Aims: 

Many publications have shown high correlation between serum and saliva lactate level during exercise, but there isn't enough information about lactate level changes in saliva after workloads.

Methods: 

Twenty-seven volunteers (21.79±1.83 years, 14 females, 13 males) performed maximal Astrand treadmill test. Athlete and non-athlete subjects were in the studied group. Saliva and blood samples were collected before and 1st, 4th, 8th, 12th, 15th, 20th mins after the exercise test. Saliva samples were collected in the morning (9.00–12.00 a.m.) by spitting without chemical stimulation into Eppendorf tubes. Blood lactate was measured with a portable lactate analyzer (Lactate Scout, SensLab) immediately after collection. The concentration of saliva lactate was determined by enzymatic spectrophotometric measurements (Hitachi U-2000). Data were analysed with cross correlation test (p<0.05).

Results: 

Two lactate peaks were detected in saliva after the test protocol. Subjects were divided into two groups on the basis of lactate curves. Subjects in the first group (n=12) had a lactate peak one min and a second peak eight min after the test. The first peak might occur from dehydration and an augmented sympathetic tone, while the second peak might show raise of lactate in blood. The lactate increase occurred 3 mins later (average) in the second group (n=6) probably caused by an even stronger sympathetic tone. The average saliva (0.077±0.067–0.262±0.2; 0.111±0.032–0.342±0.158 mM/L) and blood lactate (1.936±0.853–9.478±2.443; 1.629±0.281–9.014±2.479 mM/L) had the same range in both groups. We found a significant correlation between blood and saliva lactate in the first group (r=0.465, p<0.001) after a maximal treadmill test.

Conclusion: 

Our data suggest that measuring saliva lactate might be a suitable method to test the efficiency of training. Further experiments are needed to determine how blood and saliva lactate levels are influenced by physiological factors.