Higher levels of cardiovascular fitness are associated with better executive function and prefrontal oxygenation in younger and older women

Abstract

Aim: Many studies have suggested that physical exercise training improves cognition and more selectively executive functions. There is a growing interest to clarify the neurophysiological mechanisms that underlie this effect. The aim of the current study was to evaluate the neurophysiological changes in cerebral oxygenation associated with physical fitness level and executive functions.Method: In this study, 22 younger and 36 older women underwent a maximal graded continuous test (i.e., trueV˙O2max) in order to classify them into a fitness group (higher vs. lower fit). All participants completed neuropsychological paper and pencil testing and a computerized Stroop task (which contained executive and non-executive conditions) in which the change in prefrontal cortex oxygenation was evaluated with near infrared spectroscopy (NIRS).Results: Our findings revealed a Fitness × Condition interaction (p < 0.05) such that higher fit women scored better on measures of executive functions than lower fit women. In comparison to lower fit women, higher fit women had faster reaction times in the Executive condition of the computerized Stroop task. No significant effect was observed in the non-executive condition of the test and no interactions were found with age. In measures of cerebral oxygenation (ΔHbT and ΔHbO2), we found a main effect of fitness on cerebral oxygenation during the Stroop task such that only high fit women demonstrated a significant increase in the right inferior frontal gyrus.Discussion/Conclusion: Higher fit individuals who demonstrate better cardiorespiratory functions (as measured by trueV˙O2max) show faster reaction times and greater cerebral oxygenation in the right inferior frontal gyrus than women with lower fitness levels. The lack of interaction with age, suggests that good cardiorespiratory functions can have a positive impact on cognition, regardless of age.

The relationship between exercise intensity, cerebral oxygenation and cognitive performance in young adults

“…Our findings are in line with Dupuy et al (2015), who found that higher-fit individuals who demonstrate better cardiorespiratory functions show faster reaction times and greater cerebral oxygenation. Similarly, our results align with Prakash et al (2011), who reported a greater blood oxygen level-dependent (BOLD) signal increases in the prefrontal cortex during the Executive Stroop conditions for individuals who demonstrated a higher cardiorespiratory function.…”

Associations among executive function, cardiorespiratory fitness, and brain network properties in older adults

“…Recently, the relationship between aerobic fitness level and level of EF was found to be mediated by frontal lateralization (i.e., compensatory neural recruitment) in older adults24 in accordance with the hemispheric asymmetry reduction in older adults (HAROLD) model2526. Dupuy, et al 27. found significant positive associations among physical fitness, frontal brain oxygenation, and EF, suggesting, in accordance with previous studies, that a higher level of cardiorespiratory fitness is related to higher task-evoked hemodynamic responses in frontal areas.…”

Mediators of Physical Activity on Neurocognitive Function: A Review at Multiple Levels of Analysis

“…The pattern of results reported in these cross-sectional studies supports the argument that PA influences cognition through its effects on the functional allocation of neural resources (i.e., functional activation) during cognitive tasks. The results of several other cross-sectional studies assessing links between fitness, neural functioning, and cognition provide support for this general idea (Dupuy et al, 2015; Gauthier et al, 2015). However, these studies did not fully test for mediation because they either did not observe or did not test for the prerequisite correlations amongst the variables.…”