Inhalation of molecular hydrogen increases breath acetone excretion during submaximal exercise: a randomized, single-blinded, placebo-controlled study.

Abstract

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.

Mechanism

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.