Association of physical activity, vitamin E levels, and total antioxidant capacity with academic performance and executive functions of adolescents

Healthy Lifestyle Related to Executive Functions in Chilean University Students: A Pilot Study

BACKGROUND

A negative lifestyle is reported to be related to cognitive problems. However, there is little information about this in relation to university students. The objective of the present study was to investigate the association between executive functions (EFs) and lifestyle parameters (i.e., physical activity (PA), sleep duration, screen time (ST), and food habits) among Chilean university students.

METHODS

This cross-sectional study included a total of 150 university students (94 females and 56 males, aged 21.28 ± 3.15 and 22.18 ± 2.90 years, respectively). Cognitive outcomes were measured using the CogniFit assessment battery. Lifestyle was measured through validated questionnaires.

RESULTS

Across the total sample, attention exhibited a positive association with PA h/week (β: 24.34 95% CI: 12.46 to 36.22, p = 0.001). Additionally, coordination was positively associated with PA h/week (β: 15.06 95% CI: 0.62 to 29.50, p < 0.041). PA h/week was positively linked with reasoning (β: 20.34 95% CI: 4.52 to 36.17, p = 0.012) and perception (β: 13.81 95% CI: 4.14 to 23.49, p = 0.005). Moreover, PA h/week was significantly linked to memory (β: 23.01 95% CI: 7.62 to 38.40, p = 0.004). In terms of the EFs, PA h/week showed a positive association with cognitive flexibility (β: 45.60 95% CI: 23.22 to 67.69, p = 0.001).

CONCLUSIONS

In conclusion, lifestyle (PA h/week) was positively associated with EFs. Therefore, an increase in PA levels among these students should be a target for community- and university-based interventions in order to promote cognitive development such as attention, coordination, reasoning, perception, memory, and cognitive flexibility.

The moderating role of recreational substance use in the association of Mediterranean diet with academic performance among adolescents

No study has examined the potential moderating role of recreational substance use in the relationship between the Mediterranean diet (MedDiet) and academic performance. The aim of this study was to test the potential moderating role of recreational substance use (i.e., alcohol, tobacco, and cannabis) in the association of adherence to the MedDiet with academic performance among adolescents. This cross-sectional study included a sample of 757 adolescents (55.6% girls) aged 12-17 years from the Valle de Ricote (Region of Murcia). The Region of Murcia is an autonomous community of Spain located in the southeast of the Iberian Peninsula, along the coast of the Mediterranean Sea. Adherence to the MedDiet was assessed by the Mediterranean Diet Quality Index for Children and Teenagers (KIDMED). Recreational substance use (i.e., tobacco, alcohol, cannabis) was self-reported by adolescents. Academic performance was assessed by the school records at the end of the academic year. The relationship between adherence to the MedDiet and academic performance was moderated by both tobacco and alcohol use (for grade point average and all school records). In conclusion, higher adherence to the MedDiet was related to greater academic performance in adolescents, but recreational substance use could moderate this association.

Effects of High-Intensity Interval Training on Melatonin Function and Cellular Lymphocyte Apoptosis in Sedentary Middle-Aged Men

