Background: Office-working adults represent an at-risk population for high levels of sedentary behaviour (SB), which has been associated with an increased risk for numerous chronic diseases. This study examined the effectiveness of a Health Action Process Approach (HAPA) based planning intervention augmented with tailored text messages to reduce workplace sitting time (primary outcome) and increase specific non-SBs (i.e. standing time, walking time, stretching time, break frequency, break duration). A secondary purpose was to examine relationships among HAPA volitional constructs and sedentary and non-SBs.
Methods: Full-time office workers (Mage = 45.18 ± 11.33 years) from Canada were randomised into either a HAPA intervention (n = 29) or control (n = 31) condition. Workplace sitting time, time spent in specific non-SBs, and HAPA volitional constructs were assessed at baseline, weeks 2, 4, 6 (post-intervention), and 8 (follow-up).
Results: Significant group by time interaction effects, that favoured the intervention group, were found for sitting time (p = .003, ɳp2 = .07), standing time (p = .019, ɳp2 = .05), and stretching time (p = .001, ɳp2 = .08) as well as for action planning (p < .001, ɳp2 = .20), coping planning (p < .001, ɳp2 = .18), and action control (p < .001, ɳp2 = .15). Significant correlations (p < .05) were also found between the HAPA constructs and time spent sitting, standing, walking, as well as break frequency.
Conclusions: Augmenting a HAPA-based planning intervention with text messages can reduce workplace sitting time in office workers.
Trial registration: ClinicalTrials.gov identifier: NCT03461926.
Keywords: health action process approach; intervention; sedentary behaviour; text messages; workplace.
© 2020 International Association of Applied Psychology.