedentary time).8 Thus, it appears that standing interventions in the workplace have more potential for impact on SB than do screen time interventions with children and adolescents. Although interventions are proceeding, and have shown some impact, it is clear that existing understanding of the determinants of SB as recently defined6 is limited. In spite of the fact that some recent studies have adopted theory to guide their interventions,9 Biddle10 decries the lack of psychological research on SB. More specifically, Salmon and colleagues11 have called for the “application and development of behavioral theories for sedentary behavior.” That is, further insight is required on the psychology of sitting, the powerful reinforcing properties of favorite sedentary past times, and the environmental cues and policies that regulate behavior in certain settings. Owen et al.1 describe a behavior-settings perspective on SB in the form of an ecological model. It places an emphasis on settings and context and behavioral specificity. Although they state that constructs from other theories typically used for PA could be employed within their model to guide SB interventions (e.g., social cognitive theory), they do acknowledge that it provides “broad guidance,” which is usually the case for ecological models. However, the usefulness of other theoretic approaches apart from the social cognitive theories that have dominated health behavior research for the past couple of decades should be explored.11 More so than PA, it is likely that unconscious processes (e.g., automatic processes, implicit attitudes, habit) are integral factors for much of From the 1Faculty of Physical Education and Recreation, University of Alberta, Edmonton, Alberta, Canada; and 2School of Exercise Science, Physical and Health Education, University of Victoria, Victoria, British Columbia, Canada Address correspondence to: John C. Spence, PhD, Sedentary Living Lab, Faculty of Physical Education and Recreation, University of Alberta, Van Vliet Complex, Edmonton, Alberta T6G 2H9. E-mail: [email protected]. 0749-3797/$36.00 http://dx.doi.org/10.1016/j.amepre.2016.10.019
& 2016 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.
Am J Prev Med 2016;](]):]]]–]]] 1
2
Spence et al / Am J Prev Med 2016;](]):]]]–]]] 12
SB. At the same time, perceptions of competence and capability (e.g., self-efficacy) will be less relevant, whereas hedonic factors (e.g., enjoyment) will be important for understanding discretionary SB. In the absence of relevant theories and models to describe, explain, and predict SB in interventions, it is likely researchers and practitioners will continue to adapt those that have been employed to varying degrees of success in the area of PA. Part of the reason for this malaise is that the nature of the behavior has been poorly articulated.13 The recent consensus statement providing a clear and universal definition of SB6 is a starting point. However, the waters are still being muddied by an overfocus in SB interventions on substituting the type of behavior (e.g., playing video games) with another that involves MVPA, as opposed to altering behavioral topography (i.e., standing) and perhaps increasing light PA. If the type of SB is the target of an intervention, then the relevant behavioral antecedents and mechanisms likely will be different from those associated with behavioral topography. Furthermore, substituting SB with MVPA engages two behavioral systems by removing one and promoting another; the authors call this the dual-hinge approach. Thus, a substitution-based intervention will be more challenging than getting able-bodied people to stand up while continuing to engage in their favored (e.g., watching TV) or required behavior (e.g., computer at work). In the following, this distinction between posturaland substitution-based SB interventions is discussed further, and framed in the capability, opportunity, motivation (COM-B) system13 to identify potential theories or constructs that would be useful for each approach.
CAPABILITY Capability involves both physical (e.g., skills) and psychological (e.g., knowledge) capacity to engage in a particular behavior.13 In the context of SB, for an able-bodied person to stand up requires no skill. Whereas, participating in a more complex behavior such as MVPA requires varying degrees of skill depending on the type of activity (e.g., walking versus swimming). Regardless, most people remain unaware of the negative health effects of sitting independent of MVPA. Thus, education-based interventions could be effective in promoting a simple change in behavior such as increased standing.14 Ultimately, capability will not be a limiting factor for postural-based interventions, but could restrict the effectiveness of behavioral substitutions.
OPPORTUNITY It is likely that SB is heavily influenced by physical and social environments in which humans exist.1 For
instance, engagement in passive forms of transportation, work, and recreation is dictated to some extent by one’s physical surroundings. Furthermore, norms, practices, and policies reinforce a sedentary lifestyle. In fact, much of non-discretionary time may be spent in settings where limited choice exists about whether people can move around or not (e.g., classrooms, meetings or other duties in the workplace, commuting by car). Thus, potential interventions require some changes to the physical environment (e.g., offering standing desks, constructing bicycle lanes) and provision of social support. A recent review showed that environmental restructuring was the only effective opportunity-related intervention to reduce sitting time, primarily through the provision of sit–stand desks.14 Given the strong reinforcing and restrictive properties of the physical and social environments, substituting a type of SB (e.g., playing video games, sitting at the computer at work) with MVPA will be difficult. By contrast, a standing intervention would not interfere with these favored or required tasks and may only require some environmental restructuring and education to challenge norms. In sum, reducing SB by manipulating the environment will be easier if the target behavior is reduced sitting (frequency, duration), and perhaps increased light PA, as opposed to invoking the dual-hinge by replacing with MVPA.
