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.
Full‐time office workers (M
age = 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).
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.
Augmenting a HAPA‐based planning intervention with text messages can reduce workplace sitting time in office workers.
TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03461926.