Study Notes on the Impact of Sodium Bicarbonate on Athletic Performance

Overview

  • The article discusses the impact of Sodium Bicarbonate (NaHCO3) on athletic performance, particularly in relation to exercise duration

  • It is a systematic review conducted by Miralem Hadzic, Max Lennart Eckstein, and Monique Schugardt.

  • Date of publication: 01 June 2019

Abstract

  • Recent literature suggests NaHCO3 is a performance-enhancing aid by reducing acidosis during exercise.

  • Objective: Investigate if exercise duration affects the performance-enhancing effect of NaHCO3.

  • Methodology: 775 studies were identified; 35 randomized controlled trials (RCTs) were included after strict selection based on exercise duration (>4 minutes or ≤4 minutes).

  • Results:

    • 17 studies showed performance-enhancing effects.

    • 11 of 20 studies with <=4 minutes exhibited positive results, while 6 of 15 studies with >4 minutes showed positive results.

  • The influence of exercise duration on the performance effect of NaHCO3 remains unclear due to inconsistencies in results.

Key Terms

  • Sodium Bicarbonate (NaHCO3)

  • Supplementation

  • Acidosis

  • Randomized Controlled Trials (RCTs)

Introduction

  • Bicarbonate (HCO3-) is part of the bicarbonate buffer system crucial for regulating blood pH and metabolic functions.

  • The system helps balance blood pH via proton transfer from carbonic acid (H2CO3).

  • Enhanced buffering via NaHCO3 can lead to increased blood lactate post-exercise, linked with performance effects:

    • HCO3- can influence phosphocreatine degradation and other metabolites which may enhance performance (Siegler et al., 2016).

  • NaHCO3 can improve performance by up to 3% for swimming and cycling (Carr et al., 2011a).

  • However, gastrointestinal (GI) distress has been reported, indicating the possible ergolytic nature of NaHCO3 (Deb et al., 2018).

  • Dosage ranges from 0.2 to 0.4 g/kg body mass could be tolerable (Burke, 2013).

  • Types of studies: Various sports including swimming, cycling, and resistance training have been analyzed concerning NaHCO3 supplementation effects.

Methodology

Literature Search

  • Systematic search on PubMed focusing on studies published from December 2006 to December 2016, updated in July 2018.

  • Only RCTs were included with the following search terms: "sodium bicarbonate" AND "athlete AND performance OR exercise OR recovery".

Eligibility Criteria

  • Included RCTs must:

    • Be single or double-blinded

    • Involve participants identified as athletes

    • Have performance/exercise as a primary outcome

  • Excluded studies: sodium citrate/pyruvate, studies not detailing participant training status.

Data Extraction

  • Extracted data included:

    • Authors, study design, country, subjects' details (age, sex, weight), supplementation specifics (type, dose, ingestion time), performance outcomes, and exercise parameters.

Risk of Bias Assessment

  • Employed Cochrane risk of bias tool to evaluate RCT validity.

  • Each study assessed for selection, performance, detection, attrition, and reporting biases.

Results

  • Initial Findings:

    • Identified 775 studies, filtered down to 35 based on eligibility.

    • Average sample size: 15 athletes (Range: 6-49, Total N=507).

    • Most studies utilized 0.3 g/kg body mass of NaHCO3.

    • Various forms of supplement distribution: Gelatin capsules (21 studies), fluid solutions (12), tablets (2).

Study Characteristics

  • Exercise Task Distribution:

    • Rowing: 5 studies

    • Sport-specific trials: 8 studies (rugby, boxing, etc.)

    • Cycling: 6 studies

    • Swimming: 7 studies

    • Running: 6 studies

    • Upper body tasks and resistance training: respective studies included

Acute vs. Chronic Supplementation

  • Acute Supplementation: 14 trials lasted >4 minutes; 17 trials lasted ≤4 minutes.

  • Chronic supplementation was varied but did include studies demonstrating differing protocols.

Effects of NaHCO3

  • Acute Supplementation for ≤4 Minutes:

    • 9 studies showed enhanced effects from NaHCO3, particularly in swimming and cycling.

    • Other studies showed mixed results or no effect at all.

  • Acute Supplementation for >4 Minutes:

    • 6 studies indicated enhanced performance; notable improvements were occasionally dramatic (e.g., up to 14% improvement).

    • Contrastingly, several did not reveal significant results in performance, indicating varied efficacy dependant on exercise type.

Discussion

  • Although a significant number of studies indicate a positive correlation between NaHCO3 supplementation and performance, inconsistencies continue to challenge the substantiation of this inference.

  • Small sample sizes and differing athlete definitions lead to challenges in reaching a consensus on effective protocols for supplementation.

  • Notability must be given to the contrasting effects of NaHCO3 supplementation at different training capacities, where more trained individuals appear less responsive due to inherent buffering capacities.

Conclusion

  • The influence of exercise duration on NaHCO3 efficacy remains uncertain given inconsistent findings. Further research, particularly focusing on elite athletes, is essential for deriving best practices in NaHCO3 supplementation.

Acknowledgements

  • Research jointly contributed by Hadzic and Eckstein. Acknowledgements were noted for support from Deutsche Forschungsgemeinschaft and the Open Access Publication Fund of the University of Potsdam.

References

  • Citation of numerous studies and articles relevant to sodium bicarbonate supplementation in athletes, highlighting individual studies examining specific sports and conditions.