Comparison of anaerobic threshold determined by visual and mathematical methods in healthy women

Abstract

Several methods are used to estimate anaerobic threshold (AT) during exercise. The aim of the present study was to compare AT obtained by a graphic visual method for the estimate of ventilatory and metabolic variables (gold standard), to a bi-segmental linear regression mathematical model of Hinkley's algorithm applied to heart rate (HR) and carbon dioxide output (V . CO 2 ) data. Thirteen young (24 ± 2.63 years old) and 16 postmenopausal (57 ± 4.79 years old) healthy and sedentary women were submitted to a continuous ergospirometric incremental test on an electromagnetic braking cycloergometer with 10 to 20 W/min increases until physical exhaustion. The ventilatory variables were recorded breath-to-breath and HR was obtained beat-tobeat over real time. Data were analyzed by the nonparametric Friedman test and Spearman correlation test with the level of significance set at 5%. Power output (W), HR (bpm), oxygen uptake (V . . CO 2 and HR was adequate and promising for AT detection in young and middle-aged women, representing a semiautomatic, non-invasive and objective AT measurement.O

Precisão da medida do limiar anaeróbio por meio do calorímetro portátil

“…calculations have been helping in the automatization and/ or semi-automatization of this procedure [9][10][11][12] .…”

Ratings of perceived exertion at anaerobic threshold in patients with coronary artery disease

“…This method was based on the V-Slope method described by Beaver et al 17 . The VAT was considered as the average of the data obtained from the analyses of the three observers 16,17 .…”

Reprodutibilidade da determinação do limiar anaeróbico em pacientes com insuficiência cardíaca

“…In both methods, the AT was assessed in charts with eight-breath moving average 15 . In the visual-graphic method, AT was defined as the point at which there was a break in the linearity of the response of VCO 2 compared to VO 2 , as a function of time 15 ; and in the V-slope method, AT was determined as the point from which there was a change in the slope of the curve 1,5,[12][13][14] . To evaluate reproducibility, three investigators with prior training in both methods determined the AT independently.…”

“…Therefore, there is a ventilatory threshold coincident with the AT 13,14 , which is detected by gas analysis using spirometry. 15 Both VO 2peak and AT determined by the ventilatory method are considered valid and reproducible in healthy subjects 1,5,14,16 . However, as the determination of maximum stress can be subjective in individuals with HF 1,16 , AT can be an alternative option comparable to the VO 2peak to predict aerobic performance 1,8,13,[16][17][18] .…”