Int J Sports Med 2006; 27(12): 959-967
DOI: 10.1055/s-2006-923849
Physiology & Biochemistry

© Georg Thieme Verlag KG Stuttgart · New York

Assessment of Ventilatory Thresholds from Heart Rate Variability in Well-Trained Subjects during Cycling

F. Cottin1 , P.-M. Leprêtre1 , P. Lopes1 , Y. Papelier3 , C. Médigue2 , V. Billat1
  • 1Laboratory of Exercise Physiology (LEPH), University of Evry, E. A. 3872 Genopole, Evry Cedex, France
  • 2French National Institute for Research in Computer Science and Control (INRIA), Le Chesnay, France
  • 3Laboratory of Physiology, Medicine Faculty, University of Paris XI, E. F. R., Hôpital Antoine Béclère, Clamart Cedex, France
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Publikationsverlauf

Accepted after revision: December 5, 2005

Publikationsdatum:
17. August 2006 (online)

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Abstract

The purpose of this study was to implement a new method for assessing the ventilatory thresholds from heart rate variability (HRV) analysis. ECG, V·O2, V·CO2, and V·E were collected from eleven well-trained subjects during an incremental exhaustive test performed on a cycle ergometer. The “Short-Term Fourier Transform” analysis was applied to RR time series to compute the high frequency HRV energy (HF, frequency range: 0.15 - 2 Hz) and HF frequency peak (f HF) vs. power stages. For all subjects, visual examination of ventilatory equivalents, f HF, and instantaneous HF energy multiplied by f HF (HF · f HF) showed two nonlinear increases. The first nonlinear increase corresponded to the first ventilatory threshold (VT1) and was associated with the first HF threshold (TRSA1 from f HF and HFT1 from HF · f HF detection). The second nonlinear increase represented the second ventilatory threshold (VT2) and was associated with the second HF threshold (TRSA2 from f HF and HFT2 from HF · f HF detection). HFT1 , TRSA1, HFT2, and TRSA2 were, respectively, not significantly different from VT1 (VT1 = 219 ± 45 vs. HFT1 = 220 ± 48 W, p = 0.975; VT1 vs. TRSA1 = 213 ± 56 W, p = 0.662) and VT2 (VT2 = 293 ± 45 vs. HFT2 = 294 ± - 48 W, p = 0.956; vs. TRSA2 = 300 ± 58 W, p = 0.445). In addition, when expressed as a function of power, HFT1, TRSA1, HFT2, and TRSA2 were respectively correlated with VT1 (with HFT1 r² = 0.94, p < 0.001; with TRSA1 r² = 0.48, p < 0.05) and VT2 (with HFT2 r² = 0.97, p < 0.001; with TRSA2 r² = 0.79, p < 0.001). This study confirms that ventilatory thresholds can be determined from RR time series using HRV time-frequency analysis in healthy well-trained subjects. In addition it shows that HF · f HF provides a more reliable and accurate index than f HF alone for this assessment.

References

PhD François Cottin

Department of Sport and Exercise Science
University of Evry

Boulevard F. Mitterrand

91025 Evry Cedex

France

Telefon: + 330169644881

Fax: + 33 01 69 64 48 95

eMail: fcottin@univ-evry.fr