Effects of a Bout of Intense Exercise on Some Executive Functions

Abstract

The present study examined the effects of an exhaustive exercise on executive functions by using the Stroop Color Word Test (SCWT), Trail Making Test (TMT), A and B, and simple Reaction Time (RT). Thirty adults agreed to participate; 15 participants had a mean age of 24.7 years ± 3.2 Standard Deviation (SD, Standard Deviation) (group YOUNG), while the remaining 15 had a mean age of 58.9 years ± 2.6 SD (group OLD). Each subject performed the cognitive tasks at rest and blood lactate was measured (pre); each subject executed the acute exhaustive exercise and, immediately after the conclusion, executed the cognitive tasks and blood lactate was again measured (end). Cognitive tests were repeated and blood lactate measured 15 min after its conclusion of the exhaustive exercise (post). We observed: (1) a significant positive correlation between blood lactate levels and RT levels; (2) a significant negative relationship between levels of blood lactate and the SCWT mean score; (3) no significant correlation between blood lactate levels and TMT scores (time and errors), both A and B; (4) variations in blood lactate levels, due to exhaustive exercise, and parallel deterioration in the execution of RT and SCWT are significantly more pronounced in the group YOUNG than in the group OLD. The present study supports the possibility that high levels of blood lactate induced by an exhaustive exercise could adversely affect the executive functions pertaining to the prefrontal cortex.

Keywords: blood lactate; elderly sport; executive functions; exhaustive exercise; fatigue; young sport.

Figure 1

Blood lactate values of the 15 subjects of group YOUNG (a) and of the 15 subjects of group OLD (b) performing an exhaustive exercise. In both cases, blood lactate mean values measured before the exercise (pre), at its conclusion (end), as well as 15 min after its end (post) are illustrated. Symbols from ANOVA with Dunn’s multiple comparison test: *** p < 0.001.

Figure 2

Values of RT exhibited by the 15 subjects of group YOUNG (a) and by the 15 subjects of group OLD (b) performing an exhaustive exercise. In both cases, RT mean value measured before the exercise (pre), at its conclusion (end), as well as 15 min after its end (post) are displayed. Symbols from ANOVA with Dunn’s multiple comparison test: * p < 0.05, ** p < 0.01, *** p < 0.001.

Figure 3

Values of SCWT mean score exhibited by the 15 subjects of group YOUNG (a) and by the 15 subjects of group OLD (b) performing an exhaustive exercise. In both cases, SCWT mean score measured before the exercise (pre), at its conclusion (end), as well as 15 min after its end (post) are shown. Symbols from ANOVA with Dunn’s multiple comparison test: * p < 0.05, ** p < 0.01, *** p < 0.001.

Figure 4

TMT-A. Execution time (a,b) and number of errors (c,d) found in the 15 subjects of group YOUNG (a,c) and in the 15 subjects of group OLD (b,d) performing an exhaustive exercise. Mean values measured before the exercise (pre), at its conclusion (end), as well as 15 min after its end (post) are shown. Symbols from ANOVA with Dunn’s multiple comparison test: * p < 0.05.

Figure 5

TMT-B. Execution time (a,b) and number of errors (c,d) found in the 15 subjects of group YOUNG (a,c) and in the 15 subjects of group OLD (b,d) performing an exhaustive exercise. Mean values measured before the exercise (pre), at its conclusion (end), as well as 15 min after its end (post) are shown. Symbols from ANOVA with Dunn’s multiple comparison test: * p < 0.001.

Figure 6

Correlations between blood lactate levels and performances at RT, SCWT, TMT-A and TMT-B in the 15 subjects of group YOUNG (a) and in the 15 subjects of group OLD (b).