Traumatic brain injury (TBI) is defined as functional alterations or other pathological changes in the brain caused by external forces, which is a significant public health issue worldwide. Currently, a large number of studies have proved that exercise, as a nonpharmacological treatment, can effectively improve TBI. Exercise both before and after injury can benefit TBI recovery through specific mechanisms. This article summarizes the effects of exercise before and after injury on TBI and their potential regulatory mechanisms, aiming to provide an in-depth understanding of the mechanisms through which exercise improves TBI, thereby offering a theoretical basis for the clinical application of exercise in the prevention and treatment of TBI.