Composition of weekly physical activity in adolescents by level of physical activity

Influence of Body Mass Index, Physical Fitness, and Physical Activity on Energy Expenditure during Recess

This study aims to investigate the potential relationship between energy expenditure, physical fitness level, physical activity, and body mass index among children taking part in a 30 min school recess. A total of 259 participants from three schools were included in this study. Data on energy expenditure during recess, age, gender, anthropometric measurements, global physical fitness, and physical activity index were recorded. The evaluation sessions occurred twice a week on alternate days over two weeks. A significant gender difference was observed in energy expenditure during recess, favoring boys (p < 0.01). The participants classified as very active exhibited significantly higher scores compared to those categorized as sedentary and moderately active, respectively (p < 0.01), with a poor but significant correlation (rho: 0.208; p < 0.001). There were significant differences between energy expenditure and cardiorespiratory fitness and energy expenditure and global physical fitness (p < 0.01) with fair (rho: 0.289; p < 0.001) and poor (rho: 0.196, p = 0.001) correlation, respectively. In contrast, there were no significant differences by body mass index categories (p = 0.571). These results suggest that gender, physical activity index, and global physical fitness were found to influence energy expenditure during a 30 min recess. However, no significant relationships were found with the body mass index.

Normative-referenced values for health-related fitness among Czech youth: Physical fitness data from the study IPEN Adolescent Czech Republic

OBJECTIVES

The aim of this study was to developed sex- and age-specific normative-referenced percentile values for health-related fitness among 12 to 18 years old Czech youth.

METHODS

This study included cross-sectional data from 1,173 participants (50.7% boys) collected between 2013 and 2016. Participants were recruited from 32 elementary or secondary schools across eight cities located in the Czech Republic. Health-related fitness was objectively measured using both anthropometric (height, body mass, and sum of skinfolds) and performance (20-m shuttle run for cardiorespiratory endurance, modified push-ups for muscular strength/endurance, and V sit-and-reach for flexibility) tests. Sex- and age-specific normative values were calculated using the Lambda Mu Sigma method. Sex- and age-related differences in means were expressed as standardized effect sizes.

RESULTS

Normative percentiles were tabulated and displayed as smoothed curves. Among boys, measures of health-related fitness generally increased with age, except for an age-related decline in the sum of skinfolds and a plateau in V sit-and-reach. Among girls, most measures of health-related fitness increased from age 12 to 16 years before stabilizing, except for the sum of skinfolds, which remained stable from age 12 to 18 years. The sex-related differences were large with boys having higher cardiorespiratory endurance and muscular strength/endurance than girls. Girls compared to boys had higher flexibility.

CONCLUSIONS

This study presents the most up-to-date sex- and age-specific normative-referenced percentile values for health-related fitness among Czech youth. Normative values may be useful for fitness and public health screening and surveillance, for example, by helping to identify youth with low fitness who might benefit from a fitness-enhancing intervention.

Quantification of the Number of Steps in a School Recess by Means of Smart Bands: Proposal of Referential Values for Children and Adolescents

(1) Background: Regular physical activity has multiple benefits. Therefore, school recess is a key tool to provide opportunities for schoolchildren to engage in extracurricular physical activity, have fun, play and interact with their peers. The aim is to provide reference data to quantify the number of steps that children and adolescents perform in a school recess using smart bands according to age range and sex. (2) Method: A descriptive cross-sectional study was carried out in 494 schoolchildren aged 6 to 17 years (292 males and 202 females). Weight, standing height and waist circumference (WC) were evaluated. The body mass index (BMI) was calculated. The quantification of the number of steps during school recess was performed using a smart band. (3) Results: Percentiles were constructed for the number of steps (number of steps/recess). The cut-off points considered were <p25 (below average), p25 to p75 (average) and >p75 (above average). The median values in both sexes decreased as the age range increased. Youth who walked fewer steps during recess (<p25: below average) had elevated BMI and WC values relative to those who walked within average and above average. (4) Conclusion: The number of steps taken by schoolchildren during school recess decreases drastically with advancing age. The proposed reference values can be used to categorize schoolchildren according to the number of steps taken and to compare them among their peers. The results suggest their use and application in schools as a way of achieving the minimum physical activity recommendations.

