The brain can benefit from a SINGLE session of exercise.
In this excellent review of the literature published in the journal Brain Plasticity, the authors found consistent evidence that exercise improves executive function and enhanced mood, whilst decreasing levels of stress. Reviewing studies employing electroencephalography (EEG), functional magnetic resonance imaging (fMRI), functional near-infrared spectroscopy (fNIRS), and transcranial magnetic stimulation (TMS), exercise was also found to have widespread effects across brain circuits found in areas such as the hippocampus and hypothalamic-pituitary-adrenal axis. Neurochemical changes were also found in such regions, with well-documented effects on the secretion of cortisol secretion and neurotrophins such as brain-derived neurotrophic factor (BDNF), insulin-like growth factor 1 (IGF-1), and vascular endothelial growth factor (VEGF). Neurotransmitter effects were also considered, focusing on monoamines (dopamine, serotonin, epinephrine and norepinephrine), acetylcholine, glutamate and GABA, together with neuromodulators such as endogenous opioids and endocannabinoids. But perhaps the most important findings are those from human and animal neurochemical studies that appear to reliably and consistently demonstrate that brain changes documented can result from a single session of physical exercise. Read the study.