تعيين آستانه بي هوازي از راه كنترل شاخص درصد SPO2 و تغييرات پارامترهاي گازي در مردان فعال

The Determination of Anaerobic Threshold by Monitoring % SP02 Changes and Pulmonary Gas Exchanges in Active Men

Several methods, both invasive and non - invasive, have been used for estimating the anaerobic threshold, and there is no consensus about what is the best procedure. The aim of this study was the determination of anaerobic threshold by %SP02 (percent saturation of Hb with 02) changes, and comparison of three common methods in evaluation of anaerobic threshold by pulmonary gas exchanges. 15 active men volunteered to participate in this study and did three incremental tests, at least with 48h interval. Respiratory parameters were measured breath by breath, heart rate was measured continuously every five seconds, and blood samples were collected every third minutes. Finally %SP02 changes were measured continuously throughout the gas analysis test every ten second using pulse oximeter. Anaerobic threshold was determined based on:I. Blood lactate concentration (lactate threshold), 2. respiratory exchange ratio (RER threshold), 3. V-Slope method (v-slope threshold), 4. %SP02 changes (spo2 threshold), 5. Ventilatoty equivalent for 02 (ve / ve2 threshold). Equivalent of each factor including oxygen, heart rate, lactate and speed, for anaerobic threshold, was calculated in each test. The correlations among variables were made by pearson correlation coeficience test and regression analysis was performed to determine the ability of prediction. The difference among variables was determined by paired t - test. Significant correlation was found between RER threshold and lactate threshold (r = 0.784, p<0l), ve / vo2 threshold and lactate threshold (r = 0.731, p< 01), v - slope threshold and lactate threshold (r = 0.59, P<05), Spo2 threshold and lactate threshold (r = 0.61, P<.05). The results indicated that determination of anaerobic threshold well correlates with the blood lactate - based anaerobic threshold and in the present study, it seemed to be the best respiratory index for estimation of anaerobic threshold. An other finding was that it is possible to estimate the lactate threshold heart rate with 95% confidence considering the heart rate of the RER threshold.