Physical activity (PA) significantly influences emotional wellbeing, from enhancing mood to counteracting emotional disorders such as depression and anxiety. This article offers an in-depth analysis of the neurobiological processes and theories underpinning the emotional benefits of PA which arise from exercise-induced physiological changes that simultaneously benefit brain function. We discuss the role of growth factors, neurotransmitters and biochemicals, as well as enhancements in mitochondrial biogenesis and antioxidant activity, and how they foster exercise performance and emotional health. Central to our discussion are theories related to depression: the "neurotrophic," "neurogenesis," "inflammation," "oxidative stress," and "monoamine" hypotheses. We also introduce the emergent "glutamate hypothesis" and discuss exercise-induced lactate release as a potential precursor for glutamate. Additionally, we explore the "endorphin" and "endocannabinoid" hypotheses, underscoring their implications in evoking feelings of euphoria, pain relief and diminished anxiety after exercise. In conclusion, PA exerts a diverse influence on brain health and emotional wellbeing. The dynamic interplay between PA and neurobiological processes signals a promising avenue for future research, with the potential to introduce innovative therapeutic strategies for emotional disorders.
Keywords: endocannabinoid hypothesis; glutamate hypothesis; monoamine hypothesis; neurogenesis hypothesis; neurotrophic hypothesis.