Adaptation to Intermittent Hypoxia/Hyperoxia Enhances Efficiency of Exercise Training

Abstract

This chapter provides an overview of the current concepts on redox signaling pathways, particularly, under hypoxic conditions. The principle of intermittent adaptation effects of variable oxygen levels (short-term hypoxia and hyperoxia) was substantiated and confirmed experimentally in vivo for the first time. The goal of our experiments in rats was to estimate (1) efficiency of physical training conducted separately and in combination with adaptation to intermittent hypoxia/hyperoxia, (2) changes in the rates of free radical processes, and (3) concentration of heat shock proteins (HSP). We found that short-term physical training increased the duration of swimming in acute exhaustive exercise. Combination of physical training with adaptation to hypoxia–normoxia had no effect on this parameter, while adaptation to physical load combined with adaptation to hypoxia–hyperoxia increased the duration of the active swimming phase and, as a consequence, the efficiency of adaptation. Adaptation to physical load and its combination with adaptation to variable oxygen levels increased the resistance of membrane structures to free radical oxidation at the expense of excessive activation of antioxidant defense enzymes in the course of physical training, which was partly compensated for by adaptation to hypoxia/normoxia and was fully prevented by adaptation to hypoxia/hyperoxia. Combination of two forms of adaptation to physical load and to variable oxygen levels markedly compensated/reversed the elevated content of HSP in the course of physical training, which is especially well pronounced during adaptation to hypoxia/hyperoxia. The novel technique is biologically less expensive and more beneficial for the organism.