Inhalation of Hydrogen-rich Gas before Acute Exercise Alleviates Exercise Fatigue: A Randomized Crossover Study
Dong G, Wu J, Hong Y, Li Q, Liu M, Jiang G, Bao D, Manor B, Zhou J. · Int J Sports Med. 2024;45(13):1014-1022.
Study at a glance
In 24 healthy young men, hydrogen–oxygen inhalation before cycling reduced immediate feelings of fatigue and helped maintain cadence at the end of a fixed-duration exercise task. Jump performance did not improve significantly, and several blood measurements were unchanged. The study did not measure the hydrogen concentration actually breathed in.
Human
24 healthy recreationally active men; mean age 21 ± 3 years.
Hydrogen–oxygen Convalescent machine 2.5 (Zhiheng Hydrogen Health Technology, Fuzhou) via nasal cannula for 60 minutes before a fixed-duration cycling fatigue challenge at 80% Wmax. · Authors estimated inspired fractions of 4.08% H₂ and 21.66% O₂; these were not measured.
60 minutes of inhalation before exercise; assessments immediately, 30 minutes and 60 minutes after exercise.
Fatigue VAS group-by-time P = 0.019; immediately after exercise, 72.5 (55.0, 80.1) versus 76.8 (68.0, 89.0) mm (P = 0.008), but no significant difference at 30/60 minutes (P > 0.258). RPE was 9.0 (9.0, 10.0) versus 10.5 (10.0, 11.0), P < 0.001. CMJ group-by-time F = 2.723, P = 0.113: no significant improvement despite numerical values of 35.01 versus 32.53 cm. Last-30-second cadence was 65.38 ± 3.96 versus 53.45 ± 3.97 rpm (P < 0.001); earlier segments were 60–70 rpm in both conditions. Immediate lactate was 8.49 ± 3.37 versus 9.96 ± 2.86 mmol/L (P = 0.058); at 30 minutes, 2.60 ± 1.08 versus 3.46 ± 1.02, and at 60 minutes, 1.95 ± 0.75 versus 2.49 ± 0.85 (P < 0.028). Immediate hydroxyl-radical-inhibition assay values were 637.06 ± 222.43 versus 434.69 ± 201.67 U/mL (P = 0.009), with later comparisons nonsignificant. GSH-PX interaction P = 0.815; biomarker/fatigue correlations were nonsignificant (r < 0.245, P > 0.271).
Only 24 young men and an acute protocol. Inspired fractions were estimated and oxygen differed between conditions. CMJ was null and the subjective fatigue difference was transient. Multiple endpoints/time points, Fisher LSD comparisons and lactate freezing at −80 °C limit interpretation. Assay validity and a causal link between biomarker changes and fatigue remain uncertain.
What kind of evidence is this?
Human
Randomized, double-blind, counterbalanced crossover study; 12 initially assigned to each sequence, with at least 7 days of washout.
Exercise and recovery
Inhaled H₂
Information not yet classified
Some editorial classification fields are still pending. The source-reported outcomes and result are shown below; Hydrogenology does not infer a positive or negative signal from prose automatically.
Methods
24 healthy recreationally active men; mean age 21 ± 3 years.
24 recruited; all 24 completed the tests and were analyzed.
60 minutes of inhalation before exercise; assessments immediately, 30 minutes and 60 minutes after exercise.
Hydrogen–oxygen Convalescent machine 2.5 (Zhiheng Hydrogen Health Technology, Fuzhou) via nasal cannula for 60 minutes before a fixed-duration cycling fatigue challenge at 80% Wmax.
Hydrogen–oxygen source mixture, H₂:O₂ = 2:1.
Authors estimated inspired fractions of 4.08% H₂ and 21.66% O₂; these were not measured.
Reported combined source-gas flow 1,800 mL/min. The 1,200 mL/min H₂ component is calculated from the 2:1 mixture, not a measured patient dose.
O₂ is included in the 2:1 H₂/O₂ mixture. Estimated inspired O₂ was 21.66%, not measured; the ambient-air control was not exactly oxygen matched.
Ambient air through an identical nasal cannula, with the generator hydrogen program off.
Outcomes and reported result
Fatigue-perception VAS and countermovement jump (CMJ), with secondary cycling-cadence and biochemical outcomes. The exercise task had a fixed duration, not a time-to-exhaustion endpoint.
Fatigue VAS group-by-time P = 0.019; immediately after exercise, 72.5 (55.0, 80.1) versus 76.8 (68.0, 89.0) mm (P = 0.008), but no significant difference at 30/60 minutes (P > 0.258). RPE was 9.0 (9.0, 10.0) versus 10.5 (10.0, 11.0), P < 0.001. CMJ group-by-time F = 2.723, P = 0.113: no significant improvement despite numerical values of 35.01 versus 32.53 cm. Last-30-second cadence was 65.38 ± 3.96 versus 53.45 ± 3.97 rpm (P < 0.001); earlier segments were 60–70 rpm in both conditions. Immediate lactate was 8.49 ± 3.37 versus 9.96 ± 2.86 mmol/L (P = 0.058); at 30 minutes, 2.60 ± 1.08 versus 3.46 ± 1.02, and at 60 minutes, 1.95 ± 0.75 versus 2.49 ± 0.85 (P < 0.028). Immediate hydroxyl-radical-inhibition assay values were 637.06 ± 222.43 versus 434.69 ± 201.67 U/mL (P = 0.009), with later comparisons nonsignificant. GSH-PX interaction P = 0.815; biomarker/fatigue correlations were nonsignificant (r < 0.245, P > 0.271).
The available main full text was reviewed for methods, results, limitations and declarations. Uncertainties, supplementary-source limits and conflicting findings are stated in this record.
Dedicated systematic adverse-event results were not identified. Participants reported indistinguishable inhalation sensations; this does not establish absence of adverse events.
A reported association, difference or mechanism is not automatically a clinical benefit.
Limitations and applicability
Only 24 young men and an acute protocol. Inspired fractions were estimated and oxygen differed between conditions. CMJ was null and the subjective fatigue difference was transient. Multiple endpoints/time points, Fisher LSD comparisons and lactate freezing at −80 °C limit interpretation. Assay validity and a causal link between biomarker changes and fatigue remain uncertain.
Acute exercise responses in young recreationally active men; no proven endurance-to-exhaustion, training or clinical benefit.
No separate funding statement was identified in the complete publisher article. The equipment manufacturer is named; a donation was not established.
Authors declare no conflict of interest.
No single-study GRADE certainty rating is assigned. Read how records and evidence assessments are prepared.
Sources and record status
PMID: 38698624 · DOI: 10.1055/a-2318-1880
Complete final publisher article in Thieme HTML, including Tables 1–3 and figure captions. The supplementary methods PDF was not separately checked.
AI-assisted editorial review of the available main full text, 29 October 2026. No independent clinical or statistical assessment has been performed.
Participants and protocol; hydrogen-rich gas; measurements/statistics; all Results subsections; Tables 1–3; Discussion/limitations; conflict statement.
AI-assisted editorial review of the available main full text, 29 October 2026. Complete final publisher article in Thieme HTML, including Tables 1–3 and figure captions. The supplementary methods PDF was not separately checked.
The article reports ethics approval 2021163H. A matching-title registry entry, ChiCTR2500095599, was posted on 9 January 2025 after the 2024 publication; its definitive link to this study was not established.
29 October 2026
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