"Oxygenated" water and athletic performance

Health effects of alkaline, oxygenated, and demineralized water compared to mineral water among healthy population: a systematic review

OBJECTIVES

There are many water types available on the market. They are widely known in public with health claims. The questions are, are those claims are scientifically proven or those are just testimonies from the consumers or overclaimed by the producers. This study aims to systematically review evidences on the health effects of alkaline, oxygenated, and demineralized water in comparison with mineral water among healthy population.

CONTENTS

Data were obtained from databases PubMed, Cochrane, Scopus, EBSCO, dan Science Direct since January 2000 until July 2022. There were 10 eligible articles, consisted of two articles on alkaline, four articles on oxygenated, and four articles on demineralized water, that furtherly being analyzed.

SUMMARY

Compared to consumption of mineral water, consumption of alkaline and oxygenated water did not show any significant difference on gut microbiota, urine pH, blood parameter, or fitness parameter. While, consumption of demineralized water in the long term resulted in lower quality of certain nutrient intake.

OUTLOOK

Recent evidences do not prove any additional health effects of alkaline, oxygenated, or demineralized water compared to mineral water. In contrast, demineralized water consumption in the long run was proven to lead to adverse effect.

A Double-Blind, Randomized, Placebo-Controlled Pilot Study examining an Oxygen Nanobubble Beverage for 16.1-km Time Trial and Repeated Sprint Cycling Performance

There is growing interest of ergogenic aids that deliver supplemental oxygen during exercise and recovery, however, breathing supplemental oxygen via specialist facemasks is often not feasible. Therefore, this study investigated the effect of an oxygen-nanobubble beverage during submaximal and repeated sprint cycling. In a double-blind, randomized, placebo-controlled study, 10 male cyclists (peak aerobic capacity, 56.9 ± 6.1 mL·kg-1·min-1; maximal aerobic power, 385 ± 25 W) completed submaximal or maximal exercise after consuming an oxygen-nanobubble (O2) or placebo (PLA) beverage. Submaximal trials comprised 30-min of steady-state cycling at 60% peak aerobic capacity and 16.1-km time-trial (TT). Maximal trials involved 4 × 30 s Wingate tests interspersed by 4-min recovery. Time-to-completion during the 16.1-km TT was 2.4% faster after O2 compared with PLA (95% CI = 0.7-4.0%, p = 0.010, d = 0.41). Average power for the 16.1-km TT was 4.1% higher for O2 vs. PLA (95% CI = 2.1-7.3%, p = 0.006, d = 0.28). Average peak power during the repeated Wingate tests increased by 7.1% for O2 compared with PLA (p = 0.002, d = 0.58). An oxygen-nanobubble beverage improves performance during submaximal and repeated sprint cycling, therefore may provide a practical and effective ergogenic aid for competitive cyclists.

Oxygenated Water Increases Seizure Threshold in Various Rodent Seizure Models

Oxygenated water (OW) contains more oxygen than normal drinking water. It may induce oxygen enrichment in the blood and reduce oxidative stress. Hypoxia and oxidative stress could be involved in epilepsy. We aimed to examine the effects of OW-treated vs. control on four rodent models of epilepsy: (1) prenatal betamethasone priming with postnatal N-methyl-D-aspartate (NMDA)-triggered spasm, (2) no prenatal betamethasone, (3) repetitive kainate injection, and (4) intraperitoneal pilocarpine. We evaluated, in (1) and (2), the latency to onset and the total number of spasms; (3) the number of kainate injections required to induce epileptic seizures; (4) spontaneous recurrent seizures (SRS) (numbers and duration). In model (1), the OW-treated group showed significantly increased latency to onset and a decreased total number of spasms; in (2), OW completely inhibited spasms; in (3), the OW-treated group showed a significantly decreased number of injections required to induce epileptic seizures; and in (4), in the OW-treated group, the duration of a single SRS was significantly reduced. In summary, OW may increase the seizure threshold. Although the underlying mechanism remains unclear, OW may provide an adjunctive alternative for patients with refractory epilepsy.

