運動後回復期における水素リッチガス混合物の鼻カニューレ吸入が酸化ストレス・筋損傷・運動パフォーマンスに与える影響
This double-blind, crossover study enrolled eight physically active males who inhaled either a hydrogen-rich gas mixture (HG; inspired H2 fraction up to 4.08%) or placebo air for 60 minutes following an oxidative stress-inducing exercise protocol consisting of treadmill running at 75% VO2max and squat jumps (5 sets × 10 repetitions). Blood and urine samples were collected before exercise and 10 minutes after gas inhalation, alongside assessments of jumping ability, pedaling power, and muscle strength. HG inhalation significantly suppressed the post-exercise rise in urinary 8-hydroxydeoxyguanosine excretion rate (a DNA oxidation marker; P < 0.05) and attenuated the decline in countermovement jump height (P < 0.05) relative to placebo. Other performance and blood-based oxidative or muscle damage markers showed no significant between-condition differences. A strong negative correlation was observed between the increase in urinary 8-hydroxydeoxyguanosine and the reduction in jump performance (r = −0.78, P < 0.01), suggesting that systemic DNA oxidative damage may contribute to post-exercise performance decrements.
Inhalation of H2-rich gas is proposed to scavenge reactive oxygen species responsible for DNA oxidation, thereby reducing urinary 8-hydroxydeoxyguanosine accumulation and preserving neuromuscular performance during post-exercise recovery.
For inhalation applications of molecular hydrogen, the lower flammability limit (LFL) deserves careful handling. The classical 4% figure applies to closed-system mixtures; the practical inhalation-environment threshold is 10%. Even pure-hydrogen output (the UFL 75% paradox) passes through the flammable range at the air–gas boundary. High-concentration (66% / 100%) inhalers are documented in the Japanese Consumer Affairs Agency accident-information database and are not recommended.
See also:
https://h2-papers.org/en/papers/33380581