Heart rate variability during high‐intensity field exercise in female distance runners

Abstract

The purposes of this study were to demonstrate the transition of heart rate variability (HRV) during trials in the field and to examine the relationship between peak frequency of high-frequency band (HF) and stride frequency. Ten healthy long-distance college female runners (age 19-21 years) performed a 3000 m realistic time trial. The time-series power spectrum analysis by maximum entropy method was used to evaluate cardiac autonomic nervous activity during the race. Cross-correlation coefficients were calculated to estimate the degree of linear co-ordination between the central peak frequency of HF and stride frequency. Just after starting, the decrease in HF (0.15-1.00 Hz) and a transient increase of low-frequency band (LF)/HF were found. After that, the HF remained at a low level and LF/HF decreased sharply. These findings suggested that the parasympathetic activity was suppressed and sympathetic activity increased just after starting, and the sympathetic activity reached the saturated level according to continuation of high-intensity exercise. In spite of the significant decrease of HRV during trials, peak frequency of HF could be differentiated clearly. The cross-correlation coefficient of peak frequency of HF and stride frequency was from 0.703 to 0.868. This finding indicated that exercise rhythm reflected HRV during high-intensity running in the field.

Real‐Time Analysis of the Heart Rate Variability During Incremental Exercise for the Detection of the Ventilatory Threshold

“…On the other hand, the MEM does not depend on stationary data . It enables the assessment of the HRV based on an analysis of short‐term RR intervals .…”

“…On the other hand, the MEM does not depend on stationary data . It enables the assessment of the HRV based on an analysis of short‐term RR intervals . As the lower threshold of the LF component on the HRV analysis using the MEM is 0.04 Hz, the time length of the shortest time‐series data required for the assessment of the LF component is ≈25 seconds.…”

Cardiac Autonomic Control Immediately after Exercise in Female Distance Runners

“…The upper limit of the frequency range was altered by respiratory frequency because HF power was influenced by respiratory activity (Hirsh and Bishop, 1981). During high-intensity exercise, the central frequency responded to respiratory frequency even if total power was low (Sumi et al, 2006). In this study, we considered that total power immediately after exercise was as low as that during exercise and confirmed the central frequency in the power spectrum.…”

“…Since conventional methods, such as the fast Fourier transform (FFT) and autoregressive (AR) techniques, need stationary data, they cannot be applied to the duration of sharp change in HR immediately after exercise (Goldberger et al, 2006). Recently, newer methods, such as the maximum entropy method (Macor et al, 1996;Murasato et al, 1998;Sumi et al, 2006) and the complex demodulation method (Hayano et al, 1994), which do not depend on stationary data, have been developed. These newer methods make it possible to assess autonomic nervous activity based on a short-term R-R interval.…”

Analysis of reply HRV in a incremental effort test: analysis time-frequency

“…At rest, HF is used as an index of cardiac parasympathetic nervous activity and also refl ects the respiratory sinus arrhythmia (RSA), is synchronizing with the changes of volumes respiratory and respiratory frequency 25,26,27,28,29,30 . The relationship between BF and HF falls as the BF increases and is greater when the volumes of air breathed increase 25 .…”