Abstract: Objective:To clarify the important theoretical and practical significance of physical activities/exercise and brain-related research in the global "brain plan" context and aim at academic frontiers. Methods:Based on the opportunity of the 64th Annual Meeting of American College of Sports Medicine and the First International Conference on Basic Science of Exercise and the Brain, this paper makes a systematic review of 40 years of research on the relationship between physical activities/exercise and brain. Results: An increasing number of studies have consistently demonstrated that cardiorespiratory fitness or aerobic capacity as well as physical activities that help improve the capacity have positive effects on the cognitive health of the brain, which, in addition to modifying the structure and function of brain, increase the levels of brain-derived neurotrophic factor (BDNF), insulin-like growth factor 1, (IGF-1), and vascular endothelial growth factor (VGEF) through a highly-accepted mechanism based on animal models, and enhance nutrient transport and waste clearance by increasing cardiorespiratory fitness. Among them, the current research on children population is relatively systematic and comprehensive, and is followed by that on the elderly population. Conclusion:Although there are many reproducible results about the brain function and structure, including the explanation for the molecular level, the establishment of the specific association mode between exercise, brain and cognition still faces harsh challenges and needs continuous improvement and research . This article also gives some suggestions for future research.

Key words: physical activities/ exercise, brain, cardiorespiratory fitness, aerobic exercise, cognitive health