Taekwondo is a Korean martial art and international sport, and its psychosocial benefits for its trainees have been studied extensively. This review aims to systematically assess and meta-analyze the effects of Taekwondo training on sociality, character, etiquette, and school life adjustment. We searched the RISS, NDSL, and KISS electronic databases between January 1985 and December 2019. We also included gray literature, such as theses, in addition to peer-reviewed articles. R software (version 3.6.2, R Core Team, Vienna, Austria) was used to synthesize the effect sizes and perform moderation analyses. Twenty-eight studies (24 cross-sectional and four intervention studies) were included in the final meta-analysis. Significant positive effects of Taekwondo training were found on sociality (MD = 0.266, 95% CI: 0.191 to 0.341), character (MD = 0.446, 95% CI: 0.331–0.560), etiquette (MD = 0.562, 95% CI: 0.500–0.624), and school life adjustment (MD = 0.308, 95% CI: 0.195–0.421). Overall, the findings of this meta-analysis support that Taekwondo can have a positive impact on the psychosocial factors of trainees. Due to several limitations discussed, well-designed RCTs and multiple levels of Taekwondo intervention studies should be conducted in future research to validate the current findings.

The purpose of this study is to confirm the health behavior performance rate and cardiovascular disease-related indicators according to the subjective health perception of prediabetic and diabetic patients using the 2016–2019 National Health and Nutrition Examination Survey (NHANES) data. This study classified hemoglobin A1c ≥ 6.5% as diabetes and 5.7–6.4% prediabetes among 2485 adults over 40 years of age among the data from the National Health and Nutrition Examination Survey. In addition, subjective health perception was divided into ‘good’ and ‘bad’ and then cross-classified into four groups (Good/PDM, Bad/PDM, Good/DM, and Bad/DM) to analyze the differences between the four groups. All statistical analyses were performed using SAS 9.4 (SAS Institute Inc., Cary, NC, USA), and complex sample analysis was performed using weights according to the KNHANES raw data usage guidelines from the Korea Centers for Disease Control and Prevention. The rate of subjective health awareness was higher in men than in women in both prediabetic- and diabetic-stage subjects and adults in the prediabetic stage were higher than in the elderly. The better the subjective health status, the higher the ratio of normal weight, proper sleep time, exercise, and eating out among health-related behaviors. As a result of analyzing blood pressure and blood indices related to the cardiovascular disease risk (Framingham Risk Score), in all indicators except blood pressure, the better the subjective health status and the lower the risk of cardiovascular disease. As a result, for disease prevention and continuous management through healthy behaviors in prediabetic and diabetic patients, it is necessary to improve the positive subjective perception of health.

Background: The purpose of this study is to investigate the effect of Taekwondo training on body composition and to evaluate the magnitude of the effect. Methods: Databases were used to select studies related to the effectiveness of Taekwondo training, and the inclusion criteria were as follows. Results: Thirty-seven studies were selected. We found statistically significant differences from the control group in weight, body mass index (BMI), waist circumference (WC), waist–hip ratio (WHR), body fat mass, body fat percentage, lean mass, and muscle mass. Also, the age group was statistically significant in control variables on weight, BMI, and body fat percentage. Conclusions: Taekwondo training had a positive effect on body composition, and these results suggest that Taekwondo training is an effective exercise method to lower obesity.

