A growing body of evidence suggests that physical activity is effective for improving brain health throughout the lifespan. Despite the emerging recognition of physical activity as a powerful method to enhance brain health, there is continued confusion from both the public and scientific communities about what the research has discovered about the potential for physical activity to improve brain health and which questions remain unanswered. From this perspective, I will discuss the current research on exercise and brain health and will focus on its impact throughout the lifespan. I will conclude that physical activity decreases the risk for brain diseases and disorders, ameliorates symptoms, improves function, and increases brain volume and that we are beginning to have a better understanding of the factors that moderate and mediate these associations. Overall, physical activity is an important modifiable lifestyle that carries significant consequences for learning, memory, and brain health for people of all ages.