Hypoxia & Hyperoxia

Abstract

The year 2018 marked the 50th anniversary of the Mexico Olympic games, which represents the starting point of scientific research on hypoxic training. Since the original Live High Train High, many altitude/hypoxic training methods have been developed. The aim of the present review is to present the most recent method called Repeated Sprint training in Hypoxia (RSH). RSH is of unprecedented interest in the altitude training area with 25 studies published in the 5-year period following the pioneer article in 2013, and with only two studies that did not report any beneficial effects.Potential mechanisms include transcriptional factors involved in oxygen-signaling and oxygen-carrying capacity and mitochondrial metabolism enzymes, improved behavior of fasttwitch fibers notably via compensatory vasodilatation, improved vascular relaxation and greater microvascular oxygen delivery as well as faster rate of phosphocreatine resynthesis.In general, RSH leads to superior repeated-sprint ability (i.e., faster mean sprint times or higher power outputs associated witha better resistance to fatigue during a repeated-sprint test) in normoxic conditions. RSH where hypoxia is induced by voluntary hypoventilation at low lung volume (named VHL) may also improve repeated-sprint performance more than in normoxia. Practically, RSH benefits have been demonstrated for a large range of team- (rugby, football, LaCrosse, Australian Football, field hockey), endurance (cycling, track and field, cross-country ski), racket (tennis) or combat (Jiu-Jitsu) sports.KEY WORDS: Altitude, High-Intensity, Team-Sports, Performance, Hypoxia