Hydrogen-Rich Water as a Performance-Enhancing Aid in National-Level Finswimmers: A Randomized, Double-Blind, Placebo-Controlled Crossover Study
Sládečková B et al. · Int J Sports Physiol Perform. 2026;21(7):824–830.
What kind of evidence is this?
Human
Randomized double-blind placebo-controlled crossover study
Exercise and recovery
H₂-rich water
Not reported in this record.
Not reported in this record.
Methods at a glance
National-level finswimmers: 8 women and 4 men
12 participants — the same registered cohort as PMID 38681143, reported here for different outcomes
Four-day supplementation and two same-day swimming sessions; 1-week crossover washout
1,260 mL/day hydrogen-rich water for 3 days before testing and 1,680 mL on the experimental day before the 400 m time trial
H₂ dissolved in water — H₂ only, not Brown’s gas.
0.9 ppm dissolved H₂.
Not applicable — oral water, not gas inhalation.
No O₂ was co-delivered as part of the intervention.
Matched placebo water
Outcomes and reported result
Three sets of four 50 m sprints, 400 m time trial, blood lactate, perceived exertion and plasma protein carbonyls
Morning 50 m sprint times did not significantly improve (0.5%; p=0.12). The afternoon 400 m time trial improved by 0.6% (p=0.003). Lactate, perceived exertion and protein carbonyls did not differ (all p≥0.12).
Abstract, registry and author-uploaded full text checked; 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 crossover cohort. This record and PMID 38681143 must not be counted as two independent participant groups. The statistically significant 400 m difference was small, while sprint, lactate, perceived-exertion and oxidative-stress outcomes were null.
National-level finswimmers under the reported short supplementation and competition-simulation protocol.
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: 41991147 · DOI: 10.1123/ijspp.2025-0492
Publisher full text requires payment or institutional access.
Author-uploaded ResearchGate full text, PubMed record and ClinicalTrials.gov registration.
2026-08-10