The Relationships between Physical Activity, Screen Time and Sleep Time According to the Adolescents' Sex and the Day of the Week

This study had two aims: (1) to identify the levels of physical activity, screen time and sleep time of adolescents according to the sex of the participant and the day of the week; (2) to find out the relationships between physical activity, screen time and sleep time according to the sex of the participant and the day of the week. The study design was non-experimental, descriptive-correlational and cross-sectional. The sample consisted of 694 adolescents in Compulsory Secondary Education from Soria (Spain). Four by One-Day Physical Activity Questionnaires were used to measure levels of physical activity, screen time and sleep time. Levene’s test and Student’s t-test were used to calculate the difference between the means of the variables. Pearson’s test was used to calculate bivariate correlations between variables. Results showed higher levels of screen time in males (136.93 min/day ± 81.548). Screen time, sleep time and moderate−vigorous physical activity are higher during the weekend. Positive relationships were found between screen time and light physical activity (rmales = 0.274; p ≤ 0.01; rfemales = 0.065; p > 0.05). The correlations between moderate−vigorous physical activity and screen time were negative (rmales = −0.282; p ≤ 0.01; rfemales = −0.187; p ≤ 0.05). The relationship between screen time and sleep time was negative in males (r = −0.135; p ≤ 0.05). In conclusion, the levels of physical activity, screen time and sleep time vary according to the sex of the participants and the day of the week.

Time Trends of Step-Determined Physical Activity Among Adolescents With Different Activity Levels in Czech Republic

BACKGROUND

This study aimed to present step-determined physical activity trends in adolescents with different activity levels over a period of 10 years.

METHODS

Pedometers were used to monitor weekly physical activity in 1855 boys and 2648 girls aged 15-19 years recruited from 155 schools in the Czech Republic between 2009 and 2018. Trends for average steps/day and percent of accumulating various levels of steps/day (<10,000, 10,000-13,000, and >13,000 steps/d) were analyzed by sex.

RESULTS

There was a statistically significant decrease in average steps/day between 2009-2010 and 2017-2018 in boys from 12,355 (3936) steps/d to 10,054 (3730) steps/d and girls from 11,501 (3278) steps/d to 10,216 (3288) steps/d. The percent accumulating <10,000 steps/d increased by 21% in boys and 12% in girls. The percent achieving >13,000 steps/d decreased by 17% in boys and 10% in girls.

CONCLUSIONS

Objectively collected evidence indicates an overall decrease in Czech adolescents' steps/day over a 10-year period concurrent with an increase in the percent of boys and girls accumulating <10,000 steps/d. These trends are concerning as they portend a decline in physical activity as adolescents transition to adulthood and continue to age, which also may have major health implications.

The CLOCK 3111T/C polymorphism is associated with hour-by-hour physical activity levels only on weekends among Japanese male and female university students

BACKGROUND

CLOCK 3111T/C has been shown to be closely associated with morningness-eveningness, such as sleep-wake rhythms in healthy humans. However, previous studies examined the physical activity (PA) in a single day, and no study has investigated the relationships between CLOCK 3111T/C polymorphism and PA for an entire week. It was hypothesized that the CLOCK 3111T/C polymorphism might be associated with diurnal PA patterns, especially on the weekends.

METHODS

Eighty-one university students (male, n=14; female, n=67; age, 20.4±2.9 years) wore a digital accelerometer for 7 successive days, including the weekend, to collect hour-by-hour objectively-measured PA. CLOCK 3111T/C polymorphism was assessed using the oral mucosa. During the study, participants recorded their wake time and bedtime each day. Furthermore, lifestyle-related variables (i.e. morningness-eveningness, habitual meal and sleep timings) were collected using questionnaires. Linear mixed-effects models assessed the association of polymorphism (TT carriers vs. TC+CC carriers) with wake time and bedtime as well as daily PA throughout the week (time).

RESULTS

TT carriers had an earlier wake time (weekly mean: 44 min [95% CI, -82 to -5 min], time interaction: p=0.026) and bedtime (weekly mean: 30 min [95% CI, -61 min to - 15 sec], time interaction: p=0.048) than TC+CC carriers. Furthermore, TT carriers' wake time and bedtime on Saturday were significantly later than on other days (gene interaction: all p<0.05). On Saturday, the hour-by-hour PA in TT carriers was significantly greater than that in TC+CC carriers (hourly mean 1.7 min [95% CI, 0.2 to 3.4 min], time: p<0.001, group: p=0.028, interaction: p=0.155).

