Regular physical activity induces a range of adjustment changes, particularly in the circulatory system and metabolism. Numerous publications on single exertion and increased physical activity more and more frequently confirm their positive influence on the shaping of cognitive functions. Anatomic and functional changes, such as increased cerebral blood flow, angiogenesis and neurogenesis as well as increased volume of the grey matter in the frontal and temporal cortices, are the basis of this positive influence. Physical exertion stimulates the production of trophic factors, among which the brain-derived neurotrophic factors and insulin-like growth factors are crucial for cognitive processes, synaptic plasticity as well as for the improvement of the neurogenesis signalling pathways and vascular functioning. Physical activity induces enhanced expansion of the brain-derived neurotrophic factor. This has a positive influence on energy processes and activates numerous cerebral energy centres which positively modify the synaptic potential for processing information that is important for developing cognitive functions. Exertion reduces inflammation by decreasing the blood concentration of proinflammatory cytokines that can contribute to the development of neurodegenerative processes. Moreover, it reduces metabolic syndrome risk factors, particularly hypertension and insulin resistance thus decreasing the risk of cognitive dysfunctions, improving brain functioning, delaying the onset and decelerating the development of disorders in neurodegenerative syndromes, including Alzheimer’s and Parkinson’s diseases. Taking these mechanisms into consideration, it seems that physical activity is indispensable for maintaining normal cognitive functions at any age.