Background: Physical performance increased by controlled interventions of high-intensity intermittent training (HIIT); however, little is known about their influence as anti-aging and antioxidant effects, or their role in mitochondrial biogenesis. Purpose: This study aimed to determine the effects of HIIT for 12 weeks on melatonin function, lymphocyte cell apoptosis, oxidative stress on aging, and physical performance. Methods: Eighty healthy male subjects aged 18-65 years randomly participated in a HIIT-exercise training program for 12 weeks. Anthropometric analysis, cardiovascular fitness, total antioxidant capacity (TAC), lymphocyte count and apoptosis, and serum melatonin and cytochrome c oxidase (COX), were estimated for all subjects before and after HIIT-exercise training. HIIT training was performed in subjects for 12 weeks. Results: Data analysis showed a significant increase in the expression levels of the melatonin hormone (11.2 ± 2.3, p < 0.001), TAC (48.7 ± 7.1, p < 0.002), COX (3.7 ± 0.75, p < 0.001), and a higher percentage of lymphocyte apoptosis (5.2 ± 0.31, p < 0.003). In addition, there was an improvement in fitness scores (W; 196.5 ± 4.6, VO₂max; 58.9 ± 2.5, p < 0.001), adiposity markers (p < 0.001); BMI, WHtR, and glycemic control parameters (p < 0.01); FG, HbA1c (%), FI, and serum C-peptide were significantly improved following HIIT intervention. Both melatonin and lymphocyte apoptosis significantly correlated with the studied parameters, especially TAC and COX. Furthermore, the correlation of lymphocyte apoptosis with longer exercise duration was significantly associated with increased serum melatonin following exercise training. This association supports the mechanistic role of melatonin in promoting lymphocyte apoptosis either via the extrinsic mediator pathway or via inhibition of lymphocyte division in the thymus and lymph nodes. Additionally, the correlation between melatonin, lymphocyte apoptosis, TAC, and COX activities significantly supports their role in enhancing physical performance. Conclusions: The main findings of this study were that HIIT exercise training for 12 weeks significantly improved adiposity markers, glycemic control parameters, and physical performance of sedentary older adult men. In addition, melatonin secretion, % of lymphocyte apoptosis, COX activities, and TAC as biological aging markers were significantly increased following HIIT exercise training interventions for 12 weeks. The use of HIIT exercise was effective in improving biological aging, which is adequate for supporting chronological age, especially regarding aging problems. However, subsequent studies are required with long-term follow-up to consider HIIT as a modulator for several cardiometabolic health problems in older individuals with obesity.

The impact of the covid-19 pandemic on lifestyle behaviors in U.S. college students

OBJECTIVE

To investigate COVID-19's impact on college student health behaviors.

PARTICIPANTS

189 college students.

METHODS

Participants completed an online survey on behaviors relating to sleep, sedentary activities, and physical activity before and during the COVID-19 pandemic. Comparisons utilized Students' dependent t-test or Wilcoxon signed-rank tests.

RESULTS

There was an increase in time to fall asleep (before: 23.4 ± 18.0 vs. during: 42.8 ± 44.3 min·day^-1, p < 0.001), time spent in bed (before: 7.8 ± 1.5 vs. during: 8.5 ± 1.5 hr·day^-1, p < 0.001), as well as shifts in later bed and awake time (p < 0.001). Total sedentary time increased during the pandemic (before: 9.0 ± 3.8 vs. during: 9.9 ± 4.1 hr·day^-1, p = 0.016); and time spent using a TV, computer, or phone (before: 3.1 ± 1.9 vs. during: 4.2 ± 2.3 hr·day^-1, p < 0.001). There was a significant decrease in moderate-vigorous activity (before: 123.8 ± 96.0 vs. during: 108.9 ± 75.5 min·week^-1, p = 0.028) and resistance training days (before: 2.4 ± 2.1 vs. during: 1.7 ± 2.1 days·week^-1, p < 0.001).

CONCLUSIONS

COVID-19 negatively influenced health behaviors in college students.

Effects of gypenoside L-containing Gynostemma pentaphyllum extract on fatigue and physical performance: A double-blind, placebo-controlled, randomized trial

This study was conducted to investigate the effect of Gynostemma pentaphyllum extract containing gypenoside L (GPE) on improving the cognitive aspects of fatigue and performance of the motor system. One hundred healthy Korean adults aged 19-60 years were randomized to the treatment (GPE for 12 weeks) and control groups, and efficacy and safety-related parameters were compared between the two groups. Maximal oxygen consumption (VO₂ max) and O₂ pulse were significantly higher in the treatment group than in the control group (p = 0.007 and p = 0.047, respectively). After 12 weeks, the treatment group showed significant changes such as decreases in the levels of free fatty acids (p = 0.042). In addition, there were significant differences in the rating of perceived exertion (RPE) (p < 0.05) and value of temporal fatigue between the treatment and control groups on the multidimensional fatigue scale (p < 0.05). Moreover, the level of endothelial nitric oxide synthase (eNOS) in the blood was significantly higher in the treatment group than in the control group (p = 0.047). In summary, oral administration of GPE has a positive effect on resistance to exercise-induced physical and mental fatigue.

Nut consumption and academic performance among adolescents: the EHDLA study

PURPOSE

The aim of this study was to examine the relationship between nut consumption and academic performance in Spanish adolescents and to explore the role of sociodemographic, anthropometric, and lifestyle covariates on this association.

