A119: Intermittent Hypoxic Training Promotes Whole-Body HIF-1ΑExpression to Improve Exercise Capacity

Research Context: It has been shown that a hypoxic environment induces up-regulation of HIF-1α and changes in its downstream gene sequences, and that exercising under hypoxic conditions improves athletes' sprint performance. However, there is more controversy regarding the effects of exercise under hypoxic conditions on exercise capacity, and the molecular mechanisms have been less well studied. Therefore, the aim of this study was to investigate the link between HIF-1α expression and exercise capacity under hypoxic conditions of exercise, and to provide a realistic theoretical basis for intermittent hypoxic training to improve exercise capacity. Research Methodology: A total of 480 wild-type female Drosophila flies that were fledged within 12 hours were collected and randomly divided into control (NC), hypoxic quiet (HC), normoxic exercise (NE), and intermittent hypoxic training (HE) groups, with 120 flies in each group. At 7 days of age, intermittent hypoxic, normoxic and hypoxic combined exercise interventions were performed for 5 consecutive days, lasting 1 hour per day, respectively. Gases used in both the HC and HE groups were a mixture of 6% O2 and 94% N2. RT-qPCR was used to detect the expression of HIF-1α throughout the body, and the average speed, acceleration, and distance moved per unit time of Drosophila were quantified using LoliTrack Animal Behavioral Analysis Software, as well as the jumping ability and climbing ability of Drosophila. Findings: Intermittent hypoxic exposure, normoxic exercise, and intermittent hypoxic training all significantly upregulated HIF-1α expression compared with the NC group (P < 0.001). In terms of jumping ability, both intermittent hypoxic training and normoxic exercise improved the climbing ability of Drosophila compared to the NC group (P < 0.001), whereas intermittent hypoxic exposure alone did not play a role. In terms of climbing ability, Drosophila's jumping ability was significantly improved after intermittent hypoxic training compared to the NC group (P < 0.001); however, no significant changes could be observed in experiments with normoxic exercise as well as intermittent hypoxic exposure. In terms of behavioral analysis, the mean speed of Drosophila movement was increased in the HE group compared to the NC group (P < 0.001), acceleration increased (P < 0.001), distance traveled increased (P < 0.001), and normoxic exercise increased the distance traveled by Drosophila (P < 0.05). Conclusion: Intermittent hypoxic training promotes HIF-1Α expression and improves locomotor performance in Drosophila.