Using Mobile Technology to Reduce Sedentary Time in Employees of a Johannesburg Marketing Company

Abstract

Background: Prolonged sedentary behaviour in the workplace is linked to various adverse health outcomes, including increased cardiometabolic risk and reduced psychological well-being. Office-based employees are particularly vulnerable due to their extended vocational sitting, yet simple and cost-effective interventions remain limited. Aim: This study evaluated the effectiveness of an electronic health (eHealth) intervention by incorporating movement prompts and gain-framed health messages to reduce workplace sedentary behaviour among employees of a marketing and advertising firm in Johannesburg, South Africa. Methods: A mixed-methods approach was used. Twenty-eight participants were assigned to either an intervention group (n=13, mean age 32.46 ±6.04 years), which received hourly movement prompts and weekly health messages designed to encourage more movement during vocational hours and highlight the benefits of decreasing sedentary behaviour, or a control group (n=15, mean age 34.94 ±6.67 years), which used a self-monitoring app. Group allocation was based on smartphone type (iPhone vs Android). Quantitative data were collected via wrist-worn accelerometers, anthropometric and cardiometabolic assessments, self-reported sedentary time and Satisfaction with Life questionnaires. Statistical analysis included descriptive statistics, paired and independent t-tests, change score comparisons, repeated measures analysis of variance (ANOVA), and Pearson’s correlation analysis. Qualitative data were gathered post-intervention through focus group discussions and analysed using reflexive thematic analysis that was guided by Braun and Clarke’s six- step approach, which involved becoming familiar with the data, generating initial codes, identifying and reviewing themes, defining and naming, and then producing the final report. This method was selected for its flexibility and systematic process in exploring participants’ perspectives and identifying patterns within the data. v Results: The intervention group increased their average number of workday breaks from 24.94 ±8.26 to 28.38 ±12.12 breaks per day, while the control group decreased from 30.72 ±12.06 to 25.9 ±9.04 breaks per day (p = 0.04). No significant difference in objectively measured sedentary behaviour was observed between the two groups and across the intervention period. Unexpectedly, diastolic blood pressure increased in the intervention group (81.47 ±10.57 mmHg to 84.54 ±11.27 mmHg), while other cardiometabolic markers, systolic blood pressure, triglycerides, cholesterol, and glucose remained unchanged. Only the intervention group showed an increase in satisfaction with life scores (p = 0.006). The qualitative analysis revealed five main themes, including the impact of the intervention, the role of sedentary behaviour and its impact on overall health, workplace culture and barriers to change, accountability and future recommendations. The qualitative findings highlighted increased awareness of sedentary behaviour and the perceived benefits of reducing prolonged sitting. However, several barriers to adherence were noted, such as workload, office culture, and a limited dedicated movement space, making it difficult to maintain healthy habits. Conclusion: This exploratory study demonstrated that eHealth interventions, such as hourly smartphone prompts, may encourage workplace movement and increase awareness regarding sedentary behaviour. Although the eHealth prompt did not result in significant changes in overall sedentary time or cardiometabolic health, the qualitative findings suggest that the participants became more conscious of their behaviour, health, and accountability. These results highlight that while simple eHealth prompts may have some benefit, they are unlikely to be successful in isolation. Greater support within the workplace may be needed to help sustain long-term behaviour change within the office setting. The findings from this study offer insights that can be utilised to develop more comprehensive workplace health interventions and guide future research.