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Published on: May 5, 2022
Acute resistance exercise reduces heart rate complexity and increases QTc interval
K S Heffernan1, J J Sosnoff, S Y Jae
1Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA. kheffer2@uiuc.edu
Acute resistance exercise reduced cardiac vagal control, leading to decreased heart rate complexity and prolonged QTc interval in healthy men. This suggests potential cardiac changes during recovery from exercise.
Area of Science:
- Cardiovascular Physiology
- Exercise Physiology
- Autonomic Nervous System Function
Background:
- Acute resistance exercise (RE) is known to reduce cardiac vagal control.
- The impact of RE on QTc interval and heart rate complexity remains unclear.
Purpose of the Study:
- To investigate the effects of acute RE on QTc interval and heart rate complexity.
- To determine the relationship between cardiac vagal modulation and these cardiac parameters post-RE.
Main Methods:
- Measurements of heart rate variability (HRV), heart rate complexity (SampEn), and corrected QT interval (QTc) before and after an acute RE bout.
- Analysis included normalized high frequency power (HF (nu)) for parasympathetic modulation.
Main Results:
- RE significantly reduced HF (nu) and SampEn, indicating decreased parasympathetic activity and heart rate complexity.
- Bazett corrected QTc interval significantly increased post-RE.
- Changes in HF (nu) correlated with changes in SampEn and QTc interval.
Conclusions:
- Acute RE reduces cardiac vagal control, leading to decreased heart rate complexity and prolonged ventricular depolarization/repolarization (increased QTc).
- These findings highlight potential cardiovascular adjustments during the recovery phase following resistance exercise.
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