Effects of Drinking Oxygenated Water on Blood Oxygen Saturation During Exercise Under Normobaric Hypoxic Conditions: A Randomized Placebo-controlled Single-blinded Trial

Objectives

This study aimed to investigate the effects of drinking oxygenated water on oxygen saturation during exercise under normobaric hypoxic conditions.

Materials

A randomized placebo-controlled single-blinded trial was performed. Twenty-two healthy adults (16 men and 6 women), with a mean age (standard deviation) of 22.4 (2.73) years, participated in the study. The participants were randomly assigned to one of two groups: an OX group (drinking oxygenated mineral water) and a control group (drinking normal mineral water). Both groups performed walking exercises under normobaric hypoxic conditions. Blood oxygen saturation (SpO2), pulse rate (PR), and walking distance were measured during exercise.

Results

SpO2 decreased and PR increased during exercise in both groups. The decrease in SpO2 was smaller and the increase in PR was greater in the OX group compared with those in the control group. No significant difference was found in walking distance between the two groups.

Conclusions

Drinking oxygenated water before exercise may inhibit SpO2 reduction under normobaric hypoxic conditions.

Effect of Waters Enriched in O2 by Injection or Electrolysis on Performance and the Cardiopulmonary and Acid-Base Response to High Intensity Exercise

Several brands of water enriched with O₂ (O₂-waters) are commercially available and are advertised as wellness and fitness waters with claims of physiological and psychological benefits, including improvement in exercise performance. However, these claims are based, at best, on anecdotal evidence or on a limited number of unreliable studies. The purpose of this double-blind randomized study was to compare the effect of two O₂-waters (~110 mg O₂·L^-1) and a placebo (10 mg O₂·L^-1, i.e., close to the value at sea level, 9-12 mg O₂·L^-1) on the cardiopulmonary responses and on performance during high-intensity exercise. One of the two O₂-waters and the placebo were prepared by injection of O₂. The other O₂-water was enriched by an electrolytic process. Twenty male subjects were randomly allocated to drink one of the three waters in a crossover study (2 L·day^-1 × 2 days and 15 mL·kg^-1 90 min before exercise). During each exercise trial, the subjects exercised at 95.9 ± 4.7% of maximal workload to volitional fatigue. Exercise time to exhaustion and the cardiopulmonary responses, arterial lactate concentration and pH were measured. Oxidative damage to proteins, lipids and DNA in blood was assessed at rest before exercise. Time to exhaustion (one-way ANOVA) and the responses to exercise (two-way ANOVA [Time; Waters] with repeated measurements) were not significantly different among the three waters. There was only a trend (p = 0.060) for a reduction in the time constant of the rapid component of VO₂ kinetics with the water enriched in O₂ by electrolysis. No difference in oxidative damage in blood was observed between the three waters. These results suggest that O₂-water does not speed up cardiopulmonary response to exercise, does not increase performance and does not trigger oxidative stress measured at rest.

On the Apparent Redox Reactivity of "Oxygen-Enriched Water"

Molecular oxygen-enriched water (OxEW) is advocated in popular media as useful for various health issues, presumably due to involvement of a purported antioxidant activity and to such notions as "active oxygen." To our knowledge, there are no explicit reports in the scientific literature where such redox reactivity would be described and explained. Reported here are data showing that a commercial preparation of OxEW does display a measurable, albeit very small, antioxidant activity as monitored by reaction with a standard reagent, DPPH. Moreover, OxEW also displays an apparent pro-oxidant reactivity, against caffeic acid. This does not correlate with any UV-vis-detectable contents of chemical substances in the water, nor can it be explained by typical chemical impurities (e.g., hydrogen peroxide or molecular hydrogen) that would arise upon enrichment with molecular oxygen of pure water by the two most common procedures: purging with gaseous O₂ or electrolysis. Instead, this apparent redox reactivity is revealed to be due to differences in pH and in chemical content - and the differences in turn are most likely due to the trace amounts of inorganic ions/elements in the OxEW; importantly, electrolysis, which is often employed as a means to generate O₂ in OxEW preparation, is also found to enhance the redox effect of OxEW-like preparations. Thus, in line with expectations, the herein-reported data show that there are no long-lived reactive oxygen species, no activated oxygen, and no extra reducing agents in OxEW - but that an apparent weak redox reactivity can still be measured and assigned to simple side effects of the electrolysis procedure presumably performed in order to enrich the sample in oxygen.

