Int J Sports Med 2010; 31(10): 698-703
DOI: 10.1055/s-0030-1255110
Training & Testing

© Georg Thieme Verlag KG Stuttgart · New York

A Simple Approach to Assess VT During a Field Walk Test

V. Z. Dourado1 , M. C. Banov2 , M. C. Marino1 , V. L. de Souza1 , L. C. de O. Antunes2 , M. A. McBurnie3
  • 1Federal University of São Paulo, Department of Health Sciences, Santos, Brazil
  • 2Botucatu Medical School, São Paulo State University (UNESP), Rehabilitation Department, Botucatu, Brazil
  • 3Kaiser Permanente Center for Health Research, Center for Health Research, Portland, United States
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Publikationsverlauf

accepted after revision May 20, 2010

Publikationsdatum:
08. Juli 2010 (online)

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Abstract

We aimed to examine whether the ventilatory threshold (VT) during an incremental shuttle walk test (ISWT) could be determined using heart rate variability (HRV) analysis. Further aims were to assess variables capable of predicting performance in the ISWT and the intensity of this test. Beat-to-beat RR intervals and gas exchange values in 10 healthy subjects (31–83 years; 7 men) were collected during the ISWT. The ventilatory equivalent was used to assess VT from respiratory components. To determine the HRV threshold (HRVT), the instantaneous beat-to-beat variability values of the RR intervals at each stage of exercise were graphically plotted against walking speed (WS). The oxygen consumption at HRVT was calculated (VO2HRVT). No significant differences were found between walking speed (WS) at VT and WS at HRVT (5.04±1.00 vs. 5.10±1.04 km/h; p=0.89). Linear regression analysis revealed a strong correlation between VO2VT and VO2HRVT (r2=0.896). The Bland and Altman plot analysis revealed an agreement between VO2VT and VO2HRVT (−0.05; 95%CI: −0.30–0.20 L/min). Thus, the VT can be assessed during the ISWT using a simple heart monitor. The ISWT may be a useful tool to assess exercise capacity and prescribe walking programs.

References

Correspondence

Prof. Victor Zuniga DouradoPT, PhD 

Federal University of São Paulo

Department of Health Sciences

AV. Ana Costa, 95

11060-001 Santos

Brazil

Telefon: +55/13/3232 2569

Fax: +55/13/3232 2569

eMail: vzdourado@yahoo.com.br