Molecular hydrogen (H2 ), particularly in the form of hydrogen-rich water (HRW), has gained increasing attention for its potential antioxidative, anti-inflammatory, and ergogenic properties in physically active populations. The aim of this narrative review was to synthesize and critically evaluate current evidence on the physiological effects, recovery mechanisms, and performance outcomes associated with molecular hydrogen supplementation in sport and exercise science. A literature search was con ducted for studies published between 2000 and 2024 using PubMed, Scopus, Web of Science, and Google Scholar. The review included studies investigating the effects of H2 administered via hydrogen-rich water, inhalation, or intravenous infusion on oxidative stress, inflammation, fatigue, and physical performance. Current evidence indicates that molecular hydrogen may at tenuate exercise-induced oxidative stress, reduce inflammatory biomarkers, improve lactate metabolism, and alleviate delayed onset muscle soreness. Hydrogen-rich water appears to confer benefits in both acute and chronic exercise contexts; however, study findings remain heterogeneous. Molecular hydrogen shows potential as a supportive intervention in sports medicine and exercise recovery. Nevertheless, variability in study design, limited sample sizes, and inconsistent performance metrics restrict definitive conclusions. Further well-designed, large-scale randomized controlled trials are needed to establish optimal dosing, administration strategies, and long-term effectiveness.