Hydrogen-rich water supplementation promotes muscle recovery after two strenuous training sessions performed on the same day in elite fin swimmers
Sládečková B et al. · Front Physiol. 2024;15:1321160.
What kind of evidence is this?
Human
Randomized double-blind placebo-controlled crossover trial
Exercise and recovery
H₂-rich water
Not reported in this record.
Not reported in this record.
Methods at a glance
Elite fin swimmers: 8 women and 4 men
12 participants
Four-day supplementation around two same-day training sessions; 24-hour recovery follow-up; 1-week crossover washout
1,260 mL/day hydrogen-rich water for 3 days before testing and 2,520 mL on the experimental day
H₂ dissolved in water — H₂ only, not Brown’s gas.
0.9 ppm dissolved H₂; the full protocol reports 2.8 mmol H₂ across 6,300 mL during each intervention period.
Not applicable — oral water, not gas inhalation.
No O₂ was co-delivered as part of the intervention.
Matched H₂-free placebo water; 0.0 ppm dissolved H₂
Outcomes and reported result
Countermovement jump, creatine kinase and perceived muscle soreness through 24 hours of recovery
At 12 hours after the afternoon session, H₂ water was associated with lower creatine kinase (156 ± 63 vs 190 ± 64 U/L; p=0.043), lower soreness (34 ± 12 vs 42 ± 12 mm; p=0.045) and a 0.9 cm higher countermovement jump (p=0.014).
Methods, outcome values, trial registration, funding and conflict statements checked in the open-access 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 crossover study with multiple outcomes and time points. One author reported work as an external consultant to H2 Global Group; university funding was reported.
Elite fin swimmers completing two strenuous training sessions on the same day.
Cochrane RoB 2 crossover variant · 12-hour recovery outcomes
Some concerns — preliminary; independent reviewer pending
Prospective registration, computer-generated sequence and matched placebo are reported, but the sample is very small and multiple recovery outcomes and time points were tested.
Low to some concerns — computer-generated order is reported; concealment details remain limited. · Low concern in the displayed report — matched water, double blinding and a crossover washout are described. · Low concern in the displayed report — all 12 athletes appear in the analyses. · Low to some concerns — jump height and creatine kinase are objective; soreness is subjective. · Some concerns — multiple outcomes and time points; registry-to-report comparison is not yet complete.
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: 38681143 · DOI: 10.3389/fphys.2024.1321160
Open-access publisher and PMC full texts are available.
Open-access full text through Europe PMC/PMC, PubMed record and ClinicalTrials.gov registration.
2026-08-10