<p>This review investigates the intricate relationship between exercise, brain-derived neurotrophic factor (BDNF), neuroplasticity, and cognitive function, with a focus on implications for neuropsychiatric and neurodegenerative disorders. A systematic review was conducted by searching various databases for relevant studies that explored the connections between exercise, BDNF, neuroplasticity, and cognitive health. The analysis of eligible studies revealed that exercise increases BDNF levels in the brain, promoting neuroplasticity and enhancing cognitive functions. Furthermore, we discuss the protective effects of exercise against cognitive decline and neurological disorders, suggesting that BDNF plays a critical role in mediating these effects. Regular physical activity not only elevates BDNF levels but also fosters memory and learning, offering important implications for the prevention and treatment of neuropsychiatric and neurodegenerative conditions. Our findings underscore the necessity of incorporating exercise into a healthy lifestyle to optimize brain health. Future research is essential to elucidate the underlying mechanisms of this relationship and to refine exercise interventions for improved cognitive outcomes.</p>