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Revista Brasileira de Medicina do Esporte
On-line version ISSN 1806-9940
ZAGATTO, Alessandro Moura et al. Comparison between the use of saliva and blood for the minimum lactate determination in arm ergometer and cycle ergometer in table tennis players. Rev Bras Med Esporte [online]. 2004, vol.10, n.6, pp. 475-480. ISSN 1806-9940. http://dx.doi.org/10.1590/S1517-86922004000600004.
The aim of this study was to verify if it is possible to determine the lactate minimum test (LMT) by saliva sodium (Na+), potassium (K+) and lactate (LAC) concentrations in arm ergometer and cycle ergometers. Eight male international-level table tennis players participated in this study. To induce increases of lactate concentration in both ergometers, 30 seconds maximal tests were used with maximal force application in constant 102 rpm in isokinetic arm ergometer (Cybex UBE 2432), and loads of 7.5% of body weight (Kp) in cycle ergometer (mechanical Monark). After the anaerobic stimulus in arm ergometer, the incremental test was applied at constant 60 rpm, started at 49 watts and increment loads of 16 watts each three minutes. The LMT intensity was determined with the analysis of the blood lactate (LACminarm) and the saliva concentrations of sodium (Na+minarm-saliva) and potassium (K+minarm-saliva). For the cycle ergometer, the incremental test started with an intensity of 85 watts and increments of 17 watts at constant speed of 70 rpm. The stages were also of three minutes. The LACmin was determined using blood and saliva samples (LACmincycle; Na+mincycle-saliva, K+mincycle-saliva and LACmincycle-saliva, respectively). In both ergometers, the intensity obtained in lactate minimum test was correspondent to zero derived polynomial adjustments by metabolite concentrations versus exercise intensities. The statistical analysis included one way ANOVA test, paired t-test and Pearson's correlations. For all tests applications, the significance level was prefixed at 5%. The several LACmin determinations using blood and saliva samples did not show significant differences in arm and cycle ergometers (LACminarm 91.71 ± 12.43; Na+minarm-saliva 71.99 ± 23.42; K+minarm-saliva 79.67 ± 17.72; LACmincycle 157.68 ± 13.48; LACmincycle-saliva 135.49 ± 33.2; Na+mincycle-saliva 121.81 ± 51.31; K+mincycle-saliva 135.49 ± 33.21 watts). However, these intensities presented no significant correlations. These results showed that determination of the LMT by saliva lactate, sodium and potassium concentrations seems not to be possible with the use of isokinetic arm ergometer and cycle ergometers.
Keywords : Lactate; Sodium; Potassium; Anaerobic threshold.