Pilot study: Effects of drinking hydrogen-rich water on muscle fatigue caused by acute exercise in elite athletes
Aoki K et al. · Med Gas Res. 2012;2:12.
What kind of evidence is this?
Human
Double-blind crossover pilot study
Exercise and recovery
H₂-rich water
Not reported in this record.
Not reported in this record.
Methods at a glance
Male soccer players in daily training
10 participants
Each participant completed both conditions at one-week intervals; acute exercise observation
Three 500 mL bottles: one at 22:00 before testing and two at 05:00 and 06:20 on the test day; 1,500 mL total
H₂ dissolved in water — H₂ only, not Brown’s gas.
0.92–1.02 mM dissolved H₂, generated by magnesium sticks after 24 hours.
Not applicable — oral water, not gas inhalation.
No O₂ was co-delivered as part of the intervention.
Mineral water prepared with visually matched placebo sticks; measured H₂ concentration 0
Outcomes and reported result
Blood lactate, oxidative-stress markers, creatine kinase, peak torque and muscle activity
The paper reports lower post-exercise blood lactate with H₂ water than placebo and no early decline in peak torque; oxidative markers, creatine kinase and EMG frequency measures did not differ between conditions.
Methods, principal results, funding and competing-interest statements checked in the free full text; independent appraisal remains incomplete.
A reported association, difference or mechanism is not automatically a clinical benefit. Null findings, outcome type, study design and precision all matter.
Cautions and applicability
Very small pilot sample, acute protocol and multiple outcomes; no female, untrained or recreational participants. Product-specific magnesium sticks were used; authors declared no competing interests and reported a Daimaru Research Foundation grant.
Young trained male soccer players completing the study exercise protocol.
Cochrane RoB 2 crossover variant · post-exercise lactate and peak-torque results
Some concerns — preliminary; independent reviewer pending
Very small crossover pilot. Double blinding and placebo sticks are described, but allocation sequence, concealment, period effects and multiplicity need fuller assessment.
Some concerns — crossover order and concealment are not sufficiently described in the extracted methods. · Some concerns — placebo sticks and double blinding are reported; adherence beyond preparation instructions is limited. · Low concern in the displayed report — all 10 participants appear in the analyzed crossover data. · Low to some concerns — largely objective laboratory and performance measures, though operator blinding is not fully described. · Some concerns — numerous biochemical and performance outcomes without a registered analysis plan identified.
No single-study GRADE certainty rating is assigned. Certainty is assessed by important outcome across a complete eligible evidence set, not by attaching a final grade to one source.
Sources and record status
PMID: 22520831 · DOI: 10.1186/2045-9912-2-12
Open-access article.
Free full text on PMC; bibliographic identifiers cross-checked in PubMed.
2026-08-10