Hydrogen inhalation improves endurance in athletesScientific Research

Hydrogen inhalation improves endurance in athletes

Abstract

In this randomized, double-blind, placebo-controlled, crossover pilot study, we evaluated the effects of 7-day inhalation of H 2 on exercise performance and serum hormonal and inflammatory profiles in a cohort of young men and women. All participants (age 22.9 ± 1.5 years; body mass index 23.4 ± 2.5 kg m -2 ; 10 women and 10 men) were assigned to receive hydrogen gas (4%) or placebo (room air ) by 20-minute inhalation once daily for 7 days, with a washout period of 7 days to prevent residual effects of the interventions during the study periods.

The primary outcome of therapy was the change in time to exhaustion of the incremental maximal test from baseline to day seven. In addition, assessment of other end points for exercise performance and clinical chemistry biomarkers was performed at baseline and on day seven after each intervention. The trial is registered at ClinicalTrials.gov (ID NCT03846141 ). Breathing 4% hydrogen for 20 minutes per day resulted in increased peak locomotor velocity (by up to 4.2%) compared with breathing air ( P = 0.05). Hydrogen inhalation resulted in a marked drop in serum insulin-like growth factor-1 (IGF-1) by 48.2 ng/ml at follow-up (95% confidence interval [CI]: -186.7 to 89.3) ( P <0 .05), whereas IGF-1 levels were increased by 59.3 ng/mL after the placebo intervention (95% CI; from -110.7 to 229.5) ( P < 0.05). Inhaled hydrogen appears to exhibit ergogenic properties in healthy men and women. Gaseous H 2 needs to be further evaluated for its efficacy and safety in an athletic setting.

Introduction

The use of medicinal gases has recently been described as an emerging strategy in the exercise physiology and sports medicine community [1], with several non-traditional medicinal gases (such as NO, Xe, O 3 ) proposed as performance enhancers.

Molecular hydrogen (H 2 ) is a gas that can be administered to athletes to increase their endurance. Commonly administered as a dietary supplement, either as hydrogen water or tablets, H 2 appears to positively affect physical performance in both animal studies [2–4] and human studies [5–8]. This may be due to its antioxidant and anti-inflammatory properties [9], which perhaps reduce exercise-induced inflammation and oxidative stress or by altering the production of anabolic hormones through signal modulation [10, 11]. For example, Aoki and colleagues [ 5 ] reported that hydration with 1.5 L daily of hydrogen-rich water (0.92–1.02 mM hydrogen) significantly reduced blood lactate levels and improved the induced decline in muscle function in male soccer players during exercise.

The buffering capacity of hydrogen-rich water (1.1 mM) during exercise-induced acidosis has also been demonstrated after both continuous [ 6 ] and progressive running to exhaustion [ 7 ]. A two-week intake of hydrogen-rich water (2 L per day, 0.45 mM free hydrogen) helps maintain peak power in repeated sprints to exhaustion over 30 min in male cyclists [ 8 ].

Although the above preliminary studies provided initial evidence regarding the capacity to perform an increase in hydrogen-rich water, the question remains open whether the beneficial effects originate from H 2 itself or perhaps from magnesium, a conventional source of hydrogen in hydrogen-rich water. Specifically, the apparent buffering capacity of hydrogen-rich water may be due to various pH buffers (e.g., bicarbonate, magnesium metal) found in liquid hydrogen products previously used [6, 7], rather than hydrogen, for which is known not to affect pH. The application of pure hydrogen gas instead of that obtained from a magnesium rod will help to reveal the authentic ergogenic potential of hydrogen. Furthermore, inhalation as a parenteral route of hydrogen administration will enhance the systemic effects of hydrogen, including possible effects on insulin and ghrelin secretion [10].

Drinking hydrogen-rich water appears to alter plasma glucose and insulin levels, an effect likely mediated by increased expression of fibroblast growth factor 21 (FGF21), a metabolic hormone that improves insulin sensitivity and glucose clearance [10]. A possible increased insulin response driven by hydrogen inhalation may promote energy utilization and performance during exercise [12], thus using hydrogen as a stimulator of insulin secretion in a sports setting. Moreover, recent data show that H 2 has therapeutic value for diseases that involve inflammation [ 13 , 14 ], thus increasing the possibility of its use in an athletic environment by counteracting biomarkers of exercise-induced inflammation and damage (e.g. creatine kinase, myoglobin, ferritin, C-reactive protein).

In this randomized controlled preliminary study, we evaluated the effects of 7 days of hydrogen inhalation on exercise performance and serum hormonal and inflammatory profiles in a cohort of young active men and women. Our hypothesis is that hydrogen gas H 2 will improve heart and muscle performance and stimulate insulin secretion, along with reducing the inflammatory response. This appears to be the first clinical study where inhaled hydrogen H 2 has been used to achieve athletic performance.