Determination of the maximum steady state of lactate (MLSS) in saliva: an alternative to blood lactate determination.
Based on previous research which shows parallelism between the saliva and blood lactate response during incremental exercise, we hypothesized that a "maximum salivary lactate steady state" (saliva-MLSS) might exist. Thus, the aim of the present investigation was to establish 1) which lower limit for the increase in salivary lactate concentration during a constant workload (i.e., from the 10th to the 20th min) test could be used to determine the saliva-MLSS and 2) if the exercise intensity corresponding to the saliva-MLSS is identical to that evoking the (blood) MLSS. Twelve male amateur athletes of mean ( +/- SD) age 24 +/- 5 year were selected for the study. Based on the results of a previous maximal cycle ergometer test for lactate threshold (LT) determination, each subject performed consecutive constant workload tests of 20-min duration on separate days for MLSS determination. Blood and saliva (25 microl) samples were collected at 0, 10, and 20 min during the tests for lactate determination. A Student's t-test for paired data demonstrated that a salivary lactate increase of 0.8 mM corresponded to the saliva-MLSS. At this value, indeed, no significant differences were observed between the mean V(.)O(2) and W values corresponding to the MLSS and the saliva-MLSS. In conclusion, the present findings indicate that 0.8 mM is the lower limit for the increase in saliva lactate concentration during a constant load test and thus is that which might be used as a reference to determine saliva-MLSS. Furthermore, saliva-MLSS might be used as an alternative to MLSS determination in blood samples.
Pérez
M
M
Departamento de Ciencias Morfológicas y Fisiología, Universidad Europea de Madrid, Madrid, Spain.
Lucía
A
A
Carvajal
A
A
Pardo
J
J
Chicharro
J L
JL
D000328:Adult; D015444:Exercise / Q000502:physiology; D005080:Exercise Test; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D019344:Lactic Acid / Q000097:blood / Q000378:metabolism*; D008297:Male; D009994:Osmolar Concentration; D012463:Saliva / Q000378:metabolism*
D019344:Lactic Acid