MOTIVATION Motivation, which in the COM-B system is defined broadly to include implicit/reflexive (e.g., habits, impulses) and explicit/reflective (e.g., intention, attitude) determinants of behavior,13 may represent the largest hurdle to substitution-based behavior change. First, one needs to consider the ingrained and likely powerful motivational elements of SB, which appear to include habitual12 and intentional elements with a strong attitudinal and hedonic base (i.e., affect). SB, particularly discretionary, is thus highly reinforced by cues and practiced routine, and paired with anticipated pleasure and planned behavior. Such behavior neither represents mere incidental behaviors or entirely rational ones. Commensurate with this wide range of motivational properties, SB change strategies in the motivational domain are layered and comprise some aspect of the full behavior change taxonomy.14 Therefore, reducing the motivation for certain types of SB is likely a difficult task.7 Assuming SB motivation has been reduced in an intervention, one then needs to simultaneously increase motivation for the type of PA under substitution. Although PA has some evidence for implicit/automatic motivation,15 it has been traditionally studied with social www.ajpmonline.org
Spence et al / Am J Prev Med 2016;](]):]]]–]]]
cognitive approaches that emphasize motivation from long-term health outcomes and subsequent planned behavior. Further, contrary to prevalent discretionary SB, physical inactivity is often marked by a failure to instill a strong hedonic basis of motivation and thus creates a gap between PA intentions and behavior.16 The complexity of PA motivation and subsequent attempts to intervene is now a longstanding area of research. Unsurprisingly, the effectiveness of changing PA motivation has been very modest.17 Therefore, increasing PA motivation is extremely challenging, independent of attempts to change SB. Because SB interventions are still in their infancy, limited experimental evidence exists to examine motivational mediators of substitution-based research. Observational research, however, has shown that leisure-time SB motivation, particularly screen viewing, conflicts with MVPA in adult populations.18 Thus, goal conflict may exist within these motivational systems that further challenge interventions set on demotivating SB while attempting to increase motivation for MVPA. Although no direct evidence for motivational mediators is available, this may also explain why substitution interventions to reduce SB in the home have been a challenge.7 Thus, evidence so far supports the hypothesis that SB substitution with MVPA is difficult owing to the two motivational systems one must intervene upon. By contrast, asking a person to stand while continuing to engage in their task of choice (e.g., reading) will not arouse a second motivational system.
3
Still, with SB research in its infancy, several areas require research to examine the worthiness of these approaches. For instance, the application of SB and PA mediators to test these processes on intervention–behavior relationships is an essential next step. Continued refinement of SB theory is required and a broad array of variables should be considered, inclusive of the hedonic and implicit aspects of SB. Examination of the upscaling potential of these two intervention approaches is also needed. PA interventions thus far have had difficulty in gaining traction at the population level. But, postural change interventions that avoid having to intervene upon the motivational systems of two behaviors should have far easier scale-up than behavioral substitution, but this requires assessment. Finally, to comprehend the healthderived benefits of doses of substitution compared with topographical interventions, it is imperative to identify the compositional elements of different types of PA versus SB on health outcomes.20 For instance, standing interventions may be more effective in decreasing SB, but substitution-based interventions may result in more significant health benefits. Such clarification is necessary to guide the recommended SB changes within interventions and, given the differences in energy expenditure between standing and MVPA, may require different intervention approaches. Regardless, those attempting to intervene on SB should be clear on the target behavior (e.g., reducing sitting time) and be aware of the complexities associated with substituting SB with MVPA.
ACKNOWLEDGMENTS FUTURE DIRECTIONS Now with a clear definition of SB,6 two types of interventions are possible. One can substitute SB with a different behavior that involves some type of MVPA (e.g., swimming laps), or alter behavioral topography (e.g., from sitting to standing) while continuing with the original activity (e.g., standing while watching TV or working). Based on the complexity of intervening on two behavioral systems and their corresponding aspects of capability, opportunity, and motivation,13 the logical deduction is that behavioral substitution will likely be less effective at reducing SB than changes in behavioral topography. Early evidence of the effectiveness of SB interventions that employ postural change compared with substitution behavior interventions8,14 also supports this argument. This is not to say that all dual-hinge interventions will be ineffective, especially if they incorporate environmental cues, or simple manipulations of the environment, and do not require substantial shifts from favored types of SB to MVPA.19 ] 2016
No financial disclosures were reported by the authors of this paper.
