最大下運動中の水素ガス吸入が呼気アセトン排出量に与える影響：無作為化単盲検プラセボ対照試験
This randomized, single-blinded, placebo-controlled crossover study examined whether inhaling 1% molecular hydrogen (H2) during aerobic exercise influences lipid metabolism, assessed non-invasively via breath acetone concentration. Ten male participants performed 20 minutes of cycling at 60% peak oxygen uptake while breathing either 1% H2 or a control gas. H2 inhalation significantly elevated both breath acetone output and oxygen uptake during exercise (P < 0.01). In a separate resting condition involving six male subjects seated for 45 minutes, no significant changes in breath acetone or oxygen uptake were detected. Markers of oxidative stress and antioxidant activity were likewise unaffected. The findings indicate that H2 inhalation during exercise may enhance hepatic lipid metabolism in an exercise-dependent manner, potentially linked to augmented mitochondrial oxidative phosphorylation.
H2 inhalation is proposed to enhance mitochondrial oxidative phosphorylation, thereby accelerating hepatic lipid metabolism during exercise and increasing ketone body (acetone) production detectable in exhaled breath.
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/33004705