Aoki, K.; Nakao, A.; Adachi, T.; Matsui, Y.; Miyakawa, S.
Source: Medical Gas Research, Volume 2, Article 12 (2012)

Background:
Muscle contraction during short intervals of intense exercise induces oxidative stress, which may contribute to the development of overtraining symptoms, including increased fatigue, microtrauma, or muscle inflammation. Recent studies have suggested that hydrogen may act as an antioxidant. Therefore, this study investigated the effects of hydrogen-rich water (HW) on oxidative stress and muscle fatigue in response to acute exercise.

Methods:
Ten football players (mean age 20.9 ± 1.3 years) underwent exercise testing and blood sampling. Each subject participated in a double-blind, cross-over trial where they consumed either HW or placebo water (PW) in weekly intervals. Subjects exercised on a cycle ergometer at 75% of their maximal oxygen uptake (VO₂ max) for 30 minutes, followed by measurements of peak torque and muscle activity during 100 repetitions of maximal isokinetic knee extension. Peripheral blood was assessed for markers of oxidative stress and creatine kinase levels.

Results:
While acute exercise led to a significant increase in blood lactate levels in the PW group, oral intake of HW prevented this rise during strenuous exercise. In the PW group, peak torque declined significantly during maximal isokinetic knee extension—indicating muscle fatigue—whereas in the HW group, peak torque remained stable in the early phase. No significant post-exercise changes were observed in blood oxidative damage markers (d-ROM and BAP) or creatine kinase levels.

Conclusion:
Adequate hydration with hydrogen-rich water before exercise reduced blood lactate accumulation and mitigated exercise-induced decline in muscle function. Although further studies are required to clarify the mechanisms and benefits in larger populations, these preliminary results suggest that HW may be a suitable hydration strategy for athletes.

Citation:
Aoki K., Nakao A., Adachi T., Matsui Y., Miyakawa S. (2012). Pilot study: Effects of drinking hydrogen-rich water on muscle fatigue caused by acute exercise in elite athletes. Medical Gas Research, 2, 12.
https://doi.org/10.1186/2045-9912-2-12
PMID: 22520831; PMCID: PMC3395574

Botek, M.; Khanna, D.; Krejčí, J.; Valenta, M.; McKune, A.; Sládečková, B.; Klimešová, I.
Source: Nutrients, Volume 14, Issue 3 (2022)

Background:
Supplementation with hydrogen-rich water (HRW) has been shown to exert anti-fatigue effects across various exercise modalities. However, its impact on repeated sprint performance remains unclear.

Objective:
The aim of this study was to evaluate the effect of pre-exercise HRW consumption on repeated sprint performance, blood lactate levels, and perceived exertion using a repeated sprint protocol.

Methods:
This randomised, double-blind, placebo-controlled, crossover study included 16 professional male soccer players (mean age: 18.8 ± 1.2 years). Athletes completed two indoor repeated sprint tests, consisting of fifteen 30-metre sprints with 20 seconds of passive recovery between sprints, separated by a one-week washout period. Sprint times were recorded at both 15 metres and 30 metres. Ratings of perceived exertion (RPE) were assessed immediately after each sprint, and post-exercise blood lactate levels were measured after the final sprint.

Results:
Sprint times at 15 metres were significantly faster during the 14th and 15th sprints following HRW ingestion compared to placebo, representing improvements of 3.4% and 2.7%, respectively. The 30-metre sprint time also improved significantly by 1.9% in the final sprint in the HRW group. However, no significant differences were found between HRW and placebo groups in post-exercise blood lactate concentrations or RPE.

Conclusion:
Pre-exercise HRW supplementation was associated with enhanced fatigue resistance, particularly during the latter stages of repeated sprint exercise. These findings suggest a potential ergogenic benefit of HRW in high-intensity intermittent sports performance.

