Hydrogen Gas Boosts Fat Burning During Exercise, Study Finds
Inhalation of molecular hydrogen increases breath acetone excretion during submaximal exercise: a randomized, single-blinded, placebo-controlled study
Research hubs: Respiratory System
- Evidence type
- Randomized controlled trial · Human study
- Authors
- Amane Hori, Masatoshi Ichihara, Hayata Kimura, Hisayoshi Ogata, Takaharu Kondo, Norio Hotta
- Journal
- Medical Gas Research
- Year
- 2020
- PMID
- 33004705
- Study Type
- Human
- Participants
- 10
- Delivery
- Gas
- Dose
- 1% H2 inhalation during 20-minute submaximal exercise at 60% peak oxygen uptake
- H₂ concentration
- 1% H2 gas
- Duration
- 1 day or less
- Funding
- No external funding declared
- Conflicts of interest
- None declared
- Outcome
- Positive
- Peer Reviewed
- Yes
- Cited by
- 10 (OpenAlex, as of November 2026)
- Country
- Japan
TL;DR
Breathing in hydrogen gas while exercising may boost fat burning without affecting stress on the body or fat metabolism at rest.
Key Finding
Inhaling 1% molecular hydrogen gas significantly increased breath acetone levels and oxygen uptake during moderate-intensity cycling exercise, suggesting enhanced fat metabolism during physical activity.
Summary
This study tested whether breathing in molecular hydrogen gas could help the body burn more fat during exercise. Ten men cycled at moderate intensity while inhaling either hydrogen gas or a control gas, and researchers measured acetone in their breath as a sign of fat burning. The results showed that hydrogen inhalation increased breath acetone levels and oxygen use during exercise, suggesting the body was burning more fat, but it had no effect when people were resting.
Practical Takeaway
This small study (10 participants) suggests hydrogen gas inhalation may support fat burning specifically during exercise, though the practical benefit remains unclear. The effect only appeared during exercise, not at rest, and the study did not measure actual weight loss or long-term health outcomes. More research with larger groups and longer follow-up is needed before drawing conclusions about real-world usefulness.
Abstract (excerpt)
Aerobic exercise is widely accepted as a beneficial option for reducing fat in humans. Recently, it has been suggested that molecular hydrogen (H2) augments mitochondrial oxidative phosphorylation. Therefore, the hypothesis that inhaling H2 could facilitate lipid metabolism during aerobic exercise…