Physical Activity in Children and Adults – Associations with Affect and Impact on Executive Functions

Abstract

Physical inactivity is a wide-spread phenomenon in the Western world. It has detrimental influences on health, resulting in the fourth-leading risk factor of global mortality. In addition to being an effective tool for improving physical health, physical activity can also serve to improve mental health. The present dissertation aims at investigating the potential benefits of physical activity for affect and executive functions, both representing aspects of mental health. To be more precise, the research aim of the present dissertation is trifold. First, the associations between physical activity and affect in young adults’ daily lives are investigated by applying ambulatory assessment (Manuscript 1). Second, the application of ambulatory assessment in the school context, including the assessment of physical activity, affect and executive functions, and its advantages for supporting educational success are reviewed (Manuscript 2). Third, the effectiveness of a physical activity intervention for improving executive functions in young children is investigated in a standardized intervention study (Manuscript 3). Thereby, the present dissertation extends and enriches theoretical and empirical knowledge in two ways. On the one hand, it focuses in particular on the transfer of effects into everyday life by relying on ambulatory assessment. On the other hand, it targets specific age groups, young adults and young children, that seem to be highly susceptible for the benefits of physical activity since young adults’ affect is especially low and young children’s executive functions are still developing. Manuscript 1 investigated the associations between physical activity and affect in young adults’ daily lives. Ambulatory assessment was applied in an intensive longitudinal study, conducted in 189 young adults across 10 consecutive days. Participants wore accelerometers to objectively assess moderate-to-vigorous physical activity continuously throughout the day and reported their affect in time-stamped online diaries before going to sleep. Multilevel analyses revealed significant within-person associations between daytime physical activity and same-day’s evening affect. On days when participants engaged in more activity than usual, they reported not only less depressed and less angry affect in the evening, but also more vigor and serenity. These results extend previous findings with evidence obtained in real life and by focusing on the associations between physical activity and specific affect states. Further on, the results of this manuscript allow deriving practical implications for health promotion programs for young adults. Manuscript 2 provided a literature review on the application of ambulatory assessment in the school context. It introduced ambulatory assessment as a method that enables investigating fluctuations in physiological and mental processes within students and teachers. Specifically, applying ambulatory assessment methods can detect intraindividual changes and fluctuations in behavioral (e.g., physical activity), affective, and cognitive (e.g. executive functions) processes as they naturally occur within a school day or across days. Thereby, a high ecological validity can be reached and contextual factors of various modalities are assessable. Moreover, the results of ambulatory assessment studies in school can lay the foundation for developing theories on the etiology of academic achievement. Consequently, this manuscript highlights the benefits of applying ambulatory assessment in school to support educational success. Manuscript 3 described a standardized intervention study in 103 young children that tests the effectiveness of acute physical activity for improving executive functions and also takes the moderating influence of previous motor coordination experiences into account. Children were randomly assigned to a physical activity or sitting control condition, both conducted in a one-on-one experimenter-child setting. Executive functions were assessed with two tasks directly following the interventions. Motor coordination experiences were measured with a parental questionnaire. Regression analyses revealed no difference in both executive function tasks between children in the physical activity compared to the control condition. However, individual differences in children’s motor coordination experiences moderated the effectiveness of physical activity for executive functions. Children with lower levels of motor coordination experiences showed negative effects of physical activity on executive functions compared to a sitting activity, whereas children with higher levels of motor coordination experiences showed a trend indicating positive effects of physical activity on executive functions. These results allow drawing causal inferences about the effects of physical activity on executive functions and extend prior findings by its application of standardized methods in young children. Furthermore, practical implications for the use of physical activity in early education can be derived. As a whole, the present dissertation shows that physical activity can serve as a tool for enhancing affect in young adults and executive functions in young children, and thus, for improving mental health. In addition, it underlines the value of applying ambulatory assessment to obtain evidence in real life and in particular in the school context to support education. Consequently, the present dissertation contributes conceptual knowledge about the potential of physical activity for improving affect and executive functions. Practical implications for how physical activity can be used to support health and education are discussed together with directions for future research.