Effects Of Acute Exercise With Different Modalities On Executive Function In Adolescents With High And Low Cardiorespiratory Fitness

Background: With the growing research on physical activity for mental health,the relationship between physical activity and adolescent cognitive function has gained popular interest.Executive function,as a higher cognitive function in humans,is closely related to motor skill learning,academic success,physical and mental health,and social relationships in adolescents.How to establish effective physical activity programs to improve executive function in adolescents with different levels of cardiorespiratory fitness is a crucial research question.Objectives: This study used a behavioral task and aimed to determine the effects of high-intensity interval exercise(HIIE)and moderate-intensity continuous exercise(MICE)on executive function in individuals with high and low cardiorespiratory fitness.Methods: This study was conducted on 66 adolescents aged 14-17 years.A mixed experimental design of 4(intervention modes: 10 min HIIE,20 min HIIE,20 min MICE,and Control group)× 2(cardiorespiratory fitness level: high,low)× 2(measurement time:pre-intervention,post-intervention)was used.The adolescents’ cardiorespiratory fitness was determined based on maximum oxygen uptake assessed in a 20-meter shuttle run,resulting in 33 participants in each of the high and low cardiorespiratory fitness groups.All adolescents were required to participate in four interventions and complete executive function tasks to assess executive function performance(a spatial 2-back task to assess working memory,a color-word Stroop task to assess inhibitory control,and a more-odd shifting task to assess cognitive flexibility)before and immediately after the intervention.The Physical Activity Enjoyment Scale and the Rating of Perceived Exertion Scale were each completed immediately after exercise to evaluate the emotional experience of adolescents during exercise and their perception of exertion and fatigue during exercise,respectively.Results:(1)Analysis of the 2-back task revealed that the high cardiorespiratory fitness group had a faster 2-back task reaction time after the 20 min HIIE intervention than before the intervention(p < 0.001),whereas the low cardiorespiratory fitness group had a faster 2-back task reaction time after both the 10 min HIIE(p < 0.001)and 20 min MICE(p < 0.001)interventions than before the intervention.(2)Analysis of the color-word Stroop task found that reaction time in the incongruent condition was significantly faster after all three exercise interventions than before the intervention(p ≤ 0.037),whereas reaction time in the incongruent condition did not significantly change before and after the intervention in the control group(p = 0.921).(3)Analysis of the more-odd shifting task found that the switch condition response time was faster in the high cardiorespiratory fitness group after the 20 min HIIE intervention than before the intervention(p < 0.001),whereas the switch condition response time was shorter in the low cardiorespiratory fitness group after both the 10 min HIIE(p < 0.001)and 20 min MICE(p < 0.001)interventions than before the intervention.In addition,switch cost was lower in the high cardiorespiratory fitness group after the 20 min HIIE intervention than before(p = 0.001)and in the low cardiorespiratory fitness group after the 10 min HIIE intervention than before(p < 0.001).Conclusions: Acute exercise improved executive function in adolescents.The benefits of acute exercise on working memory and cognitive flexibility in adolescents with high and low cardiorespiratory fitness were moderated by the modality of acute exercise,as demonstrated specifically by 20 min HIIE improving working memory and cognitive flexibility in the high cardiorespiratory fitness group,while 10 min HIIE and 20 min MICE improved working memory and cognitive flexibility in the low cardiorespiratory fitness group.All three exercise interventions improved inhibitory control in adolescents with high and low cardiorespiratory fitness,and their benefits were not affected by the modality of acute exercise.This finding has important implications for providing experimental evidence that participants choose the appropriate exercise to undertake based on their level of cardiorespiratory fitness to improve cognitive performance.