The purpose of the current study is to investigate the changes in physical activity (PA), sleep time (ST), and body weight (BW) Pre- and during COVID-19 in South Korea, and specifically, PA data were obtained during COVID-19 at three-time points based on the multilevel social distancing policies. All data were surveyed by questionnaires online and offline, and participants were required to fill in the monthly average of daily step counts were recorded an application on participants’ smartphone devices from Pre-COVID-19 (2019 year) and during COVID-19 (2020 year). Participants were 834 adults (males: 54.4%, female: 45.6%) and all statistical analyses were summarized by SPSS 25.0 program. The monthly average of daily step counts was 6747.09 during Pre-COVID-19, but the PA during COVID-19 was 5812.11 daily step counts per month. Also, there were significant pairwise differences between average PA Pre-COVID-19 and each level of social distancing (p < 0.001). After COVID-19, the participants who slept less than 7 h decreased by 3.6%, while those who slept more than 9 h increased by that much. As a result of BW, 269 participants responded their BW changed during COVID-19, and 199 of them reported they gained BW during COVID-19 (74.0%). Although self-reported questionnaires may have led to an under-or over-estimation of ST and BW, the present study found that the environment in which the COVID-19 is prevalent had adverse relationships on PA, ST, and BW. Therefore, it is important to identify strategies to motivate individuals for remaining physically active and getting adequate sleep while maintaining social distancing due to the presence of the COVID-19 global pandemic.

The purpose of this study is to provide essential data for the establishment of education and policy for the formation of healthy lifestyles of adolescents in the future by analyzing the patterns of changes in society due to the prolonged COVID-19 in the physical activities, sleeping habits, obesity, and mental health of Korean adolescents. To this end, a total of 147,346 adolescents were selected and analyzed according to the purpose of the study in the 2018 (14th), 2019 (15th), and 2020 (16th) raw data of the “Youth Health Behavior Online Survey,” an annual national approval statistical survey conducted by a Korean government agency. The study examined changes in the physical activity, obesity, sleep, and mental health of Korean adolescents due to COVID-19. The physical activity rate of Korean adolescents in 2019 decreased by 5.3% from 2018. In addition, the physical activity rate in 2020 decreased by 2.1% compared to 2019. It was found that physical activity steadily decreased (p < 0.001). The obesity rate increased by 0.9% in 2019 compared to 2018 and by 1.8% in 2020 compared to 2019. Although the obesity rate steadily increased, it was found that it was accelerated due to COVID-19 (p < 0.001). Looking at the subjective sleep satisfaction rate of Korean adolescents, in 2019, it was 0.1% lower than in 2018, while in 2020, when COVID-19 began, it increased by 3.5% compared to 2019. It was found that satisfaction with sleep increased after COVID-19. Finally, the mental health characteristics of Korean adolescents by year were divided into stress and depression. Stress decreased by 1% compared to 2019 and 2018 and by 6.2% compared to 2020 and 2019. Depression increased by 1% in 2019 compared to 2018 and decreased by 3.4% in 2020 compared to 2019. In other words, stress and depression decreased after COVID-19. In 2020, when COVID-19 occurred, it was confirmed that there was a change in the health behavior of adolescents compared to 2018 and 2019. Therefore, active responses from schools, families, and communities are required to foster healthy lifestyle habits in social changes such as COVID-19.

