Effects of pre-exercise H2 inhalation on physical fatigue and related prefrontal cortex activation during and after high-intensity exercise

Yinglu Hong; Gengxin Dong; Qian Li; Vienna Wang; Meng Liu; Guole Jiang; Dapeng Bao; Junhong Zhou

doi:10.3389/fphys.2022.988028

Effects of pre-exercise H₂ inhalation on physical fatigue and related prefrontal cortex activation during and after high-intensity exercise

Front Physiol. 2022 Sep 2:13:988028. doi: 10.3389/fphys.2022.988028. eCollection 2022.

Authors

Yinglu Hong¹, Gengxin Dong¹, Qian Li², Vienna Wang³, Meng Liu², Guole Jiang^{4

2}, Dapeng Bao⁵, Junhong Zhou⁶

Affiliations

¹ School of Sport Medicine and Physical Therapy, Beijing Sport University, Beijing, China.
² Sports Coaching College, Beijing Sport University, Beijing, China.
³ California State University, Long Beach, CA, United States.
⁴ National University of Defense Technology, Changsha, Hunan, China.
⁵ China Institute of Sport and Health Science, Beijing Sport University, Beijing, China.
⁶ Hebrew Senior Life Hinda and Arthur Marcus Institute for Aging Research, Harvard Medical School, Boston, MA, United States.

Abstract

Objective: In this study, we examined the effects of pre-exercise H₂ gas inhalation on physical fatigue (PF) and prefrontal cortex (PFC) activation during and after high-intensity cycling exercise. Methods: Twenty-four young men completed four study visits. On the first two visits, the maximum workload (W_max) of cycling exercise of each participant was determined. On each of the other two visits, participants inhaled 20 min of either H₂ gas or placebo gas after a baseline test of maximal voluntary isometric contraction (MVIC) of thigh. Then participants performed cycling exercise under their maximum workload. Ratings of perceived exertion (RPE), heart rate (HR) and the PFC activation by using functional near-infrared spectroscopy (fNIRS) was measured throughout cycling exercise. The MVIC was measured again after the cycling. Results: It was observed that compared to control, after inhaling H₂ gas, participants had significantly lower RPE at each workload phase (p < 0.032) and lower HR at 50% W_max, 75% W_max, and 100% W_max during cycling exercise (p < 0.037); the PFC activation was also significantly increased at 75 and 100% W_max (p < 0.011). Moreover, the H₂-induced changes in PF were significantly associated with that in PFC activation, that is, those who had higher PFC activation had lower RPE at 75% W_max (p = 0.010) and lower HR at 100% W_max (p = 0.016), respectively. Conclusion: This study demonstrated that pre-exercise inhalation of H₂ gas can alleviate PF, potentially by maintaining high PFC activation during high-intensity exercise in healthy young adults.

Keywords: H2 gas; anti-oxidation; fNIRS; physical fatigue; prefrontal cortex.