Effects Of Two-week High-intensity Intermittent Exercise On Inhibition Control,Working Memory Function And Motor Cortex Plasticity In Sedentary Female College Students

Purpose:The aim of this study was to assess the effects of two-week high-intensity intermittent exercise on executive function（mainly including inhibitory control and working memory function）and motor cortex plasticity in sedentary female college students,and functional near-infrared spectroscopy（fNIRS）was used to monitor changes in brain oxygenation during the task to further explore the neural mechanism of performing functional changes after two-week high-intensity intermittent exercise.Method:Thirty-two sedentary female college students of non-sports major from Nanjing Institute of physical Education were selected as subjects,aged 18-21 years.They were randomly divided into high-intensity intermittent exercise group（HIIT group,n=16）and control group（CON group,n=16）.HIIT group completed a two-week high-intensity intermittent exercise program,including 4 times a week for 20 minutes each time for a total of 8 power cycling exercises,while the control group studied and lived normally.Before and after exercise intervention,the subjects underwent physical function test,neurocognitive test,functional infrared spectrum（fNIRS）test and transcranial magnetic stimulation（TMS）tset.Physical function tests included resting heart rate（RHR）,blood pressure（DBP/SBP）and maximal oxygen intake（VO2max）;neurocognitive tests included:Stop-signal task and spatial n-back tasks and Stroop task;fNIRS tset mainly measured changes in the concentrations of cerebral oxyhemoglobin（[HbO]）and deoxyhemoglobin（[HbR]]during the Stroop task;TMS test mainly included:short interval intracortical inhibition（SICI）and intracortical facilitation（ICF）.SPSS 19.0 statistical software was used for analysis of the data.Shapiro-Wilk test is used to detect the normal distribution of each group of data,and nonparametric test is used to detect the data of non-normal distribution.For the changes of various physical function indexes,paired sample t test was used for intra-group comparison,and independent sample t test was used for inter-group comparison.The indexes of neurocognitive test and motor cortex plasticity were analyzed by repeated ANOVA.If there was no interaction,the main effect was analyzed.All the test data had significant difference levels of p<0.05 and very significant difference levels of p<0.01.Result:1.Compared with the pretest,the RHR of the HIIT group decreased significantly（p<0.05）,and VO₂max increased significantly（p<0.05）;the RHR difference between the HIIT group and CON group was significantly different（p<0.05）,the VO₂max difference between the HIIT group and the CON group was marginally significant（p=0.08）.2.In the stop-signal task,there was a significant main effect by time（p<0.05）,the SSRT of the two groups in the post-test is significantly lower than the pre-test（p<0.05）,and no significant main effect by group on SSRT（p>0.05）,there was no interaction between time and group on SSRT（p>0.05）.In spatial n-back tasks,there was interaction between time and session on response time（RT）and accuracy（ACC）（p<0.05）.group and time,group and session had no interaction on RT and ACC（p<0.05）,there was no interaction between time,group and session factors on RT and ACC（p>0.05）.In the Stroop task,the main effects and interaction effects of the group and time were not significant in terms of response time and accuracy（P>0.05）.3.Compared with the pretest,the[HbO]of the left DLPFC in the HIIT group increased significantly（P<0.05）,and the[HbO]of the OFC on the left increased significantly（P<0.01）,and the HIIT group The[HbO]of the left DLPFC was significantly higher than that of the CON group（P<0.05）.4.Compared with the pretest,the SICI of the HIIT group had a very significant decrease（p<0.01）,and the ICF also had a very significant decrease（p>0.05）,and the ICF between the HIIT group and the CON group had a significant difference during the posttest P<0.05）.Conclusion:Two-week high-intensity intermittent exercise can significantly reduce the resting heart rate of sedentary female college students and increase the maximum oxygen uptake,thus contributing to enhance cardiopulmonary adaptability.2.Two-week high-intensity intermittent exercise had no significant effect on the behavioral changes of executive function of sedentary female college students,but a higher activation of the left dorsal lateral prefrontal cortex was observed during the Stroop task.3.Two-week high-intensity intermittent exercise may induce plasticity enhancement effects in the motor cortex by reducing short-interval intracortical inhibition and intracortical facilitation in sedentary female college students.