Effects Of Four-week Aerobic Exercise On Mood,working Memory,and Decision-making In College Students Under Acute Stress

Objectives:Acute stress affects the emotional processing system and executive decision-making system,and studies have shown that regular aerobic exercise can improve negative emotions such as anxiety or depression,and improve executive functions such as inhibitory control,working memory and cognitive flexibility.However,the impact of aerobic exercise on decision-making under acute stress is not well understood.Therefore,this paper uses randomized controlled experiments to measure the effects of aerobic exercise on emotional changes,working memory and cognitive decision-making in college students under acute stress,and uses functional near-infrared spectroscopy(f NIRS)to measure the change of cerebral blood oxygen concentration during decision-making,so as to explore how aerobic exercise affects the reward effect and goal orientation under acute stress.Method:41 college students without habitual exercise were recruited,with an average age of 22.4±2.07 years.Participants were randomly divided into two group:moderate-intensity continuous training group(MICT group,n=21)and control group(CON group,n=20).The first group needed to complete a 4-week moderate-intensity exercise regimen,including 35 minutes per time,3 times a week,and the intensity was controlled at 65%reserve heart rate.The second group maintained the previous life routine.Using time-limited computation and memory tasks as acute stress tasks,participants’stress levels(including state-anxiety,VAS and HRV),after stress tasks working memory,decision-making,and oxygenated hemoglobin(HBO)and deoxyhemoglobin(HBR)concentrations in the prefrontal cortex during the decision-making were recorded before and after the intervention.The data were statistically analyzed by Jamovi 2.2.5 statistical software,the normal distribution was tested by Shapiro-Wilk,and the non-normal distribution data was tested by the nonparametric Mann-Whitney U.The independent sample t-test was used to detect the between-group effect,Paired-sample t-test was used to detect within group effect.State-anxiety,VAS,and HRV,as well as working memory and decision-making,were analyzed using repeated measures of ANOVA.Hybrid linear models were used to analyze NIR data.p>0.05 is no significant difference,and p<0.05 is significant difference.Results:After the acute stress task,state-anxiety,emotional negativity,emotional intensity and low-frequency LF(norm)were significantly increased,HF(norm)was significantly reduced,and LF/HF ratio was increased(p<0.05).It was then verified whether aerobic exercise interventions relieved stress?The results show that:1.There was no significant difference in state-anxiety between the two groups in the pre-test(F=0.058,p=0.811),while the state-anxiety change in the MICT group was significantly lower than CON group in the post-test(F=8.873,p<0.01).2.No significant was found on VAS or HRV(p>0.05).3.The absolute span scores of working memory in the MICT group shows marginal salience(p=0.085).4.Regarding the reward effect,the time*group interaction effect was significant(F=4.432,p=0.042,η2_p=0.10),and the reward effect in the CON group was significantly increased than pre-test(t=2.34,p=0.031),while the goal-oriented behavior of two groups were not significant(p>0.05).5.The significant changes in PFC activation levels in both groups were mainly concentrated in OFC(p<0.05).Under reward conditions,brain region activation was concentrated in OFC,and there was no significant difference between the two groups(p>0.05).Although exercise intervention did not significantly alter goal-oriented behavior,OFC oxygen level signaling increased in the MICT group,compared with the CON group(p<0.05).Conclusion:(1)Acute stress tasks can effectively induce psychological stress in participants without exercise habits.(2)4 weeks of moderate-intensity aerobic exercise relieved participants’state anxiety under acute stress.(3)4 weeks of moderate-intensity aerobic exercise tended to improve participants’working memory under acute stress.(4)4 weeks of moderate-intensity aerobic exercise improved the reward effect under acute stress.(5)Under goal-oriented conditions,4 weeks of moderate-intensity aerobic exercise shifted PFC-active areas to OFC and it involved participation in the reward process.