Effects of Sodium Bicarbonate, Caffeine, and Their Combination on Repeated 200-m Freestyle Performance

Abstract

The purpose of this study was to investigate the effects of sodium bicarbonate (NaHCO(3)), caffeine, and their combination on repeated 200-m freestyle performance. Six elite male freestyle swimmers ingested NaHCO(3) (0.3 g/kg; B), caffeine (6.2 +/- 0.3 mg/kg; C), a combination of both (B+C), and placebo (P) on 4 separate occasions before completing 2 maximal 200-m freestyle time trials (TT1 and TT2) separated by 30 min. No significant differences (p = .06) were observed for performance in TT1 (B 2:03.01 +/- 0:03.68 min, C 2:02.42 +/- 0:03.17 min, B+C 2:01.69 +/- 0:03.19 min, P 2:03.77 +/- 0:03.21 min) or TT2 (B 2:02.62 +/- 0:04.16 min, C 2:03.90 +/- 0:03.58 min, B+C 2:01.70 +/- 0:02.84 min, P 2:04.22 +/- 0:03.75 min). The drop-off in performance time from TT1 to TT2, however, was significantly greater when C was ingested than with B (-1.5%, p = .002) or B+C (-1.2%, p = .024). This is likely because of the lower blood pH and slower recovery of blood HCO(3) post-TT1 after C ingestion. These findings suggest that the ergogenic benefit of taking C alone for repeated 200-m swimming performance appears limited. When combined with NaHCO(3), however, its negative impact on repeated maximal exercise performance is reversed.

Evaluating the effects of caffeine and sodium bicarbonate, ingested individually or in combination, and a taste-matched placebo on high-intensity cycling capacity in healthy males

“…Additionally there were differences in approaches to abstinence of caffeine intake prior to exercise, an area recognised to limit the ability to compare studies evaluating the ergogenic effects of caffeine (Tallis et al 2015). For example, participants in Carr et al (2011) and Pruscino et al (2008) abstained for 48 hours prior to exercise whereas participants in Kilding et al (2012) abstained for the duration of the study. Participants in Christensen et al (2014) were asked to avoid caffeine drinks 36 hours prior to testing.…”

“…When considering the between treatment coefficient of variation for mean performance time was 0.4%, it is plausible that these GI issues might have modulated the potential ergogenicity of NaHCO3. Pruscino et al (2008) reported that caffeine alone negatively impacted repeated 200 m freestyle swimming performance compared with all treatments (range: -1.5 to -0.9%). Performance was significantly slower with caffeine compared to NaHCO3 (-1.5±0.7%) and NaHCO3 and caffeine combined (-1.2±1.0%).…”

“…With caffeine and NaHCO3 eliciting performance enhancing effects by different mechanisms, a synergistic effect may occur resulting in substantial performance gains. However, to the best of our knowledge only four studies have evaluated the effects of combining caffeine and NaHCO3 on exercise performance in vivo (Carr et al 2011;Christensen et al 2014;Kilding et al 2012;Pruscino et al 2008). Carr et al (2011) reported that compared with placebo (PLA) 6 mg.kg -1 body mass caffeine improved power output in elite males during 2000-m rowing by 2.3%.…”

“…For example, although each study adopted a dosage of 5 0.3 g.kg -1 NaHCO3, the dosage of caffeine varied between studies with Pruscino et al (2008) and Carr et al (2011) adopting ~6 mg.kg -1 whereas Kilding et al (2012) and Christensen et al (2014) adopted 3 mg.kg -1 . Additionally there were differences in approaches to abstinence of caffeine intake prior to exercise, an area recognised to limit the ability to compare studies evaluating the ergogenic effects of caffeine (Tallis et al 2015).…”

Sodium bicarbonate ingestion and individual variability in time-to-peak pH

“…Indeed, such is the wealth of published studies on sodium bicarbonate, that recently, researchers have started to focus on its co-ingestion with other active ingredients such as caffeine 24,25 and -alanine 26,27,28 in order to assess the potential additive effects in order to provide further performance enhancements via the activation of different ergogenic mechanisms simultaneously.…”