A simplified strategy for the estimation of the exercise ventilatory thresholds

A simplified strategy for the estimation of the exercise ventilatory thresholds

Autor Neder, Jose Alberto Autor UNIFESP Google Scholar
Stein, R. Google Scholar
Instituição Universidade Federal de São Paulo (UNIFESP)
Univ Fed Rio Grande Sul
Resumo Purpose: To analyze the limits of agreement between exercise ventilatory threshold values (VT1 and VT2) estimated from a combination of pulmonary gas exchange and ventilatory variables (cardiopulmonary exercise testing) and those derived from an alternative approach based oil the ventilatory response only (VE. ventilometry). Methods: Forty-two nontrained subjects (24 males, aged 18-48, peak VO2 = 33.1 +/- 8.6 mL(.)min(-1.)kg(-1)) performed a maximum incremental cardiopulmonary exercise testing on all electromagnetically braked cycle ergometer. the participants breathed through a Pilot tube (Cardio(2) System (TM), MGC) and a fixed-resistance ventilometer (Micromed, Brazil), which were connected in series. HR values at the estimated VT (VTHR1 and VTHR2) were obtained by the conventional method (ventilatory equivalents. end-expiratory pressures for O-2 and CO2 and the V-slope procedure) and an experimental approach (VE vs time, VE/time vs time. and breathing frequency vs time). Results: There were no significant between-method differences on VTHR1, VTHR2, VTVE1, VTVE2, and peak VE (P > 0.05). After certification of data normality, a Bland-Altman analysis revealed that the mean bias 95% confidence interval of the between-method differences were lower for VTHR2 than VTHR1 (2 +/- 9 and 0 +/- 17 bpm, respectively). VTHR2 according to ventilometry differed more than 10 bpm from the standard procedure in 3 out of 42 subjects (9%). Between-method differences were independent of the level of fitness, as estimated from peak VO2 (P > 0.05). Conclusions: A simplified approach, based oil the ventilatory response as a function of time, call provide acceptable estimates of the exercise ventilatory thresholds-especially VT2-during ramp-incremental cycle ergometry. This new strategy might prove to be useful for exercise training prescription in nontrained adults.
Assunto gas exchange
cardiopulmonary exercise testing
limits of agreement
Idioma Inglês
Data 2006-05-01
Publicado em Medicine and Science in Sports and Exercise. Philadelphia: Lippincott Williams & Wilkins, v. 38, n. 5, p. 1007-1013, 2006.
ISSN 0195-9131 (Sherpa/Romeo, fator de impacto)
Editor Lippincott Williams & Wilkins
Extensão 1007-1013
Fonte http://dx.doi.org/10.1249/01.mss.0000218141.90442.6c
Direito de acesso Acesso aberto Open Access
Tipo Artigo
Web of Science WOS:000237495500027
URI http://repositorio.unifesp.br/handle/11600/28870

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