METHODS

A cross-sectional study was carried out using a food frequency questionnaire for estimating nut consumption in the number of 20-30 g servings per week, and academic performance data were obtained from school records. Analyses of covariance were adjusted for sociodemographic, anthropometric and lifestyle covariates, including total energy intake.

RESULTS

Among the 846 adolescents included in the analyses (55.3% girls, age range from 12 to 17 years), the mean ± standard deviation consumption of nuts was 2.7 ± 2.8 servings per week, while the mean of all school grades recorded was 6.5 ± 2.0. Furthermore, compared to no consumption, the consumption of ≥ 3 nut servings per week was consistently associated with higher grades in language (p for trend = 0.005), combination of language and math (p for trend = 0.026), grade point average (p for trend = 0.039), and combination of all school records (p for trend = 0.046). These associations were observed regardless of all covariates considered, although sex and socioeconomic level played a significant role in the completely adjusted models.

CONCLUSION

Nut consumption is associated with higher academic performance in a representative sample of Spanish adolescents. These cross-sectional results should be confirmed in longitudinal and intervention studies.

Correlation of Percentage Body Fat, Waist Circumference and Waist-to-Hip Ratio with Abdominal Muscle Strength

Sedentary lifestyle and consumption of high-fat foods have become widespread, especially in the urban population. This leads to a reduction in lean body mass and increased body fat. The correlation between body fat indices and low back pain has been less explored and documented. The aim of this study was to identify the correlation between the percentage of body fat, waist circumference and waist-to-hip ratio and abdominal muscle strength. Percentage of body fat was estimated by using the body composition analyzer method using Tanita BC-545 Innerscan Segmental Body Composition. Waist-to-hip ratio was calculated by dividing the waist circumference by hip circumference. Abdominal muscle (rectus abdominis and external oblique) strength was measured by maximum voluntary isometric contraction as measured by surface electromyography. A positive correlation was observed between waist circumference and the percentage of body fat, while a negative correlation was observed between the average maximum voluntary isometric contraction of rectus abdominis and external oblique muscles and the percentage of body fat. Individuals with a high percentage of body fat tend to have higher fat distribution over the abdominal region and decreased abdominal muscle strength. Therapists should emphasize the use of abdominal muscles in individuals with high body fat in order to reduce the associated risk of the development of poor posture and low back pain.

Fat-soluble vitamins: updated review of their role and orchestration in human nutrition throughout life cycle with sex differences

Age and Gender are vital determinants for the micronutrient demands of normal indviduals. Among these micronutrients are vitamins that are required in small amounts for optimum metabolism, homeostasis, and a healthy lifestyle, acting as coenzymes in several biochemical reactions. The majority of previous studies have examined such issues that relates to a specific vitamin or life stage, with the majority merely reporting the effect of either excess or deficiency. Vitamins are classified into water-soluble and fat-soluble components. The fat-soluble vitamins include vitamins (A, D, E, and K). Fat-soluble vitamins were found to have an indisputable role in an array of physiological processes such as immune regulation, vision, bone and mental health. Nonetheless, the fat-soluble vitamins are now considered a prophylactic measurement for a multitude of diseases such as autism, rickets disease, gestational diabetes, and asthma. Herein, in this review, a deep insight into the orchestration of the four different fat-soluble vitamins requirements is presented for the first time across the human life cycle beginning from fertility, pregnancy, adulthood, and senility with an extensive assessment ofthe interactions among them and their underlying mechanistic actions. The influence of sex for each vitamin is also presented at each life stage to highlight the different daily requirements and effects.

Association Between Eating Habits and Perceived School Performance: A Cross-Sectional Study Among 46,455 Adolescents From 42 Countries

PURPOSE

This study analyzed the association between selected self-reported eating habits and perceived school performance in adolescents by gender.

METHODS

A cross-sectional analysis was conducted with data from a large representative sample of adolescents from 42 different countries. Participants answered questions about their weekly frequency of fruit, vegetable, sweets, and soft drink consumption, as well as the frequency of breakfast consumption and family meals. The adolescents subjectively rated their school performance compared to that of their classmates. Logistic regression models were adjusted for region, age, body mass index (z-score), socioeconomic status, physical activity, recreational screen time, and sleep difficulties.

