Comparação de diferentes métodos para determinar o limiar de anaerobiose de idosos saudáveis
Abstract
Some studies have been conducted with the objective of applying mathematical
models to the data of HR, CO2 and RMS of myoelectric signal to determine a shift
point on their behaviors during exercise and characterize metabolic changes which
occur at the anaerobic threshold level (AT), saving time and optimizing the
conventional analysis process which, by financial reasons, has become restricted
to few research centers. The objective of the present study was to determine the
anaerobic threshold applying two mathematical models, Heteroscedastic and
Hinkley, to a set of HR, RMS and CO2 data. Methods: 9 active elderly subjects
were studied (61,4 ±1,8years) during continuous physical ramp load test on cycle
ergometer, with power ranging from 10 to 15 Watts/min. FC data was collected
beat to beat and ventilatory variables breath to breath. After the application of
mathematical models to these variables and the identification of the behavior shift
points, the power levels, HR and O2 were registered, compared and co-related to
those obtained by the graphic visual model. Statistic methodology: The Friedman
test was used to make multiple comparisons and the Spearman co-relation test
(5%) to verify the adjustment of the models to the variables. Results: no significant
differences were found (p>0,05) in relation to the gold standard, between the
power levels, O2 and HR during the LA shift identified by the different models.
Significant correlated data were found between the HR values identified by the
mathematical models applied to the HR and O2 data, between the values of O2
when identified by the HR, and between power rates only when identified by the
Hinkley model applied to data of RMS of the myoeletric signal. Conclusion: in the
sample study, the mathematical models appeared adequate in determining noninvasive
AT. Both models adjusted better to the HR data, followed by CO2 and RMS.