Experimental manipulation in everyday life: Application of an intra-individual design for the causal testing of sedentary breaks on affective and cognitive parameters.

• Applicant: Dr. Marco Giurgiu
• Subject Area: Personality Psychology, Clinical and Medical Psychology, Methodology
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 496846758

Sedentary breaks are associated with positive health outcomes (including cardiovascular and metabolic parameters). The within-subject associations, especially with cognitive and affect-related parameters, will be considered based on theoretical considerations for a better understanding of temporary antecedents and consequences of sedentary breaks. First empirical results in everyday life suggest associations but simultaneously bring the methodologically challenging question of causality into focus. Accordingly, the research project investigates a possible causal effect of sedentary breaks on affective and cognitive parameters in everyday life. It is hypothesized that breaking up sedentary behavior, compared to uninterrupted sedentary bouts, positively affects affective and cognitive parameters (i.e., mood and working memory). In addition, we will examine to what extent break intensity moderates the potential causal effect. In 200 university employees, physical activity, sedentary behavior, and sleep will be continuously measured via "wearables". Furthermore, mood and working memory will be captured up to six times a day on an electronic diary via a smartphone application. An algorithm detects in real-time at least six sedentary bouts per day of at least 30 minutes. During three of these phases, participants are encouraged to break up sedentary behavior while varying break intensity (standing break, walking at a relaxed pace, and walking briskly). The other three sedentary bouts served as control conditions, where no encouragement to change behavior will be provided. The within-person encouragement approach thereby enables to tackle the question of causality under ecological conditions. Prior to the everyday life study, executive functions (inhibition control, working memory, and cognitive flexibility) will be tested on a computer, and a spiroergometric endurance performance test on a treadmill will be performed under laboratory conditions. The study purpose is i) to provide methodological insights about causality under ecological conditions and ii) to provide more precise recommendations for sedentary breaks.

• DFG Programme: Research Grants