Background: Hydrogen gas (H2) has entered the world of experimental therapeutics approximately
four and a half decades ago. Over the years, this simple molecule appears to drive more scientific attention, perhaps
due to a dualism of H2 affirmative features demonstrated in numerous in vitro, animal and human studies
on one side, and still puzzling mechanism(s) of its biological activity on the other. Up to this point, H2 was scrutinized
for more than 170 different disease models and pathologies, and many research groups across the world
have lately started to dynamically investigate its conceivable performance-enhancing potential.
Methods: We outlined here the studies indexed in leading research databases (PubMed, Web of Science, SCOPUS,
JSTORE) that explored the effects of hydrogen on exercise performance, and also addressed important restraints,
open questions, and windows of opportunities for forthcoming research and possible H2 enactment in
exercise physiology. About two dozen trials have been identified in this domain, with most of the trials published
during the past 5 years, while drinking hydrogen-rich water recognized as the most convenient method to
deliver H2 in both animal and human studies.
Results: Either administered as an inhalational gas, enteral hydrogen-rich water, or intravenous hydrogen-rich
saline, H2 seems to favorably affect various exercise performance outcomes and biomarkers of exercise-associated
fatigue, inflammation, and oxidative stress. Not all studies have shown corroborative effects, and it appears
that the gold-standard protocol for applying H2 in the field of exercise science does not exist at the moment,
with studies markedly differ in the dose of H2 administered, the duration of treatment, and the source of
Conclusion: H2 is a newfangled and rather effective performance-enhancing agent, yet its promising ergogenic
potency has to be further validated and characterized in more well-controlled, appropriately sampled and longterm
mechanistic trials. Also, appropriate regulation of hydrogen utilization in sport as an exotic medical gas
may require distinctive legislative actions of relevant regulatory agencies in the future.