Anaerobic Threshold by Mathematical Model in Healthy and Post-Myocardial Infarction Men

Abstract

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.

Comparaison des méthodes de détermination des seuils ventilatoires: implications pour la stratification du risque chirurgical

“…The inclusion of a relatively large sample of presurgical AAA subjects overcomes one of the limitations in previous studies, that is, comparing different methods of determining VT among young healthy subjects. 11,[20][21][22][33][34][35][36][37] In general, our findings are consistent with previous reports showing fairly good agreement between different methods of determining VT. 11,19,22,[33][34][35]37 In this regard, several studies have shown moderately high correlation (r = 0.59-0.98) between computed mathematical models, and visual readings of the VT, lactate responses, or both. 11,19,22,[33][34][35]37 Nevertheless, these relatively high associations between methods are contrasted by several other studies reporting poor agreement.…”

“…22,33,34,36,37 ) observed using a cycle ergometer test among surgical candidates with high perioperative risk. This reflects the 10-25% higher values typical for treadmill testing vs the cycle ergometer.…”

Expiratory Flow Limitation at Different Exercise Intensities in Coronary Artery Disease

“…Symptom-limited CPET was performed on a treadmill (Master ATL, Inbramed, Porto Alegre, Rio Grande do Sul, Brazil). e ramping protocol was based on a previous study [18] (respecting the maximal walking velocity without running) with objective to identifying the value of ventilatory anaerobic threshold (VAT) [2,[25][26][27][28] of each participant.…”

“…Data were analyzed after smoothed by moving averages of eight respiratory cycles [25]. Using the ventilatory method, three independent evaluators determined the VAT [25,27,28]. Oxygen uptake (VO 2 ), VCO 2 (carbon dioxide production), and respiratory exchange ratio (RER) (defined as the ratio between VCO 2 and VO 2 ) of the peak were expressed as the highest averaged values observed during the last 30 s of exercise [18,19].…”

Non-exhaustive double effort test is reliable and estimates the first ventilatory threshold intensity in running exercise

“…In this regard, detection of maximal oxygen consumption (VO 2max ) and aerobic and anaerobic thresholds are the main determinants of aerobic fitness in athletes, 2 , 3 subjects with impaired health, 4 , 5 and healthy individuals. 6 , 7 …”