Effect of Drinking Oxygenated Water Assessed by in vivo MRI Relaxometry

GRANT SUPPORT

This project was funded by the Research Council of Norway.

BACKGROUND

Oxygen uptake through the gastrointestinal tract after oral administration of oxygenated water in humans is not well studied and is debated in the literature. Due to the paramagnetic properties of oxygen and deoxyhemoglobin, MRI as a technique might be able to detect changes in relaxometry values caused by increased oxygen levels in the blood.

PURPOSE

To assess whether oxygen dissolved in water is absorbed from the gastrointestinal tract and transported into the bloodstream after oral administration.

STUDY TYPE

A randomized, double-blinded, placebo-controlled crossover trial.

POPULATION/SUBJECTS

Thirty healthy male volunteers age 20-35.

FIELD STRENGTH/SEQUENCE

3T/Modified Look-Locker inversion recovery (MOLLI) T₁ -mapping and multi fast field echo (mFFE) T₂ *-mapping.

ASSESSMENT

Each volunteer was scanned in two separate sessions. T₁ and T₂ * maps were acquired repeatedly covering the hepatic portal vein (HPV) and vena cava inferior (VCI, control vein) before and after intake of oxygenated or control water. Assessments were done by placing a region of interest in the HPV and VCI.

STATISTICAL TEST

A mixed linear model was performed to the compare control vs. oxygen group.

RESULTS

Drinking caused a mean 1.6% 95% CI (1.1-2.0% P < 0.001) increase in T₁ of HPV blood and water oxygenation attributed another 0.70% 95% confidence interval (CI) (0.07-1.3% P = 0.028) increase. Oxygenation did not change T₁ in VCI blood. Mean T₂ * increased 9.6% 95% CI (1.7-17.5% P = 0.017) after ingestion of oxygenated water and 1.2% 95% CI (-4.3-6.8% P = 0.661) after ingestion of control water. The corresponding changes in VCI blood were not significant.

DATA CONCLUSION

Ingestion of water caused changes in T₁ and T₂ * of HPV blood compatible with dilution due to water absorption. The effects were enhanced by oxygen. Assessment of oxygen enrichment of HPV blood was not possible due to the dilution effect.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY STAGE: 2 J. Magn. Reson. Imaging 2020;52:720-728.

Ingestion of oxygenated water enhances lactate clearance kinetics in trained runners

BACKGROUND

Drinks with higher dissolved oxygen concentrations have in recent times gained popularity as a potential ergogenic aid, despite a lack of evidence regarding their efficacy. The aim of this study was to assess effects of ingestion of an oxygen supplement (OS) on exercise performance and post-exercise recovery in a group of trained runners.

METHODS

Trained male runners (n = 25, mean ± SD; age 23 ± 6 years, mass 70 ± 9 kg, BMI 21.9 ± 2.7 kg.m-2 VO2max 64 ± 6mL.kg-1.min-1), completed a randomised double blinded, crossover study to assess the effect of ingestion of OS solution on exercise performance and recovery. Trials consisted of a 30min rest period, 5min warm-up, a 5000m treadmill time-trial, and a 30min passive recovery. Participants ingested 6x15mL of either OS or a taste matched placebo during the trials (3 during the rest phase, 1 during exercise and 2 during the recovery). Muscle tissue O2 saturation was measured via near infrared spectroscopy. Blood lactate concentrations were measured prior to, mid-way and directly after the finish of the 5000m time trials and every 3-min during the post-exercise recovery.

RESULTS

Ingestion of OS did not improve exercise performance. No significant differences were observed for muscle tissue O2 saturation at any time-points. However, lactate clearance was significantly improved during recovery in the OS trials. Both AUC (109 ± 32 vs. 123 ± 38 mmol.min, P < 0.05, d = 0.40) and lactate half-life (λ) (1127 ± 272 vs. 1223 ± 334 s, P < 0.05, d = 0.32) were significantly reduced.

CONCLUSIONS

Despite no evidence of improved exercise performance, ingestion of OS did enhance post-exercise recovery via increased lactate clearance.