<i>Background/Aims:</i> Although studies show a negative relationship between physical activity and the risk for cognitive impairment and late-onset Alzheimer’s disease, studies concerning early-onset Alzheimer’s disease (EOAD) are lacking. This review aims to justify the value of exercise interventions in EOAD by providing theoretical considerations that include neurobiological processes. <i>Methods:</i> A literature search on key words related to early-onset dementia, exercise, imaging, neurobiological mechanisms, and cognitive reserve was performed. <i>Results/Conclusion:</i> Brain regions and neurobiological processes contributing to the positive effects of exercise are affected in EOAD and, thus, provide theoretical support for exercise interventions in EOAD. Finally, we present the design of a randomized controlled trial currently being conducted in early-onset dementia patients.