Hydrogen Water Improves Heart Rate Variability at Rest and During Standing Stress
Hydrogen-rich water has a positive effect on heart rate variability at rest and during orthostatic loading, but not during cycling, in healthy adults: A pilot randomized, placebo-controlled crossover trial
Research hubs: Cardiovascular System · Brain & Nervous System
- Authors
- Yuki Muramoto, Emi Minaguchi, Kazuhisa Sugai, Kyohei Daigo, Yuji Iwasawa, Momoi Mizuki, Genki Ichihara, Hiroki Okawara, Tomonori Sawada, Iwao Sakane, Ryo Takemura, Yasunori Satoe, Kazuki Sato, Motoaki Sano, Yoshinori Katsumata
- Journal
- Heliyon
- Year
- 2026
- DOI
- 10.1016/j.heliyon.2026.e44678
- Study Type
- Human
- Outcome
- Positive
- Peer Reviewed
- Yes
- Country
- Japan
- Health Condition
- Autonomic Nervous System Dysfunction
- Body System
- Cardiovascular
TL;DR
Short-term consumption of hydrogen-rich water (HRW) improved measures of autonomic nervous system activity at rest and during postural changes but did not significantly affect physiological responses during exercise.
Key Finding
Hydrogen-rich water improved heart rate variability markers at rest and during a standing stress test, but had no measurable effect on physiological responses during moderate-to-high intensity cycling.
Summary
This study tested whether drinking hydrogen-rich water affects the body's automatic nervous system (the system that controls heart rate, breathing, and other functions without conscious effort) in 47 healthy adults. Participants drank hydrogen-rich water or plain water before two tests: one measuring heart rate variability (small natural changes in the time between heartbeats, which reflect nervous system health) at rest and during a standing stress test, and one involving 30 minutes of cycling. Hydrogen-rich water improved heart rate variability at rest and while standing up, but it did not change heart rate, blood lactate, or oxygen use during cycling exercise.
Practical Takeaway
This small pilot trial suggests that drinking hydrogen-rich water may support autonomic nervous system function — particularly the body's ability to regulate heart rate at rest and when changing posture — but early evidence indicates it does not enhance performance or reduce fatigue during exercise. Because this was a pilot study with 47 participants and a short intervention period, larger and longer trials are needed before drawing firm conclusions.
Abstract (excerpt)
Hydrogen-rich water has various health benefits, such as substantially reducing lactate accumulation during high-intensity exercise. However, little is known about the effects of hydrogen-rich water on physiological responses during physical activity compared to those at rest. Therefore, we…