Int J Sports Med 2008; 29(4): 289-293
DOI: 10.1055/s-2007-965363
Physiology & Biochemistry

© Georg Thieme Verlag KG Stuttgart · New York

Acute Resistance Exercise Reduces Heart Rate Complexity and Increases QTc Interval

K. S. Heffernan1 , J. J. Sosnoff2 , S. Y. Jae1 , G. J. Gates3 , B. Fernhall4
  • 1Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Champaign, IL, United States
  • 2Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL, United States
  • 3Center for Chest Disease, Columbia University Medical Center, New York, NY, United States
  • 4College of Applied Health Sciences, University of Illinois at Urbana-Champaign, Champaign, IL, United States
Further Information

Publication History

accepted after revision March 27, 2007

Publication Date:
13 September 2007 (online)

Abstract

Acute resistance exercise (RE) has been shown to reduce cardiac vagal control. Whether this would in turn affect QTc interval (an index of ventricular depolarization/repolarization) or heart rate complexity is not known. Heart rate variability (HRV), heart rate complexity (SampEn), and QT interval (rate corrected using Bazett, Fridericia, Hodges, and Framingham) were measured before and 5 min after an acute RE bout in twelve healthy young men. Normalized high frequency power of HRV (an index of cardiac parasympathetic modulation; HFnu), and SampEn were reduced following RE (p < 0.05). Bazett corrected QTc interval increased following RE (p < 0.05). Change in HFnu from rest to recovery was correlated with both change in SampEn (r = 0.51, p < 0.05) and change in QTc interval for each method of correction (r = - 0.67 to - 0.70, p < 0.05). Acute RE reduced HF spectral power of HRV and this was related to both reduced heart rate complexity and increased QTc length. Thus, during recovery from acute RE, there is prolongation of depolarization and repolarization of the ventricles concomitant with reduced cardiac irregularity, and this may be related to a reduction in cardiac vagal control.

References

 Mr.
Kevin Scott Heffernan, MS 

Department of Kinesiology and Community Health
Exercise and Cardiovascular Research Lab
Rehabilitation Education Center
University of Illinois at Urbana-Champaign

1207 S. Oak St.

Champaign, IL 61820

United States

Phone: + 1 21 76 21 89 00

Fax: + 1 21 73 33 04 04

Email: [email protected]