REFERENCES 1. Owen N, Sugiyama T, Eakin EE, Gardiner PA, Tremblay MS, Sallis JF. Adults’ sedentary behavior—determinants and interventions. Am J Prev Med. 2011;41(2):189–196. http://dx.doi.org/10.1016/j.amepre. 2011.05.013. 2. Hamilton MT, Healy GN, Dunstan DW, Zderic TW, Owen N. Too little exercise and too much sitting: Inactivity physiology and the need for new recommendations on sedentary behavior. Curr Cardiovasc Risk Rep. 2008;2(4):292–298. http://dx.doi.org/10.1007/s12170-0080054-8. 3. Craft L, Zderic TW, Gapstur SM, et al. Evidence that women meeting physical activity guidelines do not sit less: an observational inclinometry study. Int J Behav Nutr Phys Act. 2012;9:122. http://dx.doi.org/ 10.1186/1479-5868-9-122. 4. Colley RC, Garriguet D, Janssen I, Craig CL, Clarke J, Tremblay MS. Physical activity of Canadian adults: accelerometer results from the 2007 to 2009 Canadian Health Measures Survey. Health Rep. 2011;22 (1):7–14. 5. Marshall SJ, Merchant G. Advancing the science of sedentary behavior measurement. Am J Prev Med. 2013;44(2):190–191. http://dx.doi.org/ 10.1016/j.amepre.2012.11.001.
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Spence et al / Am J Prev Med 2016;](]):]]]–]]]
6. Sedentary Behaviour Research Network. Letter to the editor: Standardized use of the terms “sedentary” and “sedentary behaviours.” App Physiol Nutr Metab. 2012;37(3):540–542. http://dx.doi.org/10.1139/h2012-024. 7. Biddle SJH, O’Connell S, Braithwaite RE. Sedentary behaviour interventions in young people: a meta-analysis. Br J Sports Med. 2011;45:937–942. http://dx.doi.org/10.1136/bjsports-2011-090205. 8. Prince SA, Saunders TJ, Gresty K, Reid RD. A comparison of the effectiveness of physical activity and sedentary behaviour interventions in reducing sedentary time in adults: a systematic review and metaanalysis of controlled trials. Obes Rev. 2014;15(11):905–919. http://dx. doi.org/10.1111/obr.12215. 9. Carr L, Leonhard C, Tucker S, Fethke N, Benzo R, Gerr F. Total worker health intervention increases activity of sedentary workers. Am J Prev Med. 2016;50(1):9–17. http://dx.doi.org/10.1016/j.amepre.2015.06.022. 10. Biddle SJH. Fit or sit? Is there a psychology of sedentary behaviour? Sport Exerc Psychol Rev. 2011;7(2):5–10. 11. Salmon J, Tremblay MS, Marshall SJ, Hume C. Health risks, correlates, and interventions to reduce sedentary behavior in young people. Am J Prev Med. 2011;41(2):197–206. http://dx.doi.org/10.1016/j.amepre.2011.05.001. 12. Conroy DE, Maher JP, Elavsky S, Hyde AL, Doerksen SE. Sedentary behavior as a daily process regulated by habits and intentions. Health Psychol. 2013;32(11):1149–1157. http://dx.doi.org/10.1037/a0031629. 13. Michie S, van Stralen MM, West R. The Behaviour Change Wheel: a new method for characterising and designing behaviour change interventions. Implement Sci. 2011;6:42. http://dx.doi.org/10.1186/ 1748-5908-6-42. 14. Gardner B, Smith L, Lorencatto F, Hamer M, Biddle SJH. How to reduce sitting time? A review of behaviour change strategies used in
15.
16.
17.
18.
19.
20.
sedentary behaviour reduction interventions among adults. Health Psychol Rev. 2016;10(1):89–112. http://dx.doi.org/10.1080/17437199. 2015.1082146. Rebar A, Rhodes RE, Vandelanotte C, Kates A, Dimmock J, Jackson B. A systematic review of non-conscious regulatory processes and physical activity. Health Psychol Rev. In press. Online May 20, 2016. http://dx.doi.org/10.1080/17437199.2016.1183505. Rhodes RE, Kates A. Can the affective response to exercise predict future motives and physical activity behavior? A systematic review of published evidence. Ann Behav Med. 2015;49(5):715–731. http://dx. doi.org/10.1007/s12160-015-9704-5. Prestwich A, Sniehotta FF, Whittington C, Dombrowski SU, Rogers L, Michie S. Does theory influence the effectiveness of health behavior interventions? Meta-analysis. Health Psychol. 2014;33(5):465–474. http://dx.doi.org/10.1037/a0032853. Rhodes RE, Blanchard CM. Do sedentary motives adversely affect physical activity? Adding cross-behavioural cognitions to the theory of planned behaviour. Psychol Health. 2008;23(7):789–805. http://dx.doi. org/10.1080/08870440701421578. Bond DS, Thomas JG, Raynor HA, et al. B-MOBILE—a smartphonebased intervention to reduce sedentary time in overweight/obese individuals: a within-subjects experimental trial. PLoS One. 2014;9 (6):e100821. http://dx.doi.org/10.1371/journal.pone.0100821. Chastin SFM, Palarea-Albaladejo J, Dontje ML, Skelton DA. Combined effects of time spent in physical activity, sedentary behaviors and sleep on obesity and cardio-metabolic health markers: a novel compositional data analysis approach. PLoS One. 2015;10(10):e0139984. http://dx.doi. org/10.1371/journal.pone.0139984.
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