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.