A REVIEW OF PHYSICAL ACTIVITY’S EFFECT ON MOOD Through the Lens of the HPA Axis

Abstract: Engagement in physical activity (PA) has been said to trigger a chain reaction of events which can alter our mood state. One recently implicated component is the hypothalamic-pituitary-adrenal (HPA) axis, involved in the reaction to physical and psychological stress-ors. This study aims to investigate mood through the lens of the HPA axis when perform-ing PA, specifically aiming to reconfirm this as a paradoxical relationship and if the cross-stressor adaptation hypothesis can then serve as a possible explanation. This study also aims to identify additionally contributing factors to the relationship through examinations of methodological approaches. Furthermore, cognition’s potentially influencing role is spe-cifically examined. A systematic literature review was conducted where data of study de-sign, method, population and results was extracted from each of the studies. Out of the 47 identified studies, a variety of responses in mood and HPA axis activity was found following PA, and the methods employed also varied. Most of the identified studies ex-clusively studied males and participants under the age of 30. Cognitive aspects were found to produce significant differences or to be significantly affected when studies alongside PA, mood and the HPA axis. The varied results and methods did however not allow for a comprehensive analysis and the overrepresentation of younger males did not allow the results to be generalised to the entire population. Further analyses such meta-analyses on a smaller scale is needed.