| The Effects of Hypoxic and Hyperoxic Environments on Metabolic Adaptations to Endurance Training in Rats |
| Paper ID : 1047-SPORTCONGRESS (R1) |
| Authors |
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hossein barzegar piralgher * Department of Exercise physiolog , Faculty of Educational Sciences and Psychology, University of Mohaghegh Ardabili , Ardabil , iran |
| Abstract |
| Introduction Oxygen is a critical regulator of cellular metabolism and energy homeostasis. Both hypoxic and hyperoxic conditions can induce specific metabolic and molecular adaptations that influence exercise performance. This study aimed to investigate the effects of endurance training under different oxygen levels on metabolic pathways and performance outcomes in rats. Methods Forty adult male Wistar rats were randomly assigned to three groups: control (normoxia, 21% O₂), hypoxia (15% O₂), and hyperoxia (60% O₂). Animals underwent a 6-week treadmill endurance training program at 65–85% of VO₂max. After the intervention, blood, liver, and skeletal muscle samples were collected to evaluate biochemical markers, enzymatic activity, and gene expression related to energy metabolism. Results Exposure to hypoxia caused a metabolic shift toward anaerobic glycolysis, as indicated by a 42% increase in blood lactate concentration and a 1.8-fold elevation in lactate dehydrogenase (LDH) activity. In contrast, hyperoxia enhanced mitochondrial oxidative capacity by 27% and upregulated PGC-1α expression by 3.2-fold, suggesting improved mitochondrial biogenesis. Mechanistically, HIF-1α activation in hypoxia increased PDK4 expression and inhibited the pyruvate dehydrogenase complex, while hyperoxia induced mild oxidative stress that triggered adaptive mitochondrial and antioxidant responses. These adaptations resulted in an 18% improvement in time to fatigue in the hyperoxia group. Conclusion Training under hyperoxic conditions may serve as an effective complementary strategy to enhance endurance performance or assist in the rehabilitation of patients with respiratory limitations. However, hypoxic protocols should be applied with caution due to excessive lactate accumulation and a 35% reduction in hepatic glycogen reserves. Future studies incorporating epigenetic and microbiome analyses are recommended to provide deeper insight into oxygen-dependent metabolic regulation. |
| Keywords |
| Oxygen availability; Hypoxia; Hyperoxia; Endurance training; Energy metabolism; Mitochondrial adaptation |
| Status: Abstract Accepted (Poster Presentation) |
