ESC Project: The Influence of Strangers in Physical Activity Promotion. A Randomized Pilot Trial

Introduction: Notwithstanding the wide spread knowledge about the multiple health benefits associated with regular physical activity (PA), physical inactivity is worrisome and was recently nominated the fourth leading risk factor for global mortality (1). Therefore, programs that promote behavior changes towards PA seem warranted. A rising number of studies have been emerging from Deci and Ryan’s Self Determination Theory with interventions targeting health behavior change (2). Recent research shows that exercise motivation can be ’contagious’ (3). Hence, the main purpose of this pilot study, which was built to test the procedures of a larger trial, was to analyze the association between social contagion through strangers and PA and sedentary behavior (SB) levels.

Methods: A randomized pilot trial was designed, with 16 adults (18-64 years), both genders, with four groups (4 participants each): group 1, primed with a promotional brochure about PA e SB; group 2, primed with strangers doing PA; group 3, primed with strangers in SB; control group, exposed to video about healthy nutrition. Participants PA and SB were measured objectively by accelerometers ActiGraph (GT3X) for seven consecutive days, using a 10-second epoch, before and after the intervention. Cases were included if they had at least two valid days for each wearing week. A valid day had to contain at least 10 valid hours. Data was examined by analysis of variance (ANOVA) with repeated measures.

Results: We found a marginally significant increase in all groups between pre-test and post-test for SB (F=4.37, p=.059). Pre-test and post-test PA differences were not found on moderate (F=.06, p=.814) and vigorous (F=.56, p=.468) intensities. Significant decreases were found on light (F 12.21, p=.004) and lifestyle (F=9.63, p=.009) PA intensities. No differences were found between control and intervention groups.

Discussion: The pilot data seems to indicate that strangers doing PA or in SB do not promote the social contagion for PA and SB in adults. However, this data is preliminary data and more research is in progress.

References: 1. WHO. Global Recommendations on Physical Activity for Health. Genebra: WHO Press. 2010. 2. Fortier MS, Duda JL, Teixeira PJ. Promoting physical activity: development and testing of self-determination theory-based interventions. The international journal of behavioral nutrition and physical activity. 2012;9:20. 3. Scarapicchia TM, Sabiston CM, Andersen RE, Bengoechea EG. The Motivational Effects of Social Contagion on Exercise Participation in Young Female Adults. . Journal of Sport & Exercise Psychology. 2013;35:563-75. Contact p3620@ismat.pt