In this paper, a brief overview of some interesting mediators of the impact of physical activity on the central nervous system is provided. The body's response to physical activity itself is a complex event involving the release of hormones and metabolites that regulate energy metabolism and water metabolism. Some of these factors also influence brain functions. Βendorphin acts as an analgesic, causing the so-called "runner's high" feeling in long-distance runners. Physical activity modulates the activity of the serotonergic and dopaminergic systems, whose dysfunction plays a role in the mechanisms of depression and addiction. Exercise is also associated with the secretion of BDNF (brain-derived neurotrophic factor), which has roles in inducing synaptic plasticity processes, the neuronal properties underlying various cognitive functions. Short-term physical activity can stimulate the release of orexin in the brain, thus activating wakefulness and attention, among other things. Lactate, which was previously considered only a byproduct of anaerobic metabolism, has been shown to serve as an energy source for neurons and a modulator of various brain functions, with additional potential roles in the prevention of age-related cognitive disorders. All of this suggests that the brain is not only an organ for thinking but also an organ for movement.