Author: Benjamim CJR1,2, Kliszczewicz B3, Garner DM4, Cavalcante TCF1, da Silva AAM1, Santana MDR2, Valenti VE5
Affiliation: <sup>1</sup>Development, Nutrition, Phytotherapy and Hygiene Research Group, University of Pernambuco, Petrolina, PE, Brazil.
<sup>2</sup>Physiological and Collective Sciences Nucleus, School of Juazeiro do Norte, Juazeiro do Norte, CE, Brazil.
<sup>3</sup>Department of Exercise Science and Sport Management, Kennesaw State University, Kennesaw, GA, USA.
<sup>4</sup>Cardiorespiratory Research Group, Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, OX3 0BP, United Kingdom.
<sup>5</sup>Center for the Study of the Autonomic Nervous System (CESNA), UNESP, Marilia, SP, Brazil.
Conference/Journal: J Am Coll Nutr.
Date published: 2019 Dec 20
Other:
Volume ID: 1-11 , Special Notes: doi: 10.1080/07315724.2019.1705201. [Epub ahead of print] , Word Count: 283
Evaluating different doses of caffeine (CAF) on heart rate (HR) variability (HRV) during and following exercise in order to assess its impact on autonomic control. We intended to evaluate the influence of CAF as a supplement before exercise on HRV through a systematic review. Manuscripts were selected based on electronic searches of MEDLINE, EMBASE and CINAHL databases from 2010 to 2019 and followed the protocol Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA). Blind randomized designs and controlled trials that reported the influence of CAF on HRV during exercise and during recovery from exercise, with strength of evidence assessed using the GRADE system; the search for the studies was organized using the PICOS strategy. A total of 1797 articles were recognized, following the screening and eligibility stages, 9 studies continued to the final sample. Six studies reported that the combination of CAF supplementation with physical exercise exhibited higher HR when compared to the placebo group during post-exercise recovery; additionally, prolonged activation of sympathetic cardiac control and delayed parasympathetic reactivation following exercise was observed. However, three studies demonstrated no CAF influence when using similar doses. This review observed equivocal results in HR and HRV recovery following exercise with the presence of CAF consumption. These findings cannot confirm the cardiac autonomic changes observed where entirely due to the influence of CAF, and further studies should be performed to better understand this relationship.KEY TEACHING POINTSCAF increased HR during exercise and throughout the recovery period.CAF prolonged post exercise sympathetic activity.CAF delayed vagal reactivation.Deviations in HRV and HR are dependent on the combination of three main factors: CAF dosage, type of exercise, and cardiorespiratory fitness.
KEYWORDS: Autonomic nervous system; Caffeine; cardiovascular physiology; cardiovascular system; exercise
PMID: 31860391 DOI: 10.1080/07315724.2019.1705201