CONCLUSIONS

CLOCK 3111T/C polymorphism may be associated with objectively measured hour-by-hour PA only on Saturday. Academic/social obligations may mask the genetically determined biological rhythm of PA on weekdays.

On the issue of continuity in the formation of universal competencies among school graduates and university students

In recent years, the issues of preserving the health of the population and prevention of certain diseases leading to a significant deterioration in the life quality and human activity have been keenly discussed all over the world. This circumstance has significantly activated the scientific research in development and testing of educational programs, which are based on the development of the need for systematic independent physical exercises that contribute to the formation of general cultural competencies among students of educational institutions. At the same time, the level of formation of this knowledge, skills and abilities should contribute to the further continuous process of formation of universal competencies in physical culture and sports of university students. This paper aims to analyze and experimentally substantiate the need for continuity in the formation of universal competencies among schoolchildren and university students in physical culture, as the basis for successful professionally applied physical training of future specialists in various fields of economics. The conducted research shows the need to improve the organizational and content provision of physical culture in general education institutions to increase the effectiveness of organized physical culture classes, and to improve the quality of the formation of general cultural competencies (knowledge, skills, abilities).

Structural Relationship between Korean Adolescent's Sports Participation, Optimism, Pessimism, Self-Regulation, and Coronavirus-Related Stress in the Pandemic Situation

This study aimed to examine the relationships between sports participation, optimism/pessimism, self-regulation, and coronavirus-related stress in Korean adolescents during the pandemic situation. Specifically, we attempted to offer valuable information that could help to alleviate coronavirus-related stress in adolescents by promoting participation in sports and the development of optimism and self-regulation. To achieve this aim, we conducted an online survey of 836 Korean adolescents in the pilot and main studies. Confirmatory factor, frequency, path, reliability, descriptive statistical, and multimedia analyses were performed. Our findings indicated several differences for each variable according to demographic characteristics. Sports participation exerted a positive effect on optimism (p < 0.001) and self-regulation (p < 0.01) and negative effects on coronavirus-related stress (p < 0.05) and pessimism (p < 0.001). In addition, optimism exerted a positive effect on self-regulation (p < 0.001) and a negative effect on coronavirus-related stress (p < 0.001), while pessimism exerted a negative effect on self-regulation (p < 0.01) and a positive effect on coronavirus-related stress (p < 0.001). Further analysis indicated that self-regulation had a negative effect on coronavirus-related stress (p < 0.05). These findings highlight the need for youth educational institutions to encourage adolescents to participate in sports and for organizing bodies to suggest various policies and provide education that can assist them in properly coping with and overcoming coronavirus-related stress by strengthening their optimistic attitude and self-regulation ability.

Relationships among the Degree of Participation in Physical Activity, Self-Concept Clarity, and COVID-19 Stress in Adolescents

The COVID-19 pandemic situation threatens the health of people globally, especially adolescents facing mental problems such as depression, anxiety, and obsessive-compulsive disorder due to constant COVID-19 stress. The present study aimed to provide basic data highlighting the need to alleviate COVID-19 stress among adolescents by promoting physical activity participation and strengthening self-concept clarity (SCC). To examine the relationships among participation in physical activity, SCC, and COVID-19 stress in pandemic-like conditions, the study was conducted on middle and high school students aged 14 to 19 and an online survey was conducted on 1046 Korean adolescents (521 male and 525 female students in the preliminary survey and main survey). Frequency, reliability, confirmatory factor, descriptive, and path analyses were performed using SPSS and AMOS 18.0. Participation in physical activity exerted a positive effect on SCC (p < 0.001) as well as a negative effect on COVID-19 stress (p = 0.031). Our findings also indicated that SCC exerted a negative effect on COVID-19 stress (p < 0.001). Regular participation in physical activity and strong SCC are also fundamental elements for alleviating COVID-19 stress. Given these results, state and local governments and educational institutions should encourage youth to participate in sports by suggesting policies, providing guidelines, and offering education. Such information may allow adolescents to endure and overcome COVID-19 stress during this critical period of life.

