Anaerobic Threshold by Mathematical Model in Healthy and Post-Myocardial Infarction Men.
The aim of this study was to determine the anaerobic threshold (AT) in a population of healthy and post-myocardial infarction men by applying Hinkley's mathematical method and comparing its performance to the ventilatory visual method. This mathematical model, in lieu of observer-dependent visual determination, can produce more reliable results due to the uniformity of the procedure. 17 middle-aged men (55±3 years) were studied in 2 groups: 9 healthy men (54±2 years); and 8 men with previous myocardial infarction (57±3 years). All subjects underwent an incremental ramp exercise test until physical exhaustion. Breath-by-breath ventilatory variables, heart rate (HR), and vastus lateralis surface electromyography (sEMG) signal were collected throughout the test. Carbon dioxide output (V˙CO2), HR, and sEMG were studied, and the AT determination methods were compared using correlation coefficients and Bland-Altman plots. Parametric statistical tests were applied with significance level set at 5%. No significant differences were found in the HR, sEMG, and ventilatory variables at AT between the different methods, such as the intensity of effort relative to AT. Moreover, important concordance and significant correlations were observed between the methods. We concluded that the mathematical model was suitable for detecting the AT in both healthy and myocardial infarction subjects.
Department of Physical Therapy, Cardiovascular Physical Therapy Laboratory, Nucleus of Research in Physical Exercise, Federal University of Sao Carlos - UFSCar, Sao Carlos, Sao Paulo, Brazil.
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Novais
Department of Physical Therapy, Cardiovascular Physical Therapy Laboratory, Nucleus of Research in Physical Exercise, Federal University of Sao Carlos - UFSCar, Sao Carlos, Sao Paulo, Brazil.
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Silva
Department of Physical Therapy, Cardiovascular Physical Therapy Laboratory, Nucleus of Research in Physical Exercise, Federal University of Sao Carlos - UFSCar, Sao Carlos, Sao Paulo, Brazil.
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Simões
Department of Physical Therapy, Cardiovascular Physical Therapy Laboratory, Nucleus of Research in Physical Exercise, Federal University of Sao Carlos - UFSCar, Sao Carlos, Sao Paulo, Brazil.
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Sakabe
Laboratory of Exercise Physiology, Faculty of Physical Education, Estadual University of Campinas, Campinas, Sao Paulo, Brazil.
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Martins
Department of Physical Therapy, Cardiovascular Physical Therapy Laboratory, Nucleus of Research in Physical Exercise, Federal University of Sao Carlos - UFSCar, Sao Carlos, Sao Paulo, Brazil.
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Oliveira
Department of Statistics, Federal University of Sao Carlos, Sao Carlos, Sao Paulo, Brazil.
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Diniz
Department of Clinical Medicine, Laboratory of Exercise Physiology, Division of Cardiology, Faculty of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Brazil.
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Gallo
Department of Physical Therapy, Cardiovascular Physical Therapy Laboratory, Nucleus of Research in Physical Exercise, Federal University of Sao Carlos - UFSCar, Sao Carlos, Sao Paulo, Brazil.
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Catai
D015308:Anaerobic Threshold / Q000502:physiology*; D000886:Anthropometry; D002245:Carbon Dioxide / Q000502:physiology; D003430:Cross-Sectional Studies; D004576:Electromyography; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009203:Myocardial Infarction / Q000503:physiopathology*; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange; D012307:Risk Factors
D002245:Carbon Dioxide