Background. Alkaline water often above pH 7 with a defined mineral profile is introduced to athletes as a means of hydration and recovery. The claims include increases in acid–base balance, the markers of hydration and performance. However, empirical evidence is mixed. Aim. To integrate the human evidence around the effects of alkaline water intake on hydration status, acid–base balance and athletic performance, and to contextualize the claims against sports nutrition protocols. Material and methods. A review of the literature was conducted to search for studies related to impacts of alkaline water on hydration, acid–base balance, and exercise performance. The search of the databases PubMed, Scopus, and Google Scholar was conducted for papers published between 2010 and 2025 with the following words: “alkaline water”, “electrolyzed water”, “hydration”, “acid–base balance”, “exercise”, “athletes”, and “performance”. Only human interventional or controlled studies were included. Results. Consistently, alkaline water elevated urine pH and reduced urine specific gravity, sometimes decreasing blood viscosity upon rehydration 1. However, results for systemic hydration markers (e.g., plasma osmolality, body mass restoration) were varied 1–4,7,8,10. Only minor, inconsistent improvements were noted in acid–base markers (e.g., bicarbonate) and certain anaerobic performance metrics; these gains were limited to small, short-term trials 1,2,7. Many studies found no performance advantage over neutral water or standard sports drinks 4,8,10. Conclusions. Alkaline water is safe and consistently induces urinary alkalinization and modulates acid–base markers. However, its superiority over traditional hydration practices remains unproven. Future research requires well-powered, blinded RCTs with standardized water composition and athletic outcomes. Practical guidance should view alkaline water as an optional preference, not a replacement, for established hydration protocols 6.
Słyś et al. (Sun,) studied this question.