Executive Functions During Submaximal Exercises in Male Athletes: Role of Blood Lactate

FIGURE 1. Schematic representation of the experimental protocol. Blood lactate levels were quantified before the exercise (pre), every 10 min during exercise (during), immediately at the end of exercise (end), and finally, 10 min after exercise was completed (post). The Simple Reaction Time, Stroop Color Word Test, and Trial Making Test were measured immediately at the end of the exercise (end) and 10 min after the exercise was completed (post).

FIGURE 2. Blood lactate levels (mean values ± SD) of the 20 participants performing a voluntary 30-min exercise at 60 and 80% VO2max. Measurements were carried out every 10 min before the exercise (pre), during the 30-min exercise, and 10 min after the conclusion (post). The dotted line indicates the level (4 mmol/l) of the Onset of Blood Lactate Accumulation (OBLA). Results of Tukey’s Multiple Comparison Test carried out on data are also presented. ANOVA with Tukey’s multiple comparison test are the following: ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001.

FIGURE 3. Mean values (±SD) of blood lactate, reaction time, Stroop test, and time for execution of Trial Making Test B of the 20 participants performing a voluntary 30-min exercise at 60 and 80% VO2max. Measurements were taken 10 min before (pre) the beginning of exercise (gray area), at its end and 10 min after the conclusion (post). The dotted line indicates the level (4 mmol/l) of OBLA. Symbols from ANOVA with Tukey’s multiple comparison test: ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001.

FIGURE 4. Correlations between blood lactate levels and performance measured for RT, SCWT, and TMT-B in the two different exercise intensities (60% of VO2max on the left and 80% of VO2max on the right). As can be seen, while at 60% of VO2max none of the correlations reaches statistical significance, at 80% of VO2max the 3 correlations are statistically significant (P > 0.05).