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

Abstract

of reply HRV in an incremental effort test: analysis time-frequency. Fit Perf J. 2007;6(3):181-7. ABSTRACT: Introduction: This study describes the behavior of the cardiac rhythm variability (CRV) in the frequency domain, during the accomplishment of an incremental test until the exhaustion point, with the use of the Fourier Fast Transform (FFT) andauto-regressive models (AR). The Wavelet is the time-frequency methodology more useful in the CRV analysis; this will be used to explain in details the CRV kinetic in an incremental workload. Materials and methods: There had been used 8 males track bikers (age 17.12 ± 1.11 years), through an effort test in an ergonometric cycle of electromagnetic brake, with scale of 25W 1000W and minimum increments of 1W/s. The Wavelet Transform was adopted by being the most powerful tool for the accomplishment of a time-frequency analysis of a not-stationary secular series, as the cardiac frequency, after having been treated for the methods detrending, softness and fi ltering. Discussion: The analyses had been made in three zones of effort: zone 1 (Z-1), with frequencies below 150 beats for minute (bpm), zone 2 (Z-2), with frequencies below 185 bpm and zone 3 (Z-3), above of these values.

Wavelet Transforms in Sport: Application to Biological Time Series

“…Nevertheless, here we propose the DWT method to remove extremely slowly oscillating components from HRV data, considering that it provides greater control of the content in low frequency to be removed, and it is important to understand the effect of detrending on the spectral properties of the time series. DWT was used to decompose the HRV signal into J wavelet scales, with Daubechies (Db8) wavelet filters (García-Manso et al, 2007). Then, the detrended signal is reconstructed using the wavelet coefficients at the first J-1 scales.…”