Heart Rate Dynamics During Acute Recovery From Maximal Aerobic Exercise in Young Adults

Nathaniel T Berry; Emily Bechke; Lenka H Shriver; Susan D Calkins; Susan P Keane; Lilly Shanahan; Laurie Wideman

doi:10.3389/fphys.2021.627320

Heart Rate Dynamics During Acute Recovery From Maximal Aerobic Exercise in Young Adults

Front Physiol. 2021 Feb 5:12:627320. doi: 10.3389/fphys.2021.627320. eCollection 2021.

Authors

Nathaniel T Berry¹, Emily Bechke¹, Lenka H Shriver², Susan D Calkins³, Susan P Keane⁴, Lilly Shanahan⁵, Laurie Wideman¹

Affiliations

¹ Department of Kinesiology, The University of North Carolina at Greensboro, Greensboro, NC, United States.
² Department of Nutrition, The University of North Carolina at Greensboro, Greensboro, NC, United States.
³ Department of Human Development and Family Studies, The University of North Carolina at Greensboro, Greensboro, NC, United States.
⁴ Department of Psychology, The University of North Carolina at Greensboro, Greensboro, NC, United States.
⁵ Department of Psychology, University of Zurich, Zurich, Switzerland.

Abstract

Introduction: Resting heart rate (HR_rest), heart rate variability (HRV), and HR recovery (HRR) from exercise provide valuable information about cardiac autonomic control. RR-intervals during acute recovery from exercise (RR_rec) are commonly excluded from HRV analyses due to issues of non-stationarity. However, the variability and complexity within these trends may provide valuable information about changes in HR dynamics.

Purpose: Assess the complexity of RR_rec and determine what physiologic and demographic information are associated with differences in these indices in young adults.

Methods: RR-intervals were collected throughout maximal treadmill exercise and recovery in young adults (n = 92). The first 5 min of RR_rec were (1) analyzed with previously reported methods that use 3-interval lengths for comparison and (2) detrended using both differencing_(diff) and polynomial regression_(res). The standard deviation of the normal interval (SDNN), root mean square of successive differences (rMSSD), root mean square (RMS) of the residual of regression, and sample entropy (SampEn) were calculated. Repeated measures analysis of covariance (ANCOVA) tested for differences in these indices for each of the methodological approaches, controlling for race, body fat, peak oxygen uptake (VO_2p _eak), and resting HR (HR_rest). Statistical significance was set at p < 0.05.

Results: VO_2p _eak and HR_rest were significantly correlated with traditional measures of HRR and the variability surrounding RR_rec. SampEn_diff and SampEn_res were correlated with VO_2p _eak but not HR_rest or HRR. The residual-method provided a significantly (p = 0.04) lower mean standard error (MSE) (0.064 ± 0.042) compared to the differencing-method (0.100 ± 0.033).

Conclusions: Complexity analysis of RR_rec provides unique information about cardiac autonomic regulation immediately following the cessation of exercise when compared to traditional measures of HRR and both HRrest and VO2peak influence these results.

Keywords: cardiac dynamics; emerging adults; heart rate variability; non-linear dynamics; recovery heart rate; recovery heart rate variability.

Grants and funding

R01 HD078346/HD/NICHD NIH HHS/United States