Abstract
Background: Social media are increasingly being used by young adults worldwide. The question is whether they can be successfully incorporated into health programmes to promote physical activity. Aims: To measure the effect of a WhatsApp-based intervention for promoting physical activity among female college students in Abha, Saudi Arabia. Methods: This randomized controlled trial from November 2019 to January 2020 included 110 students. The intervention group received a brief orientation on exercise and up to 4 physical activity promotion messages per week via WhatsApp for 10 weeks. The messages were obtained from the websites of the US Centers for Disease Control and World Health Or-ganization (WHO). Physical activity was assessed at baseline and at 10-weeks' follow-up using the WHO Global Physical Activity Questionnaire. Results: The 2 groups were similar in sociodemographic and baseline physical activity levels. Postintervention data anal-ysis revealed significant improvement in the proportion of participants with moderate-intensity physical activity in the work and recreation domains. Compared with the control group, mean metabolic equivalents/week of the intervention group improved significantly. The mean difference in total physical activity before and after intervention was significant in all domains and in all categories of activity. The proportion of participants who met the WHO criteria for minimum physical activity per week increased from 69.8% to 90.5% after intervention. Conclusion: Social-network-based interventions improve physical activity and may be incorporated into youth-targeted health programmes.