Author(s): HUANG, J., LIU, Z., HU, M., Institution: GUANGZHOU SPORT UNIVERSITY, Country: CHINA, Abstract-ID: 270

INTRODUCTION:
The study aimed to explore the impacts of acute high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) on different executive functioning skills and the underlying regulatory mechanisms in sedentary young individuals.
METHODS:
Fifteen participants (10M/5F; 22±2 years; BMI: 23.07±4.12 kg/m2) participated in a single-blind, randomized crossover experimental design including three experimental conditions: HIIE, MICE, and a control session of rest (CON) in random order separated by a 7-day washout period. Executive functioning skills were assessed using Stroop task (inhibition control), N-back task (working memory), and Switching task (cognitive flexibility). The oxyhemoglobin concentration (Oxy-Hb) levels of prefrontal cortex were assessed by functional near-infrared spectroscopy (fNIRS). Biomarkers of cognitive function, including BDNF and blood lactate, were measured using enzyme-linked immunosorbent assays (ELISA).
RESULTS:
For inhibitory control, both HIIE and MICE significantly reduced reaction times in congruent and incongruent tasks, however, only HIIE shortened reaction time in Stroop interference task. Furthermore, both acute HIIE and MICE significantly reduced reaction times in 3-back task of working memory and in single and mixing trial tasks of cognitive flexibility. Under Stroop task, Oxy-Hb level in the OFA region significantly increased after both HIIE and MICE, but Oxy-Hb level in the FPA region only significantly increased after HIIE. Under N-back task, only HIIE significantly increased the Oxy-Hb level in the R-DLPFC region. Under Switching task, Oxy-Hb level in the FPA region significantly increased after both HIIE and MICE, however, Oxy-Hb levels in the PTR region and R-DLPFC region only significantly increased after HIIE. Compared to the baseline level, circulating BDNF and lactate levels significantly increased in both HIIE and MICE, with a greater extent after HIIE compared to MICE in lactate. Notably, exercise-induced increase in executive functioning skills was correlated with enhanced Oxy-Hb, BDNF, and lactate levels.
CONCLUSION:
Both acute HIIE and MICE have a positive influence on all three executive functioning skills in sedentary young individuals, and acute HIIE seems have a greater impact on executive functioning skills and their relevant cerebral haemodynamics and neuroregulatory factors. Importantly, the increases in lactate and its mediated BDNF release, may be contributed to the increase in blood oxygen levels in specific brain regions, which collectively enhance executive functioning skills.