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Revista Brasileira de Medicina do Esporte
On-line version ISSN 1806-9940
SANTHIAGO, Vanessa; SILVA, Adelino Sanchez Ramos da; GUGLIELMO, Luiz Guilherme Antonacci and HIGINO, Wonder Passoni. Influence of the acidosis induction manner in the determination of minimal lactate threshold in endurance runners. Rev Bras Med Esporte [online]. 2008, vol.14, n.4, pp. 393-398. ISSN 1806-9940. http://dx.doi.org/10.1590/S1517-86922008000400014.
The purpose of this study was to verify if different induction forms to the acidosis can interfere in the determination of the minimum lactate (LACmin) intensity in endurance runners. Fourteen male endurance runners took part in as subjects of this study. The athletes accomplished three protocols: 1) a incremental exercise test in treadmill running, with increments of 1 km.h-1 at each 3 minutes, to determine the running velocity of anaerobic threshold (OBLA), aerobic threshold (Laer), maximal oxygen consumption (VO2max) and maximum consumption speed of oxygen (vVO2max); 2) a lactate minimum test with inducing lactic acidosis in athletics track (LACminp), that it constituted of two maximum efforts of 233m with interval of 1 minute, with 8 minutes of passive recovery, followed by a incremental exercise test similar to the first protocol, and 3) a lactate minimum test with inducing lactic acidosis in treadmill running (LACmine), constituted by two maximum efforts of 1 minute and 45 seconds with interval of 1 minute, in the running speed of 120% of the vVO2max, followed by the same procedures of the second protocol. Samples of blood were collected from the earlobe to the end of each loads of 3 minutes in all the protocols and in the 7th minute of recovery of the tests of the LACmine and the LACminp. The variance analysis (ANOVA) showed that there were significant differences between the speeds of LACmine (13,23 ± 1,78 km.h-1) and OBLA (14,67 ± 1,44 km.h-1). These results suggest that the determination of the running speed corresponding to the lactate minimum is dependent of the protocol used for the inducing lactic acidosis. Besides, LACmine underestimated the running speed corresponding to OBLA and should not be used to measure the aerobic capacity in long distance runners.
Keywords : running; anaerobic threshold; maximal oxygen uptake.