Dataset for "Hydrogen-rich water as a performance enhancing aid in national-level finswimmers: A randomized, double-blind, placebo-controlled crossover study"

Brief summary The aim of this randomized, double-blind, placebo-controlled crossover trial is to evaluate the effect of hydrogen-rich water (HRW) consumption on performance, psychological and biochemical outcomes in national-level monofin swimmers. Participants Twelve national-level monofin swimmers (eight females and four males) participated in this trial. The study was approved by the Ethics Committee of the Faculty of Physical Culture at Palacký University Olomouc (reference 11/2023) in accordance with the Declaration of Helsinki. Participants provided written informed consent. Experimental protocol The protocol was registered on ClinicalTrials.gov (NCT05799911). All participants participated in two testing session and receive HRW and placebo in random order. Each testing session included two training sessions in a 25-m indoor swimming pool and a 24-hour monitored recovery. The morning session took place between 9 and 11 AM and included three high-intensity interval sets, each consisting of 4 × 50 m sprints. The afternoon session took place between 5 and 6 PM and included a continuous 400-m time trial swim. The washout period between testing sessions was 7 days. HRW and placebo administration The Aquastamina-R HRW with molecular hydrogen concentration 0.9 ppm and Aquastamina-Placebo water (Nutristamina, Ostrava, Czech Republic) were contained within a 420 ml plastic aluminum package. Participants took HRW or placebo three days before (3 packages per day) and during testing day (6 packages), 15 packages in total. Measured variables Anthropometric measurements were determined using a SOEHNLE 7307 scale (Leifheit, Nassau, Germany) and a BC-418 MA bioimpedance device (Tanita, Tokyo, Japan). Swimming times were measured using handheld stopwatches (Casio HS-80TW-1EF, Casio Computer Co., Tokyo, Japan) in accordance with the rules of competitive finswimming. 50-m sprint time was recorded by three timekeepers and 400-m swim time was recorded by two timekeepers. Blood lactate concentration was determined from a capillary sample using a Lactate Scout+ Analyzer (EKF Diagnostics, Cardiff, United Kingdom). The perceived exertion was recorded using the Borg scale ranging from 1 (no exertion at all) to 10 (maximum exertion) immediately after completing the given swimming interval. The oxidative stress level was assessed based on the protein carbonyl content in plasma. Venous blood was collected from a forearm vein by a healthcare specialist, taken into heparinized vacuum tubes, and centrifuged at 2000 g for 10 min. The protein carbonyl content was measured using the assay kit MAK094 (Merck, Darmstadt, Germany). Absorbance was measured at 375 nm using an Infinite 200 Pro microplate reader (Tecan, Grödig, Austria). The total protein content in the samples was determined using the bicinchoninic acid method (Serva Electrophoresis, Heidelberg, Germany).