RESULTS

Among the 46,455 (53.5% female, mean age of 13.7 ± 1.6 years) adolescents studied, 20.6% of males and 25.5% of females reported high perceived school performance. In the results of the fully adjusted analyses, the higher the frequency of all healthy eating habits studied, the higher the perceived school performance in both males and females. Specifically, both males and females reporting a higher frequency of fruit and vegetable consumption, a lower frequency of sweets and soft drink consumption, more frequent breakfast consumption, and more frequent family meals (breakfast and dinner) were more likely to perceive their school performance as higher compared to their classmates. In addition, having breakfast regularly on weekends and the frequency of family dinner were associated with better school performance in both males and females.

CONCLUSIONS

In summary, this study provide cross-sectional evidence on the association between healthy eating habits and perceived school performance. Considering that school performance is an indicator of healthy development in adolescence, our findings reinforce and extend the evidence on the importance of healthy eating at this stage of life.

Serum Fat-Soluble Vitamin Levels of 6,082 Minors in Zhuzhou City

OBJECTIVE

To explore the nutritional status of serum fat-soluble vitamins such as vitamin A, 25-hydroxyvitamin D, and vitamin E of minors in the Zhuzhou area to provide a scientific basis for clinical guidance to supplement fat-soluble vitamins reasonably.

METHOD

A total of 6,082 minors who underwent physical examination from January 2017 to February 2019 in the Children's Health Department of Zhuzhou Hospital affiliated with XiangYa School of Medicine of Central South University were selected as the subjects to measure the levels of serum fat-soluble vitamins A, D, and E.

RESULTS

(1) Their average levels of serum vitamin A, 25-hydroxyvitamin D, and vitamin E were (0.34 ± 0.08) mg/mL, (34.65 ± 10.24) ng/mL, and (10.11 ± 2.65) mg/mL, respectively. (2) Serum vitamin E showed a gender difference (P < 0.001). (3) The average levels of serum 25-hydroxyvitamin D and vitamin E in infancy, early childhood, preschool age, school age, and adolescence decreased gradually (P < 0.05). In contrast, the average level of serum vitamin A ranged between 0.32 mg/mL and 0.37 mg/mL. (4) The age was negatively correlated with serum 25-hydroxyvitamin D (r = -0.517, P < 0.001) and weakly negatively correlated with vitamin E (r = -0.366, P < 0.001), but weakly positively correlated with vitamin A (r = 0.269, P < 0.001).

CONCLUSION

Minors from infancy to adolescence in Zhuzhou should strengthen their supplementation of fat-soluble vitamins.

Gabr S. The Relationships of Watching Television, Computer Use, Physical Activity, and Food Preferences to Body Mass Index: Gender and Nativity Differences among Adolescents in Saudi Arabia

BACKGROUND

Adolescents and ethnic subgroups have been identified at high risks of overweight and its associated complications. Although some studies have investigated overweight, obesity, nutritional status, physical activity, and associated factors among Saudi students, no studies have examined these characteristics among non-Saudi students or compared non-Saudi to Saudi adolescent students. The objective of this study was to compare differences between Saudi and non-Saudi adolescent students regarding time spent watching television, using computers, engaging in physical activity, and their food preferences. The relationships between these lifestyle behaviors and body mass index by Saudi nativity and gender were tested.

METHODS

Students aged 12 to 18 years (n = 214) from various schools in Riyadh, Saudi Arabia, completed a self-administered questionnaire that included questions about demographic and anthropometric characteristics, daily after-school routine, physical activity, watching television, using computers, and food preferences. Non-parametric (Mann-Whitney U) tests assessed the statistical differences between Saudi and non-Saudi respondents, and males and females were separately tested.

RESULTS

Saudi boys who reported physical activity two to five times per week, the most television time, the most computer time, and the highest frequency of eating fast food and drinking soft drinks had a significantly higher mean body mass index than the non-Saudi boys in their categories. However, there were no significant differences found between the Saudi and non-Saudi girls.