Citation:
Botek, M., Khanna, D., Krejčí, J., Valenta, M., McKune, A., Sládečková, B., & Klimešová, I. (2022). Molecular hydrogen mitigates performance decrement during repeated sprints in professional soccer players. Nutrients, 14(3), 508.
https://doi.org/10.3390/nu14030508

Botek, M.; Krejčí, J.; McKune, A.; Sládečková, B.
Source: International Journal of Sports Physiology and Performance, Volume 15, Issue 8 (2020)

Background:
Hydrogen-rich water (HRW) has been demonstrated to exert anti-fatigue effects.

Objective:
This study evaluated uphill running performance as well as physiological and perceptual responses following supplementation with 1680 mL of HRW consumed between 24 hours and 40 minutes prior to exercise in athletes with heterogeneous running capacities.

Methods:
Sixteen males (mean age 31.6 ± 8.6 years, VO₂ max 57.2 ± 8.9 mL·kg⁻¹·min⁻¹, body fat 13.4% ± 4.4%) participated in this randomised, double-blind, placebo-controlled crossover study. Participants consumed either HRW or placebo before completing two 4.2-km uphill running trials spaced one week apart. Race time (RT), average heart rate during the trial, and post-race ratings of perceived exertion (RPE) were recorded.

Results:
Across all participants, the effect of HRW on RT was unclear (−10 to +7 seconds; 90% confidence interval), likely trivial for heart rate (−2 to +3 beats·min⁻¹), and likely trivial for post-race RPE (−0.1 to +1.0). A possible negative correlation was observed between RT differences and mean RT (r = −0.79 to −0.15). HRW appeared to improve RT in the four slowest runners (RT = 1490 ± 91 s) by −36 to −3 seconds, whereas the effect in the four fastest runners (RT = 1069 ± 53 s) was unclear (−10 to +26 seconds).

Conclusion:
Overall, HRW intake showed an unclear anti-fatigue effect on performance based on average group values. However, the magnitude of HRW’s performance benefit may depend on individual running capacity, suggesting a potentially greater effect in lower-performing athletes.

Citation:
Botek, M., Krejčí, J., McKune, A. J., & Sládečková, B. (2020). Hydrogen-rich water supplementation and up-hill running performance: Effect of athlete performance level. International Journal of Sports Physiology and Performance, 15(8), 1193–1196.
https://doi.org/10.1123/ijspp.2019-0507

Sládečková, B.; Botek, M.; Krejčí, J.; Valenta, M.; McKune, A.; Neuls, F.; Klimešová, I.
Source: Frontiers in Physiology, Volume 15 (2024)

Background:
Molecular hydrogen has demonstrated antioxidant, anti-inflammatory, ergogenic, and recovery-enhancing effects.

Objective:
This study aimed to evaluate the effects of molecular hydrogen supplementation on muscle performance, muscle damage, and perceived soreness during a 24-hour recovery period following two strenuous training sessions performed on the same day in elite fin swimmers.

Methods:
Eight female (mean ± SD; age: 21.5 ± 5.0 years, VO₂ max: 45.0 ± 2.5 mL·kg⁻¹·min⁻¹) and four male (age: 18.9 ± 1.3 years, VO₂ max: 52.2 ± 1.7 mL·kg⁻¹·min⁻¹) elite fin swimmers completed two sessions: a morning set of 12 × 50 m sprints and an afternoon competitive 400 m swim. Participants consumed either hydrogen-rich water (HRW) or placebo water for three days prior to testing (1,260 mL/day) and 2,520 mL on the experimental day. Muscle performance (countermovement jump height), muscle damage (creatine kinase activity), and muscle soreness (100 mm visual analogue scale) were assessed during the experimental day and 12 and 24 hours post-exercise.

Results:
Compared with placebo, HRW supplementation significantly reduced post-exercise creatine kinase levels (156 ± 63 vs. 190 ± 64 U·L⁻¹; p = 0.043), muscle soreness (34 ± 12 vs. 42 ± 12 mm; p = 0.045), and improved countermovement jump height (30.7 ± 5.5 cm vs. 29.8 ± 5.8 cm; p = 0.014) at 12 hours after the afternoon training session.

Conclusion:
Four days of HRW supplementation represents a promising hydration strategy to enhance muscle recovery following two strenuous training sessions on the same day in elite fin swimmers.

