Blueberry supplementation reduces the blood lactate response to running in normobaric hypoxia but has no effect on performance in recreational runners

Abstract

Background

Blueberries are concentrated with anthocyanins possessing antioxidant properties. As these properties counter fatigue, blueberry supplementation may improve performance and recovery, particularly in hypoxia, where oxidative stress is elevated.

Methods

This study examined the effects of blueberry supplementation on running performance, physiological responses, and recovery in normobaric hypoxia. Eleven experienced runners completed a 30-minute time-trial (TT) in normobaric hypoxia (%O₂ = 15.5 %) on separate days after supplementation with four days of blueberries (BLU) or four days of placebo (PLA). Heart rate (HR), oxygen saturation (SaO₂) and ratings of perceived exertion (RPE) were monitored during the TT. Blood lactate and fraction of exhaled nitric oxide (F_ENO) were assessed pre-TT, post-TT, and during recovery.

Results

No significant differences were observed in the distance run during the TT, HR, SaO₂, and RPE. The post-TT increase in blood lactate was significantly lower in BLU than PLA (p = 0.036). Pre-TT and post-TT F_ENO did not differ between conditions. Blood lactate recovery following the TT was similar between conditions.

Conclusions

Four days of blueberry supplementation did not alter running performance or cardiovascular and perceptual responses in normobaric hypoxia. Supplementation lowered the blood lactate response to running, however, the significance of this finding is uncertain given the absence of an ergogenic effect.

Keywords:

• Polyphenols
• Anthocyanins
• Running
• Endurance
• Altitude
• Nutrition

Authors’ contributions

JPB contributed to the design of the study, to data collection, analysis, and interpretation, as well as to the development of the manuscript. LVG contributed to the design of the study, analysis, and interpretation, as well as to the development of the manuscript. All authors have read and approved the final version of the manuscript.

Funding

This project was supported by a grant from the U.S. Highbush Blueberry Council (USHBC). The USBC was not involved in the design of the study, data collection, data analysis, data interpretation, nor in the writing of the manuscript.

Availability of data and materials

The datasets generated and/or analyzed during the current study are not publicly available but are available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

The study was conducted in accordance with the Declaration of Helsinki and the protocols were approved by the University of the Fraser Valley Human Research Ethics Board.

Consent for publication

All authors approved the final version of the paper.

Competing interests

The authors declare that they have no competing interests.

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