The effects of a novel bicarbonate loading protocol on serum bicarbonate concentration: a randomized controlled trial

Abstract

Background

Previous studies have shown that sodium bicarbonate ingestion may enhance intense exercise performance, but may also cause severe gastrointestinal distress. The purpose of this study was to determine whether a modified sodium bicarbonate (SB) ingestion protocol would elevate serum bicarbonate concentration more than previous methods without causing gastrointestinal distress.

Methods

In randomized order, seven (5 men, 2 women) elite middle-distance runners ingested either placebo, Modified SB (600 mg·kg^− 1 over 19.5 h), or Acute SB (300 mg·kg^− 1) in opaque gelatin capsules. Baseline and post-ingestion blood samples were analyzed for bicarbonate, pH, sodium, hematocrit, and lactate. Repeated measures ANOVA (2 time points × 3 conditions) were analyzed to determine differences in serum bicarbonate, lactate, sodium, blood pH, and hematocrit. Gastrointestinal distress was assessed via self-report on a Likert scale of 1–10. Simple (condition) and repeated (time) within-participant contrasts were used to determine the location of any statistically significant main and interaction effects (p ≤ 0.05).

Results

Both Modified SB (7.6 mmol·L^− 1, p < 0.01) and Acute SB (5.8 mmol·L^− 1, p < 0.01) increased serum bicarbonate concentration compared to the placebo (p ≤ 0.05). Post-ingestion serum bicarbonate concentration was significantly higher for the Modified SB (34.7 ± 2.2 mmol·L^− 1, 28.0% increase) trials than the Acute SB (33.5 ± 2.0 mmol·L^− 1, 20.9% increase) trials (p = 0.05). There was no reported severe GI distress in the Modified SB trials, but two cases in the Acute SB trials.

Conclusions

Modified SB elevated serum bicarbonate concentration more than Acute SB, without any severe gastrointestinal side effects. Consequently, it is recommended that future experimentation involving SB by researchers and athletes use the novel ingestion protocol described in this study due to its potential for improved effectiveness and reduced gastrointestinal impact.

Trial registration

ClinicalTrials.gov , NCT03813329 . Registered 23 January 2019 - Retrospectively registered,

Keywords:

• Ergogenic
• Running
• Elite
• Bicarbonate
• Lactate
• Buffer
• Nutrition
• Supplement

Acknowledgements

The authors would like to acknowledge the commitment and effort of all the athletes who participated in this study.

Authors’ contributions

AM completed the data analysis, manuscript writing, and revision. AR was involved in all aspects of the study design, data collection, data analysis, and manuscript preparation. AC contributed to the design of the study, randomization of the participants and manuscript preparation. SAH contributed to the study design and development of data collection. NK contributed to the study design, IRB submission, participant recruitment, data collection, and manuscript preparation. All authors read and approved the final manuscript.

Funding

There was no funding for this study.

Availability of data and materials

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.

Ethics approval and consent to participate

The methods and procedures of the present study were approved by an the California State University Los Angeles Institutional Review Board (IRB) and were performed in accordance with the ethical standards from the 1964 Declaration of Helsinki. All participants provided IRB-approved written informed consent prior to study initiation.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

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