it has been reported that childhood participation in physical activity , including regular 
 exercise , could not only promote physical development1 , but could also prevent various diseases , such as metabolic 
 syndrome , by improving body composition and enhancing health - related physical fitness2 . in addition , there are recent reports that 
 childhood participation in physical activity might have a positive effect on cognitive 
 function , on various academic achievements , including academic score , and on psychosocial 
 function3 , 4 . specifically , lees and hopkins reported that aerobic physical 
 activity had a positive correlation with cognition , academic achievement , behavior , and 
 psychosocial functioning outcomes . similarly , based on their finding that children with high 
 aerobic capacity scored higher than average in mathematics , desai et al . suggested that 
 proper participation in physical activity at school might have potential benefits for 
 academic achievement , although the mechanism of this impact was not clear . on the other hand , taekwondo ( tkd ) , a globally popular sport , is practiced by about 70 
 million people in 204 countries , and 380 thousand children apply for a taekwondo belt test 
 every year5 . preceding studies have 
 reported that regular tkd training had a positive effect on the improvement of physical 
 fitness and on physical growth and development in children5 ; and that childhood tkd training was effective in facilitating 
 physical , cognitive , emotional , and social development  for example , by reducing anxiety , 
 encouraging independence and leadership , and controlling aggression6 , 7 . a recent study by 
 kim et al . using functional mri verified the positive effect of tkd training on brain 
 development in children . the results showed improvement in brain connectivity from the 
 cerebellum to the parietal and frontal cortex . this suggests that tkd training may be 
 effective in improving cognitive function and academic capability in children . however , there has been very limited research to verify the effect of tkd training on 
 academic capability and the development of cognitive function in growing children . accordingly , the present study was conducted on children in elementary grades 46 , aiming to 
 verify the effect of tkd training on their cognitive function and academic 
 self - efficacy . thirty - five healthy children aged 10 to 12  years volunteered as subjects for this study . eighteen children ( 10 boys and 8 girls , mean age : 11.4  0.7  years , mean height : 149.2  
 6.7  cm , mean weight : 45.8  6.7  kg , mean bmi : 20.5  2.0  kg / m ) received no 
 intervention and served as the control group . seventeen children ( 11 boys and 6 girls , mean 
 age : 11.2  0.8  years , mean height : 148.8  7.7  cm , mean weight : 46.9  8.6  kg , mean bmi : 
 21.2  3.9  kg / m ) received tkd training intervention for 16 weeks ( tkd group ) . the study protocol was approved by an institutional ethics review board of the youngsan 
 university . all subjects and their parents were informed about the research procedure and 
 possible risks involved , and both parents and subjects signed a written consent form . tkd training was conducted 5 times per week , for 16 weeks , each time for 70 minutes , at an 
 exercise intensity of 5080% of hrmax . specifically , each tkd training session involved 5 
 minutes of warm - up stretching , 10 minutes of basic physical fitness training , 40 minutes of 
 main exercise ( consisting of basic tkd movements , poomsae , kicks , and taekwon gymnastics ) , 
 and 5 minutes of cool - down stretching . for measuring cognitive function , the stroop color and word test was performed twice , 
 before and after intervention , as previously described8 . the tests comprise word reading , color reading , and color - word 
 reading parts . academic 
 self - efficacy was measured using the scale developed by kim and park , which consists of 3 
 subordinate factors : self - confidence , self - regulatory efficacy , and task difficulty 
 preference . statistical analyses were performed using spss version 21.0 for windows ( spss inc . , 
 chicago , il , usa ) . data have been presented as the mean  standard deviation , unless stated 
 otherwise . for identifying differences in normally distributed results , the two - way repeated 
 analysis of variance ( anova ) when significant group by time interactions 
 occurred , simple main effects were assessed using the independent and paired t - tests . a comparison of anthropometric characteristics , stroop color and word test scores , and 
 academic self - efficacy scores for the two groups before and after intervention has been 
 presented in table 1table 1.a comparison of anthropometric characteristics , 
 stroop color and word test scores , and academic self - efficacy scores for two groups 
 before and after interventionvariablescontrol group ( n=18)tkd group ( n=17)beforeafterbeforeafterheight ( cm)149.2  6.7150.1  6.6148.8  7.7150.2  7.3weight 
 ( kg)45.8  6.746.9  6.946.9  8.647.3  7.7bmi ( kg / m)20.5  2.020.7  1.921.2  3.921.0 
  3.6word test ( score)71.2  
