Author(s): CHEN, W.T., LIN, W.C., HSU, T.C., YOU, W.T., WU, C.L., Institution: NATIONAL CHUNG HSING UNIVERSITY, Country: TAIWAN, Abstract-ID: 446

INTRODUCTION:
Molecular hydrogen has been suggested to have antioxidation and anti-inflammatory properties which may serve as ergogenic aids for sport and exercise performance. Studies have investigated the potential effects of molecular hydrogen, mainly given as hydrogen-rich water, on endurance performance and muscle damage. However, little has been known in terms of the effects of inhaling hydrogen gas on high intensity intermittent exercise (HIIE). Thus, the purpose of current study was to explore the potential effects of acute inhalation of hydrogen gas on high intensity repeated sprint performance.
METHODS:
Fourteen healthy active males (age:22.9±5.4yrs, height:177.8±6.3cm, weight:70.5±8kg) were recruited to participate in this randomized, double-blinded, placebo-controlled, crossover study. Subjects were randomized to inhale either hydrogen gas (H2) (gas generation rate was 1.5L/min, containing 70% hydrogen and 30% oxygen) or normal gas (placebo, ambient air) for 30 mins (including a 10-min warm up), before performing the HIIE test. They were asked to return to the laboratory, after a 7-day washout period, to inhale the other gas in a crossover fashion. The HIIE test, conducting after gas inhalation, comprised 15x6s all-out repeated sprints (20s active recovery between sprints) on a cycle ergometer, and the work load was fixed at 9% of body weight. Blood samples were collected at baseline, pre-test and post-test to analyze blood lactate and arterialized venous blood gas. Rate of perceive exertion (RPE) were recorded at the end of the test. Peak power (PP), mean power (MP), minimum power (MinP), work done (WD), cadence (rpm), fatigue index (FI) and decrement score (Sdec) were recorded during the test. Data were analyzed by using repeated measures ANOVA, and were presented as mean±SD.
RESULTS:
Significant group by time interactions were found in venous blood partial pressure of oxygen (PO2) (p=.012), partial pressure of carbon dioxide (PCO2) (p=.012), total carbon dioxide content (tCO2) (p=.013), base excess (BE) (p=.016), bicarbonate (HCO3) (p=.013) and standard bicarbonate (stHCO3) (p=.022), but not in pH and blood lactate. Furthermore, blood BE (-9±2.8 vs. -10.6±2.9 mmol/L, p<.05) and stHCO3 (17.2±2 vs. 16.1±2 mmol/L, p<.05) concentrations were both found higher at post-test in the H2 trial, which corresponded to the trend of lower variations in BE (p<.05), HCO3 (p<.01) and stHCO3 (p<.05) while performing the HIIE in the H2 trial. As for the sprint performance, no significant differences were observed in PP, MP, MinP, WD, rpm, FI, Sdec and RPE between trials.
CONCLUSION:
The results suggested that pre-exercise acute inhalation of H2 might facilitate a more effective buffering system in blood, which might be explained by the relatively moderate variations in BE and HCO3 during exercise. However, the enhanced magnitude of buffering capacity was not able to alter blood pH and lactate production, which, taken together, resulted in trivial effects on the repeated sprint performance.