Enhanced 400-m sprint performance in moderately trained participants by a 4-day alkalizing diet: a counterbalanced, randomized controlled trial

Abstract

Background

Sodium bicarbonate (NaHCO₃) is an alkalizing agent and its ingestion is used to improve anaerobic performance. However, the influence of alkalizing nutrients on anaerobic exercise performance remains unclear. Therefore, the present study investigated the influence of an alkalizing versus acidizing diet on 400-m sprint performance, blood lactate, blood gas parameters, and urinary pH in moderately trained adults.

Methods

In a randomized crossover design, eleven recreationally active participants (8 men, 3 women) aged 26.0 ± 1.7 years performed one trial under each individual’s unmodified diet and subsequently two trials following either 4 days of an alkalizing (BASE) or acidizing (ACID) diet. Trials consisted of 400-m runs at intervals of 1 week on a tartan track in a randomized order.

Results

We found a significantly lower 400-m performance time for the BASE trial (65.8 ± 7.2 s) compared with the ACID trial (67.3 ± 7.1 s; p = 0.026). In addition, responses were significantly higher following the BASE diet for blood lactate (BASE: 16.3 ± 2.7; ACID: 14.4 ± 2.1 mmol/L; p = 0.32) and urinary pH (BASE: 7.0 ± 0.7; ACID: 5.5 ± 0.7; p = 0.001).

Conclusions

We conclude that a short-term alkalizing diet may improve 400-m performance time in moderately trained participants. Additionally, we found higher blood lactate concentrations under the alkalizing diet, suggesting an enhanced blood or muscle buffer capacity. Thus, an alkalizing diet may be an easy and natural way to enhance 400-m sprint performance for athletes without the necessity of taking artificial dietary supplements.

Keywords:

• Acid-base balance
• Blood buffer capacity
• Potential renal acid load
• Anaerobic exercise performance

Acknowledgments

We are grateful to all participants for participating in this study. We thank our laboratory staff, Michaela Rau, for contributions and support. We also thank Joel Anderson, PhD, for editing a draft of this manuscript.

Funding

We acknowledge support by the DFG Open Access Publication Funds of the Ruhr-University Bochum.

Availability of data and materials

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

Authors’ contributions

ML and PP conception and design of research; ML and PP performed experiments; ML and ADE analyzed data; ML, ADE, and PP interpreted results of experiments; ML and ADE prepared figures; ML and ADE drafted manuscript; ML and PP edited and revised manuscript; ML, ADE, and PP approved final version of manuscript.

Ethics approval and consent to participate

This study was conducted in accordance with the Declaration of Helsinki, and the protocol was approved by the ethical committee of the Ruhr-University Bochum. All participants gave written informed consent prior to being enrolled in the study.

Competing interests

The authors declare that they have no competing interests.

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