OBJECTIVE: To determine the anaerobic threshold by the graphic visual ventilatory method and the Hinkley and heteroscedastic mathematical models, applied to heart rate, myoelectric root mean square (RMS) signal and VCO2 datasets, and to compare the anaerobic threshold obtained by the three methods. METHOD: Nine active elderly subjects were studied (aged 61.4 ± 1.8 years) during a ramp-load continuous dynamic physical exercise test on a cycle ergometer, with power ranging from 10 to 15 Watts/min. Beat-to-beat heart rate data, electromyographic data from the surface of the vastus lateralis muscle, and breath-to-breath ventilatory data were collected. After applying mathematical models and identifying the behavioral shift points, these power levels, heart rates and VO2 values were noted and these were compared and correlated with those obtained by the graphic visual model (gold standard). The Friedman test for multiple comparisons and the Spearman correlation test were utilized (significance level: 5%). RESULTS: No significant differences were found in relation to the gold standard, between the power levels, VO2 values and heart rates at the anaerobic threshold identified by the different models. Significant correlations were found between the heart rates identified by the mathematical models, between the VO2 values identified by the heart rates, and between power rates only when identified by the Hinkley model applied to myoelectric RMS signal data. CONCLUSION: In this study group, the mathematical models were shown to be adequate for non-invasively determining the anaerobic threshold. Both models worked best on the heart rate data, followed by VCO2 and RMS.
anaerobic threshold; mathematical models; elderly people
