The relationship between resting heart rate variability and heart rate recovery.
OBJECTIVE
There is limited research available regarding a possible relationship between resting heart rate variability (HRV) and post-exercise heart rate recovery (HRR). The aim of this study was to examine the relationship between resting HRV and HRR after maximal exercise.


METHODS
Sixty-six college age men participated in this study. HRV was measured in a supine position before and for 30 min after a maximal exercise test on a treadmill. HRV was assessed in the time (i.e., SDNN) and frequency (i.e., normalized HF power [HFnu] and normalized LF:HF ratio [LFnu:HFnu]) domains. Heart rate was recorded at maximal exercise (MHR), and at 1- (HR1) and 2- (HR2) min of the cool-down recovery period. HRR was determined from the difference between MHR and HR1 (HRR1) and the difference between MHR and HR2 (HRR2).


RESULTS
No significant relationship was found between resting HRV and HRR1 or HRR2. However, SDNN was significantly inversely correlated to MHR (P < 0.05), and HFnu was significantly inversely correlated to MHR (P < 0.01), HR1 (P < 0.01), and HR2 (P < 0.05). Furthermore, MHR accounted for the greatest variation in both SDNN and HFnu (P < 0.05).


CONCLUSIONS
Therefore, the HRV may not be related to the recovery of HR expressed as a slope (i.e., HRR) within 2 min following a maximal exercise test. This is possibly due to a significant inverse relationship between HRV and MHR, HR1 and HR2 post-maximal exercise.
Esco
Michael R
MR
Auburn University Montgomery, P.O. Box 244023, Montgomery, AL, 36124-4023, USA. mesco@aum.edu
Olson
Michele S
MS
Williford
Henry N
HN
Blessing
Daniel L
DL
Shannon
David
D
Grandjean
Peter
P
D004562:Electrocardiography; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D010275:Parasympathetic Nervous System / Q000503:physiopathology; D012146:Rest / Q000502:physiology*; D055815:Young Adult