Dose-dependent effects of sodium bicarbonate supplementation combined with sprint interval training on performance...

Sprint interval training (SIT) effectively improves physical performance in team-sport athletes, while sodium bicarbonate (Sb) supplementation may enhance training adaptations. However, the dose-dependent effects of Sb during SIT remain unclear in basketball players. Therefore, this study examined the effects of two Sb doses combined with SIT on physical performance adaptations in basketball players.

Forty trained male basketball players (age: 21.6 ± 2.0 years, height: 185.4 ± 3.5 cm, body mass: 84.1 ± 4.4 kg) were recruited and randomly assigned to four groups: SIT + 0.3 g·kg^-1 Sb (n = 10), SIT + 0.45 g·kg^-1 Sb (n = 10), SIT + placebo (PL) (n = 10), and control (CON) (n = 10). The intervention lasted four weeks during the preparatory phase of the season. Participants in the training groups performed SIT three times per week in addition to their regular basketball training. The SIT protocol consisted of four sets of ten 5-second maximal sprints, with 20 seconds of active recovery between repetitions and 2 minutes of rest between sets. All 40 enrolled participants successfully completed the 4-week intervention, resulting in a 0% dropout rate. Performance assessments conducted before and after the intervention included countermovement vertical jump (CMVJ), standing long jump (SLJ), 20 m sprint, Illinois change-of-direction speed (CODS), Yo-Yo Intermittent Recovery Test Level 1 (Yo-Yo IR1), and Wingate anaerobic power (peak power output [PPO] and mean power output [MPO]).

All training groups showed significant improvements in physical performance variables over time (p < 0.05). Significant group by time interaction effects were observed for all performance variables (p ≤ 0.001), indicating that the SIT groups showed more gains compared with the CON group. Both Sb supplementation groups demonstrated greater improvements than the SIT + PL group in CMVJ, SLJ, sprint performance, CODS, Yo-Yo IR1 distance, PPO, and MPO (p < 0.05). Furthermore, the SIT + 0.45 g·kg^-1 Sb group exhibited significantly greater performance enhancements than the SIT + 0.3 g·kg^-1 Sb group across all measured variables.

Four weeks of SIT improved performance in trained basketball players, with Sb supplementation providing additional dose-dependent benefits (0.45 > 0.3 g⋅kg^-1). While the higher dose yielded superior adaptations, its practical application should be balanced against potential gastrointestinal discomfort and individual tolerance to ensure long-term athlete compliance.