CONCLUSIONS

High levels of sedentary and low levels of physical activities as well as high consumption of high-fat fast foods and high-sugar drinks threaten the health of Saudi adolescents. Cultural differences in lifestyle between Saudi and non-Saudi families should be considered when developing programs to improve knowledge, attitudes, and behaviors regarding diet quality and physical activity. The objective of this study is more important in the current situation where increased time spent on computers and mobile phones due to online teaching in schools or working from home, decreased physical activity due to precautionary lockdowns, and unchecked eating patterns while spending more time in sedentary activities in homes has become our COVID-19 pandemic lifestyle in all the age groups. A similar study should be replicated on a large scale to study the effect of this lifestyle on our lives in all the age groups.

Enjoy Carefully: The Multifaceted Role of Vitamin E in Neuro-Nutrition

Vitamin E is often associated with health benefits, such as antioxidant, anti-inflammatory and cholesterol-lowering effects. These properties make its supplementation a suitable therapeutic approach in neurodegenerative disorders, for example, Alzheimer’s or Parkinson’s disease. However, trials evaluating the effects of vitamin E supplementation are inconsistent. In randomized controlled trials, the observed associations often cannot be substantiated. This could be due to the wide variety of study designs regarding the dosage and duration of vitamin E supplementation. Furthermore, genetic variants can influence vitamin E uptake and/or metabolism, thereby distorting its overall effect. Recent studies also show adverse effects of vitamin E supplementation regarding Alzheimer’s disease due to the increased synthesis of amyloid β. These diverse effects may underline the inhomogeneous outcomes associated with its supplementation and argue for a more thoughtful usage of vitamin E. Specifically, the genetic and nutritional profile should be taken into consideration to identify suitable candidates who will benefit from supplementation. In this review, we will provide an overview of the current knowledge of vitamin E supplementation in neurodegenerative disease and give an outlook on individualized, sustainable neuro-nutrition, with a focus on vitamin E supplementation.

The Effects of Age, Biological Maturation and Sex on the Development of Executive Functions in Adolescents

The development of executive functions (EF) has been widely investigated and is associated with various domains of expertise, such as academic achievement and sports performance. Multiple factors are assumed to influence the development of EF, among them biological maturation. Currently the effect of biological maturation on EF performance is largely unexplored, in contrast to other domains like physical development or sports performance. Therefore, this study aimed (a) to explore the effect of chronological age on EF performance and (b) to investigate to what extent age-related changes found in EF are affected by biological maturation on both sexes. To this end, EF performance and degree of maturity, indexed by percentage of predicted adult height (%PAH), of 90 adolescents (11-16 years old, 54% males) were measured on three occasions in a time frame of 12 months. A Generalized Estimating Equation (GEE) approach was used to examine the association between chronological age and %PAH and the weighted sum scores for each EF component (i.e., inhibition, planning, working memory, shifting). All models were run separately for both sexes. The males' results indicated that EF performance improved with age and degree of maturity on all four components. Interaction effects between age and %PAH on inhibition showed that at a younger age, males with a higher %PAH had a lower chance of performing well on inhibition, whereas at later ages, males with a higher %PAH had a higher chance to have a good inhibition performance. For working memory, it seems that there is no maturity effect at a younger age, while at later ages, a disadvantage for later maturing peers compared to on-time and earlier maturing male adolescents emerged. Females showed slightly different results. Here, age positively influenced EF performance, whereas maturity only influenced inhibition. Interaction effects emerged for working memory only, with opposite results from the males. At younger ages, females with lower %PAH values seem to be scoring higher, whereas at later ages, no maturity effect is observed. This study is one of the first to investigate the effect of biological maturation on EF performance, and shows that distinct components of EF are influenced by maturational status, although the effects are different in both sexes. Further research is warranted to unravel the implications for maturation-driven effects on EF that might significantly affect domains of human functioning like academic achievement and social development.

