The influence of citrus aurantium and caffeine complex versus placebo on the cardiac autonomic response: a double blind crossover design

Abstract

Background

The purpose of this study was to examine the resting cardiac autonomic nervous system’s response to the ingestion of a complex containing Citrus aurantium + Caffeine (CA + C) and its influence on recovery following a high-intensity anaerobic exercise bout in habitual caffeine users.

Methods

Ten physically active males (25.1 ± 3.9 years; weight 78.71 ± 9.53 kg; height 177.2 ± 4.6 cm; body fat 15.5 ± 3.13%) participated in this study, which consisted of two exhaustive exercise protocols in a randomized crossover design. On each visit the participants consumed either a CA + C (100 mg of CA and 100 mg of C) or placebo (dextrose) capsule. After consumption, participants were monitored throughout a 45-min ingestion period, then completed a repeated Wingate protocol, and were then monitored throughout a 45-min recovery period. Cardiac autonomic function (Heart Rate (HR) and Heart Rate Variability (HRV)) and plasma epinephrine (E) and norepinephrine (NE) were taken at four different time points; Ingestion period: baseline (I1), post-ingestion period (I2); Recovery period: immediately post-exercise (R1), post-recovery period (R2). Heart rate variability was assessed in 5-min increments.

Results

A repeated measures ANOVA revealed significant time-dependent increases in HR, sympathetic related markers of HRV, and plasma E and NE at I2 only in the CA + C trial (p < 0.05); however, no meaningful changes in parasympathetic markers of HRV were observed. Participants recovered in a similar time-dependent manner in all markers of HRV and catecholamines following the PLA and CA + C trials.

Conclusion

The consumption of CA + C results in an increase of sympathetic activity during resting conditions without influencing parasympathetic activity. CA + C provides no influence over cardiac autonomic recovery.

Keywords:

• P-synephrine
• Heart rate variability
• Caffeine
• Anaerobic
• Recovery

Brian Kliszczewicz and Emily Bechke contributed equally to this work.

Brian Kliszczewicz and Emily Bechke contributed equally to this work.

Acknowledgements

Not applicable.

Funding

Not Applicable.

Availability of data and materials

The data sets used during the current study are available from the corresponding author upon reasonable request.

Authors’ contributions

BK contributed to study design, data collection (HRV and Biomarker), data analysis, major contribution to the writing of the manuscript. EB contributed to data collection, performed HRV analysis and interpretation, blood assay analysis, conducted literature review, and major contribution to the writing of the manuscript. CW contributed with data collection, assisted with data analysis (Biomarker), and moderate contributions to the editing of the manuscript. PB contributed to study design, data collection, moderate editing of the manuscript. WH significant contribution to data collection, moderate editing of the manuscript. JM contributed to study design, data statistical analysis, and moderate editing of manuscript. CM contributed to the study design, data collection, moderate editing of manuscript, and procurement of funds. All authors read and approved the final manuscript.

Ethics approval and consent to participate

The Institutional Review Board approved all testing procedures and protocols prior to beginning data collection (17–220) Participants read and sign an informed consent prior too participating in this study.

Consent for publication

Not Applicable.

Competing interests

These authors declare that they have no competing interest and have no relation too the supplement or associated companies.

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