It is most important to reach the maximum bone density in the childhood period to prevent developing osteoporosis; it is widely known that increased body weight has a positive correlation with bone density and that even though both the fat mass and lean mass have a significant impact on bone density, the latter mass has more importance for adults. Therefore, the study analyzed to identify the relationship between bone density and both fat mass and lean mass of Korean adolescents. Subjects were chosen among 21,303 people from the Korea National Health and Nutrition Examination Survey (KNHNES) between 2008 and 2011 that took a bone density checkup; as a result, 1454 teenagers aged between 12 and 18 were selected. Data analysis was performed in SAS ver. 9.4 (SAS Institute Inc., Cary, NC, USA) following the KNHNES and the weighted complex sample analysis was conducted; body fat mass and lean mass were divided into quintile groups, and to figure out the differences in bone density that were analyzed in six models adjusted by body weight (kg) and walking (yes/no), muscle strengthening exercises (yes/no), nutrition (intake of ca (g), and serum vitamin D (ng/mL)). Then, the generalized linear model (GLM) and trend test were conducted for each gender with a significance level of 0.05. The bone density differences of fat mass and lean mass were analyzed. The result of Model 6 considering all correction variables is as follows; in the case of male adolescents, the total femur and lumbar spine showed a significant difference (F = 13.120, p < 0.001; F = 12.900, p < 0.001) for fat mass, and the trend test showed that the figures significantly decreased (β = −0.030, p < 0.001; −0.035, p < 0.001). Meanwhile, for lean mass, the total femur and lumbar spine had a significant difference (F = 16.740, p < 0.001; F = 20.590, p < 0.001) too, but the trend test showed a significant increase (β = 0.054, p < 0.001; 0.057, p < 0.001). In the case of female adolescents, the lumbar spine (F = 3.600, p < 0.05) for lean mass showed a significant difference, and it also significantly rose in the trend test too (β = 0.020, p < 0.01). To sum up the results, for male adolescents, the bone density differences for fat mass (FM) and lean mass (LM) all had significant differences, but for female adolescents, only the lumbar spine for LM showed such a result. Meanwhile, both genders showed that LM had a more positive impact on bone density than FM.

The purpose of this study is to examine changes in physical activity in Korean society, after the outbreak of COVID-19. Method This study was conducted using the Korean Community Health Survey conducted in 2019 and 2020. Subjects that have been diagnosed with hypertension and diabetes were excluded; a total of 355,914 cases were involved for analysis. In terms of the analysis method, General Linear Model (GLM) was conducted to examine the changes in physical activities in 2019 and 2020 depending on the presence of a spouse, educational status, and economic activities. In addition, the GLM was adopted to divide the subjects by gender and age, and analyze their physical activity changes in 2019 and 2020 with spouse presence, educational status, and economic activities as adjusted variables. Result In terms of Koreans, those without a spouse, high educational attainment, and economically inactive were less engaged in physical activities. Differences were found in subjects regarding moderate-intensity physical activities after social distancing following the spread of COVID-19. Senior females without a spouse, both males and females with low educational attainment, economically inactive adult females, and economically active senior males showed a greater drop in physical activities. For walking hours, both adult males and females without a spouse, adult females with all educational attainment level excluding elementary and middle school graduates, and economically inactive adult males and females also showed a downward trend. Conclusion The study recommends that people develop a strategy to increase their post-outbreak physical activity, taking into account the sociodemographic.

The tendency of misperceiving one’s body image was found to be higher among those at normal body mass index (BMI). Thus, the present study aims to provide basic data to seek solutions for ideal physical activities and right body image perception by comparing health-related behaviors of women at normal BMI. Among the 39,225 respondents from the Korea National Health and Nutrition Examination Survey (KNHNES) conducted from 2013 to 2017, 10,798 adult women with World Health Organization (WHO) BMI Classifications of 18.5 ≤ BMI < 25 (Asia-Pacific) were considered, from which pregnant and breast-feeding women and women whose body image perception was not identified were excluded, leading to a total of 9288 women. Data were analyzed utilizing SAS ver. 9.4 for frequency analysis, cross tabulation, GLM (generalized linear model), and logistic regression analysis with complex samples design, in conformity with the guidelines of the KNHNES. The results showed that approximately most (87.6%) of adult Korean women misperceived their body image. Misperception of body image was related to inappropriate health-related behaviors such as smoking, insufficient sleeping, and excessive body weight management; those who had underestimated their body image (≤64 odds ratio (OR) (0.718 (confidence interval (C.I.) 0.594–0.866))) carried out fewer health-related behaviors, while women aged 65 or above engaged in more health-related behaviors when they perceived themselves as obese (OR 1.683 (C.I. 1.260–2.248; overestimation)). To sum up, it was found that lack of health management, inappropriate body weight control, and health-related behaviors are related to body image misperception compared with real BMI. As such, it is necessary to have educational programs to encourage building proper perception of one’s body image and body weight, and to carry out health-related behaviors.