The Relationship between Korean Adolescents' Sports Participation, Internal Health Locus of Control, and Wellness during COVID-19

This study was aimed at providing practical information to improve Korean adolescents' wellness by empirically identifying its correlation with sports participation and having an internal health locus of control (IHLC) during the COVID-19 pandemic. This study comprised both a pilot test and a main study. We recruited 844 Korean adolescents as subjects in January 2021 to participate in an online self-reported survey. The reliability and validity of the scales used (sports participation, IHLC, and wellness) were verified through a pilot test. In the main study, we verified the differences between all variables according to adolescents' demographic characteristics and the structural relationship of sports participation, IHLC, and wellness. Sports participation had a positive effect on IHLC (p < 0.001) and wellness (p < 0.001). Additionally, IHLC had a positive effect on wellness (p < 0.001). In juvenile educational institutions, there is a need to develop strategies to increase wellness, sports participation, and IHLC among adolescent students, which can improve their wellness in the context of the COVID-19 pandemic.

Physical Activity Level, Mediterranean Diet Adherence, and Emotional Intelligence as a Function of Family Functioning in Elementary School Students

(1) Background: Family is considered as one of the most important elements for the transmission of healthy habits that improve the lives of students. For this reason, the present study aims to describe the degree of family functionality, emotional intelligence, Mediterranean diet adherence, and extra-curricular physical activity engagement. A further aim is to perform a correlational analysis between these variables. (2) Methods: To this end, an ad hoc questionnaire was used, alongside the APGAR, KIDMED, and Trait Meta Mood Scale (TMMS-24). (3) Results: Finally, the data suggest that a high percentage of students need to improve their diet. Further, students reporting severe family dysfunction showed worse outcomes. Thus, levels of emotional clarity were lower when family functionality was poor. Poor diet quality was also associated with lower emotional attention, with Mediterranean diet adherence being positively related to emotional clarity and repair, as well as normal family functionality. (4) Conclusions: Boys showed higher levels of adherence to the Mediterranean diet adherence, while girls reported higher family functionality. Thus, compliance with the minimum recommendations for physical activity engagement was associated with adequate adherence to the Mediterranean diet. The importance of diet for obtaining an optimal physical condition, adequate emotional state, and family functionality is highlighted.

Physical Activity Recommendations for Segments of School Days in Adolescents: Support for Health Behavior in Secondary Schools

School physical activity (PA) is an indispensable part of daily PA, the foundation for developing lifelong PA and fitness, and an easy way to gain physical and health literacy. School PA is equally important for understanding the continuity of physical and mental health, even in broader psychosocial aspects. Regarding long-term outcomes, significant attention has been paid to the determination of daily and weekly recommendations for adolescent PA. However, comprehensive approaches suggesting recommendations for PA in segments of the school day are rare. This study aimed to (a) provide a rationale for PA recommendations in segments of school days and incorporate it into generally accepted PA recommendations, and (b) promote radical changes in the educational process toward a healthy school lifestyle through PA recommendations in segments of school days. The results of research conducted in 98 secondary schools in the Czech Republic and 104 secondary schools in Poland from 2009 to 2017 were used in this study. In total, 3,860 boys and 5,237 girls from the Czech Republic and 3,052 boys and 3,329 girls from Poland, all aged 15-19, participated. We recommended at least 2,000 steps (or 10 min of moderate-to-vigorous PA) for the before school segment and at least 6,000 steps (or 30 min of moderate-to-vigorous PA) for the after-school segment. For the time spent at school, we further recommended at least 500 steps/h (alternatively, at least 3,000 steps/school time), 20 min of moderate-to-vigorous PA (≥3METs or 60% HRmax), and at least one HRsubmax/max response to significant stress during PA to mitigate educational stress and high levels of sedentary behavior in schools. PA should account for at least 25% of school time, even on days with no scheduled physical education lessons. We propose using PA recommendations in segments of school days to achieve positive changes in the educational process and school lifestyle. Acceptance of PA recommendations in segments of school days theories on physical education could help refine and concretize demands for changes in PA and lifestyle in secondary schools. In practice, it could support the creation of innovative and comprehensive school PA programs. Future research should focus on obtaining evidence in support for adolescent PA by applying PA recommendations in segments of school days.