Effects of Exercise and Rest at a Simulated Altitude on Prevention of Metabolic Syndrome

Growing evidence suggests that high-altitude stay and/or training at a simulated altitude are beneficial for promotion of health and the prevention of metabolic syndrome. For example, staying at high altitude in obese people resulted in weight loss, with reduction of energy intake. In addition, greater reduction of body weight by endurance training at a simulated altitude condition (hypoxic training) was reported, even for relatively short-period of training intervention. Determinations of metabolic and endocrine responses to hypoxic exposure help to elucidate how hypoxic stimulus influences human health. Acute exposure to severe hypoxic condition impaired blood glucose elevation and augmented glucose oxidation in response to a 75 g oral glucose load. Glucose utilization during exercise and post-exercise were significantly elevated in the hypoxic condition than in the normoxic condition. Relatively short-term endurance training in moderate hypoxic condition elicited greater enhancement of glucose tolerance, suggesting improved insulin sensitivity by hypoxic training. Altered appetite regulation during hypoxic exposure, by reducing orexigenic hormones and increasing anorexigenic hormones, might be a key to understand the mechanisms of weight loss following high-altitude stay and/or exercise training under hypoxic condition.