Hydrogen Water Baths Keep Your Body Warmer Longer Than Regular Baths
Heat-retention effects of hydrogen-rich water bath assessed by thermography for humans
Research hubs: Cardiovascular System
- Evidence type
- Controlled trial (non-randomized) · Human study
- Authors
- Shinya Kato, Yuki Takada, Nobuhiko Miwa
- Journal
- Journal of Thermal Biology
- Year
- 2021
- PMID
- 33454037
- Study Type
- Human
- Participants
- 24
- Delivery
- Water (Electrolysis)
- Dose
- 41 °C, 10-min bathing
- H₂ concentration
- 185-548 μg/L
- Duration
- 1 day or less
- Outcome
- Positive
- Peer Reviewed
- Yes
- Cited by
- 3 (OpenAlex, as of November 2026)
- Country
- Japan
TL;DR
Taking a bath in hydrogen-rich water seems to keep certain parts of the body warmer for longer and may improve blood flow better than a regular bath.
Key Finding
Hydrogen-rich water baths produced greater heat retention in the abdomen, upper legs, arms, and hands for up to 60 minutes after bathing compared to regular water baths, with evidence suggesting improved blood circulation as a potential mechanism.
Summary
Researchers used thermal imaging cameras to measure how well heat stays in the body after bathing in hydrogen-rich water versus regular water. In 24 healthy people, hydrogen-rich water baths (at 41°C for 10 minutes) kept the abdomen, upper legs, arms, and hands warmer for 30-60 minutes after bathing compared to regular water baths. The study also found that blood vessels in fingertips expanded more after hydrogen-rich water bathing, suggesting the effect may involve improved blood circulation rather than just better insulation.
Practical Takeaway
This small study suggests hydrogen-rich water bathing may help retain body heat longer than regular bathing, possibly through effects on blood flow. However, the study involved only 24 people and measured thermal effects immediately after bathing—longer-term health benefits remain unclear. More research is needed to determine whether these heat-retention effects translate to meaningful health outcomes.
Abstract (excerpt)
Hydrogen-rich water bath devices are commercially available, but have been scarcely clarified for heat-retention effects. In this study, heat-retention effects of hydrogen-rich water bath were assessed by thermographic clinical trials, which employed twenty-four healthy subjects. The thermograms…