Relationship between Physical Activity, Oxidative Stress, and Total Plasma Antioxidant Capacity in Spanish Children from the GENOBOX Study

The World Health Organization has recommended performing at least 60 min a day of moderate-to-vigorous physical activity (MVPA) and reducing sedentarism in children and adolescents to offer significant health benefits and mitigate health risks. Physical fitness and sports practice seem to improve oxidative stress (OS) status during childhood. However, to our knowledge, there are no data regarding the influence of objectively-measured physical activity (PA) and sedentarism on OS status in children and adolescents. The present study aimed to evaluate the influence of moderate and vigorous PA and sedentarism on OS and plasma total antioxidant capacity (TAC) in a selected Spanish population of 216 children and adolescents from the GENOBOX study. PA (light, moderate, and vigorous) and sedentarism (i.e., sedentary time (ST)) were measured by accelerometry. A Physical Activity-Sedentarism Score (PASS) was developed integrating moderate and vigorous PA and ST levels. Urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG) and isoprostane F2α (F₂-IsoPs), as markers of OS, were determined by ELISA; and TAC was estimated by colorimetry using an antioxidant kit. A higher PASS was associated with lower plasma TAC and urinary 8-OHdG and F₂-IsoPs, showing a better redox profile. Reduced OS markers (8-OHdG and F₂-IsoPs) in children with higher PASS may diminish the need of maintaining high concentrations of antioxidants in plasma during rest to achieve redox homeostasis.

Hidden Hunger of Vitamin E among Healthy College Students: A Cross- Sectional Study

BACKGROUND

College students may have a risk of fat-soluble vitamin deficiencies due to unhealthy dietary habits, especially for vitamin A and E. They are important members of the human antioxidant network; deficiencies of these vitamins may increase the risk of many critical diseases.

OBJECTIVE

The current study was undertaken to determine the status of vitamin A and E in college students.

METHODS

Healthy college students were recruited, and fasting blood samples of them were collected and used for determining serum levels of retinol and α-tocopherol by the HPLC method.

RESULTS

We found that there was no vitamin A deficiency in college students. However, vitamin E deficiency existed in 34.5% of college students, especially in males. All the students had no vitamin E adequacy. In addition, our findings showed that BMI was inversely associated with serum α-- tocopherol, but not serum retinol.

CONCLUSION

These results suggest that vitamin E deficiency in college students should be given more attention, and it is necessary to consider using vitamin E supplements.

Comparative antidandruff efficacy of plant extracts prepared from conventional and supercritical fluid extraction method and chemical profiling using GCMS

BACKGROUND

To combat dandruff associated pathogens, supercritical fluid extraction (SFE) can be used as an alternative eco-friendly technique to obtain antimicrobial plant extracts over conventional methods.

OBJECTIVES

The purpose of the study was to compare the yield and antimicrobial potential of extracts obtained by different extraction methods.

METHODS

Extraction was carried out by cold percolation method using ethyl acetate (EA) and SFE using CO₂. Antimicrobial activity was studied against dandruff causing microbes; Malassezia furfur, Propionibacterium acne, and Staphylococcus epidermidis by agar well diffusion and micro broth dilution method. Statistical evaluation was done by principal component analysis (PCA).

RESULTS

The yield was found higher in the ethyl acetate extracts. PCA indicated that among the sixteen extracts, SFE extract of Azadirachta indica leaves was the most influential with the highest F1 score and maximum antimicrobial activity. Cinnamomum zeylanicum SFE extract demonstrated the lowest MIC against P. acne and M. furfur. GC-MS analysis of A. indica extract inferred that ganoderic acid, 13,14-epoxyoleanan-3-ol acetate, henicosanal, 2-heptadecycloxirane were the major phytoconstituents whereas cinnamaldehyde, α- muurolene and caffeic acid were primarily found in cinnamon.

CONCLUSION

Bioactive compounds identified in the extracts of A. indica and C. zeylanicum can be used in natural antidandruff products.

Effect of Gender, Physical Activity and Stress-Related Hormones on Adolescent's Academic Achievements

BACKGROUND

Physical activity (PA) has been shown to develop better fitness and body function in children. Various studies have shown that as the age of students increases, its correlation with school achievement decreases. Different hormonal changes during adolescence make it difficult to adjust in his/her environment, causing stress. To the best of our knowledge, no study has studied the correlation between stress-related hormones and school performance among adolescents. This study was conducted to evaluate physical activity and stress-related hormones, cortisol and serotonin, among school adolescents aged 12-18 years old and find their association with academic achievements.

METHODS

A total of 300 students were invited to participate in this study. Physical activity of the participants was assessed in relation to the time spent performing various physical activities. End of the academic year grades were obtained from the school as a collective measure of academic achievement and executive function. The levels of cortisol and serotonin were measured using the competitive immunoassay techniques.

