Application of Minimum Exercise Model to the Hypoxic Environment

While moderate exercise has been demonstrated to enhance executive function, this beneficial effect may vary depending on the exercise environment. For instance, the decline in blood oxygen levels (hypoxemia) associated with ascent to high altitude has been shown not only to induce acute mountain sickness but also to potentially cause decreased cognitive performance. Therefore, exercise under hypoxic conditions may reduce oxygen delivery to various tissues, thereby attenuating the executive function-enhancing effects of exercise. Previous studies have examined the impact of exercise in hypoxic environments on cognitive function using cognitive task paradigms; however, a consensus has not been reached. One contributing factor to this lack of consensus is the insufficient investigation of how exercise in hypoxic environments affects neural activity in brain regions specific to cognitive function tasks. This limitation stems from the practical difficulties of utilizing positron emission tomography (PET) and magnetic resonance imaging (MRI) systems in hypoxic environments. We addressed these challenges by employing functional near-infrared spectroscopy (fNIRS), which requires only a compact experimental system, is portable, and can be readily installed in gym settings. Our findings revealed that exercise in hypoxic environments induces decreasing cognitive performance, specifically cognitive fatigue, by reducing task-specific neural activity. This chapter provides an overview of our research methodology and results.