Exercise's Impact on Brain and Depression Management

Regular physical exercise has direct and measurable effects on the brain, with significant implications for the prevention and management of depression, stated Alonso Martínez Canabal, a professor at the Department of Cell Biology of the Faculty of Sciences of the National Autonomous University of Mexico. The specialist explained that exercise increases levels of dopamine and serotonin, neurotransmitters involved in mood regulation, which translates into a neurobiologically proven antidepressant effect. In contrast, Martínez Canabal warned that chronic stress significantly reduces neurogenesis, that is, the creation of new neurons, a phenomenon observed even in post-mortem studies. This deterioration affects key brain structures and limits the brain's ability to adapt, reinterpret experiences, and regulate emotions—processes fundamental to mental health. According to the researcher, human memory is dynamic: it preserves information but also reorganizes and re-signifies it without generating conflict with previous learning. Dendrites, covered in neuronal spines, receive information from other neurons and establish the synapses where the small fragments of data that make up memory are stored. To this are added substances released by the muscles, along with insulin-like growth factor, which favor processes of brain plasticity. These mechanisms allow the brain to modify its synaptic connections, generate new dendrites, and extend axons—essential processes for self-repair after events such as strokes or trauma. The specialist emphasized that depression, in its various forms, including chronic and major depression, is characterized by persistent sadness, anhedonia, lack of motivation, and concentration problems, and is closely linked to alterations in memory. In this disorder, he explained, there is an inability to modulate memory realistically and positively, which generates cognitive biases, persistent rumination, and negative self-referential schemas—factors that fuel depressive and anxious states. Chronic stress triggers the sustained release of glucocorticoids, such as cortisol and cortisone, hormones that alert the body to adverse situations. However, their prolonged presence is detrimental to the brain. Studies in animal models have shown that these hormones affect the hippocampus, the prefrontal cortex—related to decision-making—, executive functions, and the reward system, which explains symptoms such as anhedonia. The increase in neurotransmitters and the reduction of stress hormones explain the positive impact of movement on mental health.