Investigating the effects of altitude training on blood oxygenation capacity and aerobic training capacity in professional athletes

The background knowledge of this training method is very simple at first. Thinner air at higher altitudes means less air pressure and therefore less oxygen. At an altitude of ۲,۴۰۰ meters, the oxygen in the air is approximately ۷۵% of sea level. At the height of Damavand peak, this amount will be ۵۰%. Oxygen levels are important because they determine the amount of stress on the body. For example, running at an altitude of ۳۰۰۰ meters means spending ۳۰% more energy to run at the same speed at sea level. This extra effort can be hard, but it's what works in the return to lower altitude. An increase in the number of red blood cells in the blood and an increase in capacity for the heart and lungs provide a surplus of benefits that often last for several weeks when returning to normal. This study was designed as a meta-analysis of randomized controlled trials comparing effectiveness of altitude/hypoxic training (experimental) versus sea-level training (control) on oxygen delivery capacity of the blood and aerobic exercise capacity of elite athletes in Korea. Databases (Research Information Service System, Korean studies Information Service System, National Assembly Library) were for randomized controlled trials comparing altitude/hypoxic training versus sea-level training in elite athletes. Studies published in Korea up to December ۲۰۱۵ were eligible for inclusion. Oxygen delivery capacity of the blood was quantified by red blood cell (RBC), hemoglobin (Hb), hematocrit (Hct), erythropoietin (EPO); and aerobic exercise capacity was quantified by maximal oxygen consumption (VO۲max). RBC, Hb, Hct, VO۲max represented heterogeneity and compared post-intervention between altitude/hypoxic training and sea-level training in elite athletes by a random effect model meta-analysis. EPO represented homogeneity and meta-analysis performed by a fixed effect model. Eight independent studies with ۱۵۶ elite athletes (experimental: n = ۸۲, control: n = ۷۴) were included in the metaanalysis. RBC (۴.۴۹۹×۱۰۵ cell/ul, ۹۵ % CI: ۲.۴۶۹ to ۶.۵۲۹), Hb (۵.۴۴۷ g/dl, ۹۵ % CI: ۳.۰۲۸ to ۷.۸۶۶), Hct (۳.۶۳۹ %, ۹۵ % CI: ۱.۶۸۷ to ۵.۵۹۱), EPO (۰.۷۱۱ mU/mL, ۹۵% CI: ۰.۲۸۲ to ۱.۱۴۰), VO۲max (۱.۶۳۷ ml/kg/min, ۹۵% CI: ۰.۵۹۹ to ۱.۴۰۰) showed significantly greater increase following altitude/hypoxic training, as compared with sea-level training.

Keywords:

altitude/hypoxic training , oxygen delivery capacity of the blood , aerobic exercise capacity , meta-analysis , heterogeneity.