Combining exercise and hypoxia for brain health: from elite athlete altitude training camps to clinical applications.

Regular physical exercise promotes overall and brain health and can improve cognition and mood. Similar effects on brain health have been observed after well-controlled intermittent exposures to low ambient oxygen (hypoxia), termed hypoxia conditioning, in several pilot studies. This raises the question of how exercising in hypoxia affects the brain. Among hypoxic exercise training forms are altitude training camps, which have been used systematically by athletes to improve physical performance for many decades, or exposure to simulated altitude/inspiratory hypoxia in laboratory settings, combined or not with exercise. Here, we explore the theoretical basis of overlaps and differences in brain health-related physiological responses to exercise and hypoxia. We present different types of altitude training undertaken by athletes, as well as hypoxia conditioning methods used to enhance physical performance and brain health and to reduce symptoms of neuropsychiatric diseases. We attempt to evaluate the potential of different altitude/hypoxia training types for brain health and indicate potential links to selected clinical applications of combined exercise and hypoxia. In conclusion, the effects of traditional types of altitude training on brain health and function have been poorly investigated, but various benefits of intermittent hypoxia conditioning have been demonstrated, indicating its potential for clinical applications in improving cognition and mental health. Remaining challenges include reducing the stigma surrounding the negative effects of severe hypoxia on the brain, standardizing terminology and approaches to therapeutic hypoxia, and selecting optimized protocols of therapeutic hypoxia exposures and combinations with exercise for specific general health-promoting or clinical applications.