Citation:
Sládečková, B., Botek, M., Krejčí, J., Valenta, M., McKune, A., Neuls, F., & Klimešová, I. (2024). Hydrogen-rich water supplementation promotes muscle recovery after two strenuous training sessions performed on the same day in elite fin swimmers: randomised, double-blind, placebo-controlled, crossover trial. Frontiers in Physiology, 15, 1321160.
https://doi.org/10.3389/fphys.2024.1321160

Timón, R.; Olcina, G.; González-Custodio, A.; Camacho-Cardenosa, M.; Camacho-Cardenosa, A.; Guardado, I.M.
Source: Biology of Sport, Volume 38, Issue 2 (2021)

Background:
Hydrogen-rich water (HRW) has been used as a supplement to improve performance and reduce fatigue in athletes. However, its potential beneficial effects may be mediated by the subject’s training status.

Objective:
The purpose of this study was to analyse the ergogenic effect of a 7-day intake of HRW on both aerobic and anaerobic performance in trained and untrained individuals.

Methods:
A total of 37 volunteers participated and were divided into two experimental groups: trained cyclists and untrained subjects. A double-blind crossover design was employed, in which all participants consumed both placebo water (PW) and nanobubble-form HRW (pH 7.5; hydrogen concentration: 1.9 ppm; oxidation-reduction potential [ORP]: −600 mV). At the end of each 7-day supplementation period, performance was evaluated via an incremental VO₂max test and a maximal anaerobic test.

Results:
Following HRW intake, only trained cyclists showed improved performance in the anaerobic test, with an increase in peak power output (from 766.2 ± 125.6 W to 826.5 ± 143.4 W; Cohen’s d = 0.51), average power output (from 350.0 ± 53.5 W to 380.2 ± 71.3 W; d = 0.51), and a reduction in the fatigue index (from 77.6 ± 5.8% to 75.1 ± 5.9%; d = 0.45).

Conclusion:
These findings suggest that the ergogenic effect of HRW is influenced by training status. A 7-day supplementation regimen with HRW may serve as an effective strategy to enhance anaerobic performance in trained cyclists.

Citation:
Timón, R., Olcina, G., González-Custodio, A., Camacho-Cardenosa, M., Camacho-Cardenosa, A., & Guardado, I.M. (2021). Effects of 7-day intake of hydrogen-rich water on physical performance of trained and untrained subjects. Biology of Sport, 38(2), 269.
https://doi.org/10.5114/biolsport.2021.100142

Sha, J.B.; Zhang, S.S.; Lu, Y.M.; Gong, W.J.; Jiang, X.P.; Wang, J.J.; Qiao, T.L.; Zhang, H.H.; Zhao, M.Q.; Wang, D.P.; Xia, H.; Li, Z.W.; Chen, J.L.; Zhang, L.; Zhang, C.G.
Source: Medical Gas Research, Volume 8, Issue 4 (2019)

Background:
Expenditure of significant physical energy inevitably leads to fatigue during football training and competition. An increasing number of experimental findings have confirmed the relationship between the generation and elimination of free radicals, fatigue, and exercise-induced injury. Recently, hydrogen has been identified as a novel selective antioxidant with potential benefits in sports applications.

Objective:
This study evaluated the effects of a 2-month consumption of hydrogen-rich water (HRW) on gut microbiota in female juvenile soccer players from Suzhou, China.

Results:
According to enzyme-linked immunoassays and 16S rDNA sequencing of stool samples, the two-month consumption of HRW significantly decreased serum levels of malondialdehyde (MDA), interleukin-1 (IL-1), interleukin-6 (IL-6), and tumour necrosis factor-alpha (TNF-α). It also significantly increased serum levels of superoxide dismutase (SOD), total antioxidant capacity (T-AOC), and haemoglobin in whole blood. Furthermore, HRW consumption improved the diversity and abundance of the gut microbiota in the athletes. All microbial diversity indices studied—including Shannon, Simpson, ACE, and Chao1—were initially lower in the HRW group compared to controls prior to the intervention, but after two months, these indices increased and surpassed those of the control group. However, while there were some differences in microbiota composition between groups at baseline, no significant compositional changes were observed during the trial period.

