Doctor of Philosophy
Sedentary behaviour (SB) is positively associated with all-cause mortality, as well as numerous chronic diseases, including fatal and non-fatal cardiovascular disease, type 2 diabetes, certain types of cancer, and metabolic syndrome. Interventions targeting reductions in sedentary time among office workers who are an at-risk population for high levels of SB are needed. The main objective of this dissertation was to contribute to the body of knowledge surrounding theory-based behavioural interventions targeting SB among office working adults. First, a systematic review of the literature (study 1, chapter 2) was conducted that highlighted important cognitive and motivational factors associated with SB, which should be targeted in theory-based interventions designed to reduce SB. Using the motivational phase of the Health Action Process Approach (HAPA), a randomized controlled trial (RCT – study 2, chapter 3) demonstrated that SB and diabetes information can be a meaningful source of motivation among preintender office workers (n = 96). Those in the intervention reported significantly higher intentions for reducing daily sedentary time (ps ≤ .05, ɳp2 values ≥ .08) than their control counterparts. Using the volitional phase of the HAPA, a subsequent RCT (study 3, chapter 4) showed that action and coping planning, augmented with tailored text messages reduced workplace sitting time and increased specific non-SBs in office workers (n = 60). Relative to the controls, participants who received the intervention reported significantly greater reductions in time spent sitting (87.54 min/workday) and accompanying increases in time spent standing (32.56 min/workday) and stretching (11.34 min/workday) at work over an 8-week period (ps < .05, ɳp2 range = .05-.08). Finally, study 3 (chapter 4) also revealed that the intervention targeting reductions in SB can lead to significant improvements in office workers’ perceived emotional well-being and role limitations due to emotional health problems (ps < .05, ɳp2 range = .08-.10). Avenues for future research will be discussed.
Summary for Lay Audience
Too much sitting is related to premature death, as well as numerous chronic diseases, including fatal and non-fatal heart disease, type 2 diabetes, certain types of cancer, and metabolic problems. Strategies to reduce sitting time among office workers who are an at-risk population for high levels of sitting are needed. The main objective of this dissertation was to contribute to the body of knowledge surrounding theory-based health promotion strategies targeting sitting time among office working adults. First, the literature on whether cognitive and motivational factors (i.e., attitudes, social norms, confidence, intentions, habits, values) influence sitting time was examined (study 1, chapter 2). Findings highlighted important cognitive and motivational factors that are related to how much time individuals spend sitting, which should be targeted in health promotion efforts to reduce sitting. Using a prominent health promotion theory, study 2 (chapter 3) demonstrated that health and diabetes information related to too much sitting can motivate office workers to reduce their daily sitting time. Then, study 3 (chapter 4) showed that providing office workers with a counselling session (encouraging them to form individualized plans to reduce their sitting time), followed by daily text messages is an effective strategy to reduce workplace sitting time and increase time spent standing, and stretching in office workers. Finally, study 3 (chapter 4) also revealed that reductions in sitting time can lead to improvements in office workers’ perceived emotional well-being and role limitations due to emotional health problems.
Rollo, Andrew Scott, "Using the Health Action Process Approach (HAPA) to understand and change sedentary behaviour in office workers: Effects on motivation, behaviour, and health outcomes" (2019). Electronic Thesis and Dissertation Repository. 6393.