Author: Agustín Manresa-Rocamora1,2, José Manuel Sarabia1,2, Alejandro Javaloyes1, Andrew A Flatt3, Manuel Moya-Ramón1,2
Affiliation: <sup>1</sup> Sports Research Centre, Department of Sport Sciences, Miguel Hernández University of Elche, 03202 Elche, Spain.
<sup>2</sup> Institute for Health and Biomedical Research (ISABIAL Foundation), Miguel Hernandez University, 03550 Alicante, Spain.
<sup>3</sup> Department of Health Sciences and Kinesiology, Georgia Southern University (Armstrong Campus), Savannah, GA 31419, USA.
Conference/Journal: Int J Environ Res Public Health
Date published: 2021 Sep 29
Other:
Volume ID: 18 , Issue ID: 19 , Pages: 10299 , Special Notes: doi: 10.3390/ijerph181910299. , Word Count: 257
Purpose:
This systematic review with meta-analysis was conducted to establish whether heart rate variability (HRV)-guided training enhances cardiac-vagal modulation, aerobic fitness, or endurance performance to a greater extent than predefined training while accounting for methodological factors.
Methods:
We searched Web of Science Core Collection, Pubmed, and Embase databases up to October 2020. A random-effects model of standardized mean difference (SMD) was estimated for each outcome measure. Chi-square and the I2 index were used to evaluate the degree of homogeneity.
Results:
Accounting for methodological factors, HRV-guided training was superior for enhancing vagal-related HRV indices (SMD+ = 0.50 (95% confidence interval (CI) = 0.09, 0.91)), but not resting HR (SMD+ = 0.04 (95% CI = -0.34, 0.43)). Consistently small but non-significant (p > 0.05) SMDs in favor of HRV-guided training were observed for enhancing maximal aerobic capacity (SMD+ = 0.20 (95% CI = -0.07, 0.47)), aerobic capacity at second ventilatory threshold (SMD+ = 0.26 (95% CI = -0.05, 0.57)), and endurance performance (SMD+ = 0.20 (95% CI = -0.09, 0.48)), versus predefined training. No heterogeneity was found for any of the analyzed aerobic fitness and endurance performance outcomes.
Conclusion:
Best methodological practices pertaining to HRV index selection, recording position, and approaches for establishing baseline reference values and daily changes (i.e., fixed or rolling HRV averages) require further study. HRV-guided training may be more effective than predefined training for maintaining and improving vagal-mediated HRV, with less likelihood of negative responses. However, if HRV-guided training is superior to predefined training for producing group-level improvements in fitness and performance, current data suggest it is only by a small margin.
Keywords: autonomic nervous system; cardiorespiratory fitness; heart rate recovery; parasympathetic activity; resting heart rate.
PMID: 34639599 PMCID: PMC8507742 DOI: 10.3390/ijerph181910299