# Hydrogen-rich water supplementation promotes muscle recovery after two strenuous training sessions performed on the same day in elite fin swimmers: randomized, double-blind, placebo-controlled, crossover trial.
> エリートフィンスイマーにおける同日2回の高強度トレーニング後の筋回復に対する水素水補給の効果：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 trial enrolled 12 elite fin swimmers (8 females, mean age 21.5 years; 4 males, mean age 18.9 years) who completed two same-day high-intensity sessions: 12 × 50 m sprints in the morning and a 400 m competitive swim in the afternoon. Participants consumed hydrogen-rich water (HRW) or placebo for 3 days prior (1,260 mL/day) and 2,520 mL on the experimental day. Assessments of creatine kinase (CK) activity, countermovement jump (CMJ) height, and muscle soreness via visual analogue scale were conducted throughout the day and at 12 and 24 hours post-afternoon session. At the 12-hour mark, HRW was associated with significantly lower CK activity (156 ± 63 vs. 190 ± 64 U/L, p = 0.043), reduced soreness scores (34 ± 12 vs. 42 ± 12 mm, p = 0.045), and greater CMJ height (30.7 ± 5.5 cm vs. 29.8 ± 5.8 cm, p = 0.014) relative to placebo. These findings suggest that a 4-day HRW supplementation protocol may support muscle recovery in elite aquatic athletes undergoing intensive same-day double training.

### Mechanism

Molecular hydrogen's antioxidant and anti-inflammatory properties are thought to attenuate exercise-induced oxidative stress, thereby limiting muscle membrane damage reflected by lower creatine kinase release and facilitating faster restoration of neuromuscular function.

## Bibliographic

- **Authors**: Sládečková B, Botek M, Krejčí J, Valenta M, McKune A, Neuls F, et al.
- **Journal**: Front Physiol
- **Year**: 2024
- **PMID**: [38681143](https://pubmed.ncbi.nlm.nih.gov/38681143/)
- **DOI**: [10.3389/fphys.2024.1321160](https://doi.org/10.3389/fphys.2024.1321160)
- **PMC**: [PMC11046232](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11046232/)
- **Study type**: human randomized controlled trial
- **Delivery route**: hydrogen-rich water
- **Effect reported**: positive

## 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 38681143. https://h2-papers.org/en/papers/38681143
> **Source**: PubMed PMID [38681143](https://pubmed.ncbi.nlm.nih.gov/38681143/)