The Acute Effects of a Single Dose of Molecular Hydrogen Supplements on Responses to Ergogenic Adjustments during High-Intensity Intermittent Exercise in Humans
Alharbi AAD, Iwamoto N, Ebine N, Nakae S, Hojo T, Fukuoka Y. · Nutrients. 2022;14(19):3974.
What kind of evidence is this?
Human
Randomized double-blind placebo-controlled crossover study
Exercise and recovery
Other forms
Not reported in this record.
Not reported in this record.
Methods at a glance
Healthy trained male 100-m college athletes.
10 men, mean age 20 years; blood-gas correlation analyses used 7 participants.
Single dose one hour before six 7-second all-out cycling bouts separated by 40-second active intervals.
Four H₂-rich calcium-powder capsules, total 1,500 mg, taken one hour before exercise.
Oral H₂-rich calcium powder — not inhaled gas, not hydrogen water and not Brown's gas.
The single 1,500 mg dose was reported to contain 2.544 µg molecular H₂.
Not applicable — oral capsule powder, not gas inhalation.
No O₂ was co-delivered as an intervention.
Identical H₂-depleted calcium-powder placebo; crossover periods were separated by one to two weeks.
Outcomes and reported result
Resting blood gases and acid-base status, peak power across six bouts, heart rate, local quadriceps oxygenation and recovery.
Only the first bout's peak power favored HCP (839±112 versus 816±108 W, p=0.001); bouts 2–6 were null. Heart rate and overall muscle oxygenation at rest/recovery were null between conditions. HCP increased resting PCO₂/HCO₃⁻ with a tendency toward acidosis and altered selected local oxygenation measures; exploratory correlations used seven participants.
The complete MDPI/PMC article, methods, every exercise bout, blood-gas and muscle-oxygenation results, acknowledgements and conflict disclosure were checked; later null power bouts are explicit.
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
Only 10 men, many endpoints and a performance difference confined to the first of six bouts; some correlations used seven people. One author received an ENAGEGATE research grant and the company provided both powders. This study shares ethics approval 18012 and investigators with the 2021 three-day study, so overlapping participants cannot be excluded.
Healthy trained young male sprinters after one product-specific dose; not evidence for sustained performance or clinical outcomes.
Not reported in this record.
Not reported in this record.
Not reported in this record.
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: 36235628 · DOI: 10.3390/nu14193974
Open-access full article on MDPI and PubMed Central.
MDPI and PMC full article plus PubMed metadata; full-text and article-status check completed 8 August 2026.
2026-08-10