Involvement of Neutrophil Dynamics and Function in Exercise-Induced Muscle Damage and Delayed-Onset Muscle Soreness: Effect of Hydrogen Bath
Kawamura T, Suzuki K, Takahashi M, Tomari M, Hara R, Gando Y, Muraoka I. · Antioxidants. 2018;7(10):127.
What kind of evidence is this?
Human
Placebo-controlled crossover exercise-and-bath trial
Exercise and recovery
Other forms
Not reported in this record.
Not reported in this record.
Methods at a glance
Nine healthy, physically active young men.
9 participants; each completed hydrogen and placebo-bath conditions.
First bath 15 minutes after downhill running; daily 20-minute bathing for seven days in each crossover condition.
After 30 minutes of downhill running at 75–85% of peak oxygen uptake, participants used a 200 L whole-body bath prepared with 2.5 g magnesium hydride, bathing for two 10-minute periods separated by 3 minutes, then repeated daily for seven days.
H₂ generated in bath water from magnesium hydride — topical bath exposure, not inhaled or swallowed and not Brown's gas.
The article specifies the bath agent and volume but does not report a measured dissolved-H₂ concentration for participant baths.
Not applicable — topical bath, not gas inhalation.
No O₂ was co-delivered as part of the intervention.
A visually matched bath using 5.5 g magnesium hydroxide with equivalent magnesium content.
Outcomes and reported result
Muscle soreness, creatine kinase, myoglobin, leukocyte and neutrophil counts, neutrophil migration and reactive-oxygen-species production and inflammatory markers.
The exercise induced soreness and changes in muscle-damage and inflammatory measures, with several correlations involving IL-6 and neutrophils. Hydrogen baths did not improve soreness, muscle-damage markers, neutrophil counts, migration or reactive-oxygen-species production versus placebo.
The complete publisher/PMC article, crossover protocol, bath agents, schedules, correlations, intervention null results, funding and conflicts were checked.
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 trial, many correlated biomarkers and outcomes, incomplete reporting of dissolved-H₂ exposure and home-bath conditions. The H₂ intervention was null. Japanese public research grants supported the work; authors declared no conflict of interest.
Post-exercise bathing in nine active young men; no demonstrated effect on delayed-onset soreness or neutrophil-centered inflammation.
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: 30257503 · DOI: 10.3390/antiox7100127
Open-access publisher article and PubMed Central copy.
MDPI publisher full article, PubMed Central copy and PubMed metadata; full-text extraction checked 8 August 2026.
2026-08-10