Feasibility of Sodium Bicarbonate Ingestion in Artistic Swimming Performances

Purpose: We evaluated the feasibility of individualized sodium bicarbonate (NaHCO₃) supplementation and its physiological effects on simulated artistic swimming duet performance, including blood buffering responses, perceived exertion, gastrointestinal (GI) tolerance, and performance scores. Methods: Seventeen (n = 17) elite adolescent female artistic swimmers completed an initial trial to determine individual time-to-peak blood bicarbonate concentration (Part 1). Subsequently, a subset (n = 7) completed a randomized, double-blind, crossover intervention (Part 2), performing competition duet routines (4 min) after ingesting either 0.3 g/kg NaHCO₃ or a placebo timed to their individual alkalosis peak. Blood gas and lactate samples were taken pre- and post-performance. Performance was scored by blinded FINA adjudicators. GI discomfort was assessed before and after each routine. Results: Peak blood bicarbonate occurred at 52 ± 9 min post-ingestion, with a mean increase of 6.7 ± 1.8 mmol/L (g = 5.03). In Part 2 (n = 7), NaHCO₃ significantly elevated pre- and post-performance pH (7.46 ± 0.02 vs. 7.37 ± 0.01; 7.34 ± 0.02 vs. 7.26 ± 0.03), HCO₃^- (29.5 ± 0.9 vs. 22.4 ± 0.4 mmol/L; 21.5 ± 1.2 vs. 15.7 ± 1.5 mmol/L), and base excess (5.9 ± 0.6 vs. -2.9 ± 0.5 mmol/L; -4.3 ± 0.8 vs. -10.3 ± 1.1 mmol/L) compared to the placebo (all p < 0.05, g = 3.99-14.93). Post-performance lactate was higher (9.3 ± 1.0 vs. 8.4 ± 0.9 mmol/L, g = 0.89), while rating of perceived exertion (RPE) was lower (12.9 ± 0.7 vs. 14.4 ± 0.7, p < 0.05, g = -2.14). Propulsion improved (6.66 ± 0.16 vs. 6.52 ± 0.20, g = 0.85), with no change in execution. Mild gastrointestinal symptoms were transiently elevated with NaHCO₃. Conclusions: Individualized NaHCO₃ dosing is a feasible and effective ergogenic strategy for artistic swimmers, enhancing systemic alkalosis and perceptual tolerance while preserving technical execution. These findings support the sport-specific integration of NaHCO₃ to optimize anaerobic performance elements in high-level artistic swimming.