The current study is to examine the differences in physical activity (PA), sedentary behavior (SB), and mental health (i.e., stress, depression, and suicidal behaviors) between early menopausal women and age-matched general middle-aged women. Among 1348 participants in South Korea, 674 participants who experienced menopause before the age of 45 were defined as the early menopausal group, and 674 women who experienced menopause from 45 years to 55 years were classified as the general group by matching age based on early menopausal women. PA, SB, and mental health were evaluated by using the Global Physical Activity Questionnaire (GPAQ). An independent t-test was used to compare the associations of PA, SB, and mental health between the two groups. To demonstrate the predictors of early menopause, variables in the study were analyzed by multinomial logistic regression. The main findings were that moderate-to-vigorous PA (MVPA) and light PA (LPA) had significant differences between the two groups, but SB had no significant differences. In mental health, only perceived stress had significant differences in this study. The moderate level of stress in the early menopausal group was twice as high as that of the general group, and the severe level of stress was even 2.6 times higher than the general group. PA plays an essential role in mitigating the causes of mortality and the risk of various chronic diseases and improving quality of life; thus, the main findings of this study could be important to provide insights on the corresponding impact between early menopausal women and PA to encourage their healthy lifestyle. Further longitudinal studies are needed to examine the mechanisms underlying the effects of PA, SB, and mental health on early menopausal women.

The present study examines the association between physical activity (PA) participation modes (i.e., family, friends, club members, and alone), PA volumes (i.e., intensity and duration), gender, and injury. A total of 9000 Koreans aged 10–89 years participated in the Korean Survey of Citizens’ Sports Participation project. However, participants who did not respond to a question regarding PA participation modes (n = 2429) and those under 18 years old (n = 489) were excluded from this study. Analysis of variance (ANOVA) was used to compare the groups’ characteristics and the association between PA participation modes and injury was demonstrated by conducting multinomial logistic regression analysis. The risk of injury was significantly higher in the friend and club member groups than in the alone group. In addition, PA intensity and gender were critical risk factors of injury, while PA duration showed no significant results. The results indicated a strong association between PA participation modes, PA intensity, gender, and injury, and an interesting finding is that more injuries derived from a higher intensity of PA, not from a longer duration of PA. Therefore, this present study directly documented that considerable attention should be placed on the factors that affect injuries, such as gender and PA intensity, to prevent unpredictable injury and encourage potential participants to exercise with diverse participation modes and appropriate intensity.

This study used netnography and interviews to explore the sociocultural significance of South Korean sports stars’ impression management using social media. The study investigated Instagram, a widely used image-based social media platform. Through netnography, the study analysed Instagram content, and then it conducted interviews with stars for deeper interpretation. The results showed that the impression management strategies used are multifaceted. Some stars use social media to maintain personal connections, through which they create intimacy by sharing details from their daily lives and engaging in ‘self-expression’ to empathize with and relate to fans, which in turn helps them promote sponsored products or companies. Others intentionally create distance by uploading posts related to their economic and sociocultural capital. Sports stars also engage in ‘role model’ and ‘modesty’ strategies by presenting themselves as good examples on and off the field and uploading posts that promote their humility, appealing to South Korean social values.

The purpose of the present cross-sectional study was to examine the impacts of allergic respiratory diseases on physical activity (PA), sedentary behaviors (SB), and body mass index (BMI) by matching age and gender with those adolescents without allergic respiratory diseases. This present study analyzed data from the 2019 Korea Youth Risk Behavior Web-based Survey (KYRBWS). Among 57,303 Korean adolescents who responded to the survey, the study divided adolescents into three different groups (i.e., general, asthma, and allergic rhinitis group). Asthma and allergic rhinitis groups included adolescents who checked on asthma- or allergic rhinitis-related questions as ‘yes’ (n = 259, n = 259), but the general group responded to any diseases-related question as ‘no’ (n = 259). The age and gender of participants among the three groups were matched. The results showed weight and BMI were significantly higher in asthma and allergic rhinitis groups compared to the general group (p < 0.001, p < 0.001). Furthermore, age, asthma, and allergic rhinitis were observed to be strong risk factors for predicting obesity in adolescents (BMI, >25.0 kg/m²). In addition, this study found allergic respiratory diseases strong impacts on BMI levels because adolescents with ongoing asthma, or allergic rhinitis symptoms were more likely to have the inevitability of further weight gain compared to the general adolescents. Therefore, not only national interest in adolescents with allergic respiratory disease is essential, but PA should be encouraged to prevent and alleviate these diseases due to obesity.