Background. A growing body of literature has demonstrated that regular physical activity (PA) and high fitness levels have a positive impact on cognition. Electroencephalogram (EEG) studies, particularly those using event-related brain potentials (ERPs), have played a key role in the growth of the PA-cognition research field. This paper focuses on reviewing the relevant neuroelectric and behavioral findings on the beneficial relationship between PA and cognition across the human lifespan. The discussion focuses on whether PA reflects a general cognitive enhancement or benefits some cognitive processes more than others. Method. An electronic literature search was conducted up to July 2018. Studies were included in this review if they provided behavioral and neuroelectric evidence within healthy people across their lifespan. Results. Previous studies provided strong evidence of PA-linked benefits related to selective attention, cognitive control, and cognitive flexibility. Furthermore, cross-sectional studies proposed a potential improvement in working memory. Overall, reviewed studies suggested that having an active lifestyle could be associated with significant improvements in executive functions. Conclusion. There is much evidence to support the notion that physical activity influences the neural activity of the brain and cognition. A theory to explain why an active lifestyle might benefit some cognitive processes more than others is needed. Furthermore, it is necessary to identify a set of elemental cognitive processes to understand the brain mechanisms underlying each of these processes. Optimizing the amount of PA that could maximize its benefits on brain health and function should be considered in future studies as well.