RESUMO
Aim: Sedentary behavior is a severe and independent risk factor for health. According to current research, sitting time is at a dangerously high level. Especially young adults show a high prevalence compared to others. The study aimed to assess the effectiveness of a 6-week messenger-based intervention to reduce sedentary behavior in university students. Subject and methods: The 345 university students that enrolled were randomly assigned to the intervention group (n = 173) and control group (n = 172). Randomization and allocation to the trial group were computer assisted. The trial was conducted remotely, without any personal contact. A drop out of 276 participants led to a primary analysis of 71 (IG n = 41; CG n = 31) participants. Sedentary behavior was assessed online using the Heidelberg Questionnaire for the Assessment of Sitting Behavior, at 5 time points: baseline (T0), 2 weeks (Z1), 4 weeks (Z2) 6 weeks (end of the intervention, T1), and follow-up 4 weeks after intervention (T2). Results: Mixed ANOVA was carried out for T0 and T1 to reveal interaction effects between time and group. Mean differences show a highly practically and statistically relevant reduction in sitting time in the intervention group of 60 min between baseline and T1. No sustained effect of the intervention could be detected by analyzing sitting times at follow-up, 4 weeks after the end of the intervention. Conclusions: Reduction in sedentary behavior in the intervention group after 6 weeks shows that the intervention is practically and statistically relevant. Limitations concerning the assessment method (questionnaire) as well as the sample size should be considered. The trial serves as a pilot study. However, the positive outcome of sitting time reduction paves the way for further research in this field. Supplementary Information: The online version contains supplementary material available at 10.1007/s10389-022-01747-7.
