A systematic literature review of the effects of molecular hydrogen during exercise

Abstract

In the last decade, use of molecular hydrogen, through hydrogen-rich water (HRW), has become commonplace in the sports industry with anecdotal claims of improving athletic performance and endurance. Publications, clinical trials, and case studies have begun to emerge with the growing interest to clinically-validate the claims of improved performance and recovery in the athletic population. The objective of the current article is to review the recent literature to understand the effects of molecular hydrogen, through ingestion of hydrogen-rich water on muscles, joints, and athletic performance during the peri-exercise period. The following literature review documents the relevant effects identified within the included studies. A review of the studies published in the last ten years (2012-2022) pertaining to hydrogen-rich water (HRW) was performed. Using the PubMed search engine, the terms “hydrogen water” and “athlete” were searched. Quantitative data points pertaining to cardiorespiratory variables, blood markers, subject reported outcome measures, and athletic performance were identified from the included studies. Based on the aforementioned search criteria, one hundred and one articles were identified. Among these, fourteen studies pertained to the effects of molecular hydrogen during exercise. Of these studies, eleven studies reported the clinical findings associated with oral ingestion of liquid HRW and three studies identified observations pertaining to other hydrogen-rich applications in transdermal and tablet forms. The recent literature suggests that HRW may provide anti-inflammatory benefits as a neutralizing agent without evidence of side effects during high-intensity exercise in trained athletes. Consequently, when used during the peri-exercise period, HRW may be associated with anti-fatigue effects and improved athletic performance. The identified evidence supporting the use of HRW during the peri-exercise period is limited, and its extrapolation should be performed with caution. Despite the lack of significant high-quality evidence available in the recent literature, molecular hydrogen, through ingestion of HRW, has been adopted in the sports industry for its antioxidant, anti-inflammatory, and anti-fatigue properties identified in trained athletes, and it is used anecdotally to impact athletic performance without significant observed risk of side effects.