Conclusion:
Thus, two months of hydrogen-rich water consumption may play a role in modulating gut microbiota in athletes, likely via its selective antioxidant and anti-inflammatory effects.

Citation:
Sha, J.B., Zhang, S.S., Lu, Y.M., et al. (2019). Effects of the long-term consumption of hydrogen-rich water on the antioxidant activity and the gut flora in female juvenile soccer players from Suzhou, China. Medical Gas Research, 8(4), 135–143.
https://doi.org/10.4103/2045-9912.248263

Drid, P.; Trivic, T.; Casals, C.; Trivic, S.; Stojanovic, M.; Ostojic, S.M.
Source: Science & Sports, Volume 31, Issue 4 (2016)

Objective:
The aim of this double-blind, randomised, placebo-controlled crossover study was to determine the effects of pre-exercise hydrogen-rich water (HRW) intake on biomarkers of acid–base homeostasis and post-exercise recovery in female athletes.

Methods:
Eight young female judo athletes (mean age 21.4 ± 2.2 years) were randomly assigned to consume either HRW or placebo water 30 minutes before exercise. The same procedures were repeated four days later in a crossover design. The exercise protocol consisted of high-intensity intermittent effort using a judo-specific performance test. Heart rate was recorded before and after exercise. Arterial blood was sampled to determine pH, bicarbonate, and lactate levels at rest (pre-intervention), and at 3 and 5 minutes post-exercise.

Results:
HRW intake significantly influenced post-exercise blood pH and lactate levels compared to placebo (p < 0.05), whereas no significant difference was observed in the serum bicarbonate response between interventions. No differences were found between HRW and placebo with respect to heart rate response. No adverse effects were reported for either intervention.

Conclusion:
Hydrogen-rich water may serve as an appropriate and safe hydration strategy to help athletes become less susceptible to exercise-induced acidosis.

Citation:
Drid, P., Trivic, T., Casals, C., Trivic, S., Stojanovic, M., & Ostojic, S.M. (2016). Is molecular hydrogen beneficial to enhance post-exercise recovery in female athletes? Science & Sports, 31(4), 207–213.
https://doi.org/10.1016/j.scispo.2016.06.004

Dong, G.X.; Fu, J.H.; Bao, D.P.; Zhou, J.H.
Source: International Journal of Environmental Research and Public Health, Volume 19, Issue 9 (2022)

Background:
Exercise that exceeds the body’s usual load can lead to oxidative stress and increased fatigue during intense training or competition, potentially resulting in reduced performance and a higher risk of injury. Molecular hydrogen (H₂) has recently emerged as a promising antioxidant that may offer protective effects.

Objective:
This study investigated the effects of short-term hydrogen-rich water (HRW) supplementation on power output and post-exercise recovery in dragon boat athletes.

Methods:
Eighteen dragon boat athletes, training four hours daily (two hours in the morning and two in the afternoon), were randomly assigned to either an HRW group (n = 9) or a placebo water (PW) group (n = 9). Participants consumed HRW or PW daily for seven days. All athletes completed a 30-second rowing ergometer test on day 1 and again on day 8, with heart rate monitoring before, during, and after the test.

Results:
HRW consumption significantly increased both peak and average power during the 30-second rowing test and reduced peak heart rate during exertion. Furthermore, heart rate in the HRW group decreased significantly within two minutes of recovery post-exercise, whereas no reduction was observed in the PW group. There was no significant difference between groups in rowing distance achieved in 30 seconds or the estimated time for a 500 m effort.

Conclusion:
Short-term consumption of HRW can effectively enhance performance and improve heart rate recovery following exercise in dragon boat athletes, suggesting its potential as a beneficial hydration strategy for athletes.

Citation:
Dong, G., Fu, J., Bao, D., & Zhou, J. (2022). Short-term consumption of hydrogen-rich water enhances power performance and heart rate recovery in dragon boat athletes: Evidence from a pilot study. International Journal of Environmental Research and Public Health, 19(9), 5413.
https://doi.org/10.3390/ijerph19095413