Effects of three-day serial sodium bicarbonate loading on performance and physiological parameters during a simulated basketball test in female university players

The aim of this study was to investigate the effect of 3-day serial sodium bicarbonate ingestion on repeated sprint and jump performance. Fifteen female university basketball players (23.3±3.4 years; 173.1±5.8 cm; 65.8±6.3 kg; 23.6±4.9% body fat) ingested 0.4 g·kg-1 of body mass of sodium bicarbonate or placebo for 3 days (split in 3 equal daily doses), before completing a simulated basketball exercise. Sprint and circuit times, jump heights, performance decrements and gastrointestinal (GI) side effects were recorded during the test and blood lactate concentration was measured pre- and post-test. Sodium bicarbonate supplementation led to significant decreases in mean sprint times (1.34±0.23 vs. 1.70±0.41 s, p=0.008, 95% CI: -0.54 to -0.10 s) and mean circuit times (30.6±2.0 vs. 31.3±2.0 s, p=0.044) and significantly greater mean jump height (26.8 (range 25.2-34.2) vs. 26.0 (range 25.6-33.6) cm, p=0.013) compared to placebo. Performance decrement was significantly less for sprints with sodium bicarbonate compared to placebo (9.9 (range 3.4-37.0) vs. 24.7 (range 4.1-61.3) %, p=0.013), but not different for jumps (13.1±4.5 vs. 12.5±.3.1%, p=0.321) between conditions. No differences in GI side effects were noted between conditions. Significantly greater post-exercise blood lactate concentrations were measured in the sodium bicarbonate condition compared to the placebo condition (8.2±2.8 vs. 6.6±2.4 mmol.L-1, p=0.010). This study is the first to show that serial loading of sodium bicarbonate is effective for basketball players to improve repeated sprint and jump performance during competition, or withstand greater training load during practice sessions without any GI side effects.