RESULTS

There was a significant correlation between age, gender, BMI, cortisol, serotonin, physical activity score; and academic achievement, and executive functioning among participants. Academic achievement and executive functioning scores correlated positively with gender, serotonin, physical activity score, but negatively with age, BMI and salivary cortisol. Stepwise regression analysis showed that physical activity and demographic parameters and stress-related hormones, cortisol and serotonin, explained around 61.9-77.9% of academic performance and executive functioning variation in school adolescents, especially females.

CONCLUSIONS

Optimal physical activity and release of stress-related hormones could be the determining factor for performance in school and other activities. These results should be taken into consideration while planning the school curriculum.

Differences among Saudi and Expatriate Students: Body Composition Indices, Sitting Time Associated with Media Use and Physical Activity Pattern

Background: Being overweight at a young age is a predictor of developing obesity and related complications later in adulthood, posing a high risk to public health. Various ethnic subgroups have been identified as having a higher prevalence of overweight or obese. Saudi Arabia is one of the fastest-growing economies in the world, where the expatriate population comprises 33% of its total population. The objective of this study was to investigate differences in body composition indices, sitting time associated with media use, and physical activity pattern among a sample of local and expatriate school students in Saudi Arabia. Methods: 500 students (aged 8-18 years) from various schools were invited to participate in this study. Body weight, waist circumference (WC) and height were measured using a portable digital metric scale, standard measuring tape and wall mounted tape respectively. Participants and their parents were jointly asked to report the average time that the participant spent sitting using media (watching TV, playing video games, and using the internet and other screen-based devices etc.) per day. The pattern of physical activity among participants was measured using a short form of the International Physical Activity Questionnaire (IPAQ). Basal metabolic rate (BMR) and total daily energy expenditure (TEE) were estimated from body weight, height, age, sex and physical activity, according to the Harris-Benedict equation. Results: Data from 450 (90%) of the participants were used for analysis. The mean age of the participants was 14.55 ± 1.74 years. Body mass index (BMI), WC, waist to height ratio (WHtR), BMR and TEE differed significantly among the participants. Physical fitness score negatively correlated with BMI and WC, while sitting time associated with media use positively correlated with BMI, WC, WHtR and physical fitness score, among both Saudi and expatriate participants. Conclusions: Body composition indices and sitting time associated with media use were higher among Saudi boys and expatriate girls. Expatriate boys and girls were reported to be physically more active than their Saudi counterparts. BMR and TEE were higher among expatriate boys and Saudi girls. Although this study provides useful information about the association of body composition indices, sitting time associated with media use, and physical activity pattern among local and expatriate school students in SA, similar studies involving a larger study sample, with equal gender representation, are further required to determine various factors associated with this link.

Weight Status, Physical Fitness, and Health-Related Quality of Life among Chinese Adolescents: A Cross-Sectional Study

PURPOSE

The impact of physical fitness (PF) on adolescents' health-related quality of life (HRQOL) is an important health issue in China. The purpose of this study was to identify whether body mass index (BMI), cardiorespiratory fitness (CRF), and musculoskeletal fitness (MSF) influences HRQOL among Chinese adolescents.

METHOD

The participants were 10,007 students (boys = 5276, 14.14 years ± 1.79; girls = 4829, 14.22 years ± 1.81) who were randomly selected from 30 secondary schools in Shandong, China. BMI, CRF, MSF, and HRQOL were measured and analyzed using ANCOVA and multiple regression.

RESULTS

BMI and physical fitness variables were partially associated with HRQOL in Chinese adolescents. ANCOVA showed a significant difference among BMI categories in terms of physical sense (PS), living convenience, and self-satisfaction (SS) for boys, but this difference was only seen with social activity opportunity (SAO) for girls. Multiple regression found that BMI was significantly associated with SAO. For boys, CRF was associated with the teacher and student relationship and SS, whereas MSF was only associated with PS. For girls, CRF was significantly linked with the parent and children relationship, learning capacity, and attitudes and self-perception (S-P), while MSF was associated with S-P.

CONCLUSION

Enforcing physical activity and enhancing PF will be a crucial pathway in improving adolescents' HRQOL in China.