# Hydrogen-Rich Water as a Performance-Enhancing Aid in National-Level Finswimmers: A Randomized, Double-Blind, Placebo-Controlled Crossover Study.
> フィンスイミング競技者における水素水摂取がパフォーマンスおよび生理的指標に与える影響：無作為化二重盲検プラセボ対照クロスオーバー試験


## Abstract

This randomized, double-blind, placebo-controlled crossover study enrolled 12 national-level finswimmers (8 females, 4 males; mean ages 21 and 19 years) to examine the effects of 4-day hydrogen-rich water (HRW) supplementation at 0.9 ppm hydrogen concentration. Participants completed morning sessions of 3 sets of 4 × 50-m surface sprints and an afternoon 400-m surface time trial. Daily HRW intake was 1260 mL for the first 3 days and 1680 mL on the day preceding the time trial, with a 1-week washout between conditions. Blood lactate, rating of perceived exertion, and plasma protein carbonyls were assessed as secondary endpoints. The 400-m time trial showed a statistically significant 0.6% improvement with HRW versus placebo (P = .003), whereas 50-m sprint times improved by only 0.5% without reaching significance (P = .12). No significant between-condition differences were detected for blood lactate, perceived exertion, or protein carbonyl levels. These findings indicate that short-term HRW intake may confer a small but meaningful benefit specifically for middle-distance swimming performance, while effects on repeated sprint capacity and measured physiological markers appear negligible.

### Mechanism

HRW was hypothesized to reduce oxidative stress, as reflected by plasma protein carbonyls, potentially preserving muscle function during sustained effort; however, no significant changes in oxidative stress markers were observed, leaving the mechanism of the 400-m performance benefit unclear.

## Bibliographic

- **Authors**: Sládečková B, Krejčí J, McKune A, Pyne DB, Bajgar R, Botek M
- **Journal**: Int J Sports Physiol Perform
- **Year**: 2026 (2026-04-16)
- **PMID**: [41991147](https://pubmed.ncbi.nlm.nih.gov/41991147/)
- **DOI**: [10.1123/ijspp.2025-0492](https://doi.org/10.1123/ijspp.2025-0492)
- **Study type**: human randomized controlled trial
- **Delivery route**: hydrogen-rich water
- **Effect reported**: mixed

## Delivery context

Hydrogen-rich water is a low-risk delivery route, but the achievable systemic hydrogen dose is bounded. For clinical applications, inhalation is the most efficient route; inhalation, however, carries explosion risk, and concentration matters (empirical LFL of 10% applies to inhalation environments; high-concentration devices are documented in the Consumer Affairs Agency accident database and are not recommended).

## Safety notes

Hydrogen-rich water is a low-risk delivery route, but the achievable systemic hydrogen dose is bounded. For clinical applications, inhalation is the most efficient route; inhalation, however, carries explosion risk, and concentration matters (empirical LFL of 10% applies to inhalation environments; high-concentration devices are documented in the Consumer Affairs Agency accident database and are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)
- [Inhalation safety threshold lineage](https://h2-papers.org/en/safety-notes/lineage)

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> **Cite as**: H2 Papers — PMID 41991147. https://h2-papers.org/en/papers/41991147
> **Source**: PubMed PMID [41991147](https://pubmed.ncbi.nlm.nih.gov/41991147/)