 8.872.2  7.771.6  10.273.7  9.1color test ( score)51.2  6.751.9  6.652.1 
  6.753.9  5.9color - word 
 test ( score)35.2  4.535.6  
 5.035.4  4.936.8  
 4.3self - confidence ( score)3.5  0.83.7  0.73.4 0.74.1  0.7self - regulatory efficacy ( score)3.4  0.63.4  0.63.4  0.73.8  
 0.7task difficulty preference ( score)3.1  0.93.3  0.73.1  
 0.83.5  
 0.7data are presented as mean  standard 
 deviation . the color - word scores and self - confidence scores increased significantly 
 after intervention as compared to those before intervention ( p<0.05 ) . however , there were 
 no significant differences in height ; weight ; bmi ; and scores on the word , color , 
 self - regulatory efficacy , and task difficulty preference tests ( p>0.05 ) . the advancement of life science has brought about the development of new technologies that 
 enable the morphometric analysis of the brain  such as image analysis technology . accordingly , many preceding studies have reported the brain health improvement effect of 
 exercise . for example , regular exercise has been reported to exert a positive effect on 
 functional changes in the brain , by not only improving brain volume but by also inducing 
 angiogenesis and neurogenesis10 , 11 . the present study employed the stroop 
 color and word test to verify the effect of tkd training on cognitive function in children . the result showed that the tkd group achieved significantly higher color - word scores after 
 the 16-week tkd training , suggesting that tkd training may be effective in improving 
 cognitive function . this supports the findings of preceding research that reported 
 significant increase in stroop color and word test scores following regular tkd 
 training12 . the stroop color and word 
 test reflects cognitive function9 . using 
 this test , kim reported a significant increase in color and word scores after an 8-week tkd 
 training at exercise intensities of rpe 1115 . in addition , a study conducted by lakes et 
 al.13 , which involved 60 students in 
 grades 78 and the practice of tkd for 9 months during physical education classes , showed 
 that taekwondo was effective not only in enhancing physical fitness but also in improving 
 cognitive function . based on this result , tkd was suggested to be an appropriate exercise 
 program for physical education at school . academic self - efficacy refers to learner s self - assessment on the ability to confidently 
 organize and execute an action plan for carrying out an academic task , and it consists of 3 
 subordinate factors : self - confidence , self - regulatory efficacy , and task difficulty 
 preference9 . the present study showed 
 that tkd training resulted in a significantly high self - confidence score ( which indicates 
 students confidence or conviction in their own academic capability ) . according to preceding 
 research , there is a direct and indirect correlation between academic self - efficacy and 
 academic achievement , as the learners with higher academic self - efficacy tend to choose more 
 challenging tasks , invest more efforts in successfully carrying out tasks , and use more 
 effective learning strategies9 , 14 , 15 . taken 
 together , these results suggest that tkd training may also be effective for enhancing 
 academic capability in growing children . it has also been reported that the increased 
 expression of neurotrophic factors that occurs with regular exercise plays an important role 
 in the mechanism of brain function improvement16 , 
 17 . therefore , in order to elucidate 
 the mechanism through which tkd training aids the improvement of cognitive function and 
 academic self - efficacy , follow - up research would need to include the analysis of 
 neurotrophic factors . in addition , this study has the limitation that it could not exclude 
 the effect of regular exercise because there was no other exercise group that can be 
 compared with tkd group . in future studies , it is necessary to compare tkd training with 
 other types of exercise programs . in conclusion , it is suggested that regular tkd training may be effective for enhancing 
 cognitive function and academic self - efficacy in growing children .
[ purpose ] the purpose of this study was to investigate the effects of taekwondo training 
 on cognitive function and academic self - efficacy in children . [ subjects and methods ] 
 thirty - five children participated in the study . 
 seventeen children were randomly selected 
 to undergo taekwondo training for 16 weeks ( 5 times per week ) . as controls , 
 18 children 
 received no training . cognitive function and academic self - efficacy 
 were measured using 
 the stroop color and word test ( word , color , and color - word ) and academic self - efficacy 
 scale ( self - confidence , self - regulatory efficacy , and task difficulty preference ) , 
 respectively . 
 [ results ] in the taekwondo group , the color - word and self - confidence scores 
 increased significantly after intervention as compared to those before intervention . 
 [ conclusion ] it is suggested that regular taekwondo training may be effective for 
 enhancing cognitive function and academic self - efficacy in growing children .