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A multilevel analysis of individual- and school-level correlates of physical fitness in children
Annals of Human Biology
Abstract and Figures
Background: Children’s physical fitness is potentially influenced by biological, behavioural and environmental factors.
Aim: To investigate the importance of individual-level and school-level characteristics in explaining variation in children’s physical fitness.
Subjects and methods: The sample comprised 354 Portuguese children, aged 5-10 years. Physical fitness [(handgrip (HG) strength, standing long jump (SLJ), shuttle-run (SR), total physical fitness score (PFz)], gross motor coordination (GMC), and body mass index (BMI) were assessed. Moderate-to-vigorous physical activity (MVPA) was objectively monitored; birth weight and socio-economic status (SES) were obtained by questionnaire. School contexts were assessed via an objective audit. Multilevel models using the Bayesian approach were used.
Results: Age was positively associated with HG, SLJ, and PFz (p < 0.05); BMI was positively associated with HG (p < 0.05), and GMC with all physical fitness components (p < 0.05); MVPA was only associated with PFz (p < 0.05); children with level A SES outperformed those with level C SES in HG (p < 0.05), but those with level B SES outperformed their level A SES peers in SR (p < 0.05). Within the school context, no equipment for physical education was negatively associated to HG (p < 0.05).
Conclusions: In the primary school years, individual-level characteristics were more important than the school context in explaining variation in physical fitness.
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... Regarding object control skills, boys consistently outperform girls between 6 and 10 years of age. Additionally, Santos et al. (2018) investigated the importance of individual-level and school-level characteristics in explaining variation in PF among Portuguese children (5-10 years old). The results indicated that older children were more physically fit. ...
... Weaver et al. (2021) also reported that the structured schedule provided by schools could help increase cardiorespiratory fitness. Conversely, Santos et al. (2018) showed that no school characteristic accounted for differences in explosive strength and agility among Portuguese children. ...
... For example, a Brazilian study showed increases in children's performance from 5 to 7 years with a plateau in competence beginning at 8 years that persisted until 10 years before children achieve more advanced locomotor and object control skills (Valentini et al., 2016). Similar age-related PF patterns were documented in Peruvian (Santos et al., 2018) and Chinese children, with older individuals showing higher levels of static and explosive muscle strength, agility, and cardiorespiratory fitness compared with their younger peers. The novel finding was that this increase was greater in PF than in object control FMS, which may reflect a nonsynchronicity in their developmental timing and tempo during childhood (Dos Santos et al., 2019;. ...
Objective
The aim was to (1) estimate the relationship between physical fitness (PF) and object control fundamental movement skills (FMS), (2) identify child characteristics that relate with PF and FMS, and (3) examine associations between the school environment, PF, and FMS.
Methods
The sample included 1014 Portuguese children aged 6–10 years from the REACT project. PF was assessed via running speed, shuttle run, standing long jump, handgrip, and the PACER test. Object control FMS were assessed with stationary dribble, kick, catch, overhand throw, and underhand roll. Test performances were transformed into z ‐scores, and their sum was expressed as overall PF and FMS. Child‐level variables included body mass index (BMI) z ‐scores, accelerometer‐measured sedentary time and moderate‐to‐vigorous physical activity, and socioeconomic status (SES). School size, physical education classes, practice areas, and equipment were also assessed.
Results
Approximately, 90% of the variance in object control PF and FMS was at the child level, and 10% at the school level. The correlation between PF and object control FMS was .62, which declined to .43 with the inclusion of covariates. Older, more active, and higher SES children had higher object control PF and FMS, and boys outperformed girls. BMI was negatively associated with PF but not with object control FMS. Sedentary time and number of physical education classes were not significant predictors. Most school predictors did not jointly associate with PF and object control FMS.
Conclusion
PF and object control FMS z ‐scores were moderately related. Not all child characteristics were associated with both PF and object control FMS, and their effect sizes were different. School characteristics only explained 10% of the total variation in PF and object control FMS.
... Sports participation has also been shown to have a stronger relationship with physical fitness compared to non-organized leisure time PA [33]. This may at least partially be attributed to the energetic challenges of club sports participation, as habitual PA bursts may not be of sufficient volume and intensity to modify physical fitness [34,35]. Higher fitness may further contribute to a greater enjoyment of PA and increase the likelihood for a sustainable active lifestyle. ...
... The present study examined differences in various components of physical fitness and body weight by club sports participation in children and adolescents. Consistent with previous studies, absolute performance on fitness tests increased with increasing age [34,39], which can be attributed to increased body size, changes in body composition and neuromuscular maturation [40]. The differences between club sports and non-club sports participants, however, further indicated beneficial associations of club sports participation with physical fitness, particularly regarding endurance, strength, power and agility. ...
Changes in social and built environments most likely contribute to a decline in physical activity (PA) and physical fitness in children and adolescents. Organized sports may be an important component in ensuring adequate fitness, which is an important aspect in general health and well-being. The present study examines differences by club sports participation in cardiorespiratory endurance, muscular strength, power, speed, agility, flexibility and balance in 3293 (55.1% male) Austrian children and adolescents between 6 and 14 years of age. Anthropometric measurements (height and weight) were taken and participants completed the German motor test during regular class time. Even though there was no significant difference in body weight between club sports participants and non-club sports participants, club sports participation was associated with higher physical fitness, particularly regarding endurance, strength, power, and agility. Differences by club sports participation, however, declined during the elementary school years (6-10 years of age), while they became more pronounced during middle school years (10-14 years of age). Club sports participation, therefore, may be a viable option in the promotion of physical fitness, particularly during adolescence. At younger ages, other sources of PA, such as physical education and free play, however, should be considered to ensure sufficient fitness levels that contribute to a healthy and active lifestyle.
... Endurance strength muscle and VO 2 Max should be in the Good category for the futsal player and become the dominant physical fitness component that must be possessed [6]. Therefore, the physical fitness training program must be arranged, organized, and implemented properly and systematically to improve the dominant physical fitness of futsal and increase the required biomotor abilities [22]. Physical fitness highly supports players in a competition to avoid significant fatigue and injuries that could interfere with their performance [9]. ...
... These organizations provided special education services as each element affects these individuals' physical fitness. Maximizing the performance of motor development levels, which have a significant correlation with the physical fitness level, depends on increasing physical activity opportunities (Santos et al. 2018, Nişli et al. 2019. The development of an educational approach that includes the developmental differences of different disability groups brings along the necessity of implementing a training program according to the disability type and characteristics. ...
Introduction: This article reports the physical abilities and physical wellness of three groups of children with different neurodevelopmental disabilities: Autism, Down Syndrome and Intellectual Disability. Methods: The causal-comparative research method was implemented in this study. The participants comprised 32 students with moderate intellectual disabilities, 18 with autism spectrum disorder, and 22 with down syndrome. The body mass index (BMI), flexibility, standing long jump, sitting height, stroke length, and medicine ball throwing levels were measured for physical fitness, and the groups were compared afterward. The Kruskal Wallis-H Test and Mann-Whitney U Test were applied to determine the differences between the groups' physical fitness averages for the statistical analysis. Results: Statistically significant differences were obtained in BMI, standing long jump, stroke length, and medicine ball throwing variables (p < 0.05). However, no statistically significant difference was discovered for the flexibility and sitting height variables (p > 0.05). The BMI, sitting height, and stroke length levels for the group with autism spectrum disorder were higher than the other groups, as the flexibility levels of the group with down syndrome were higher than the other groups. Students with intellectual disabilities were demonstrated to have better values than other groups regarding standing long jump and medicine ball throwing performances. Conclusions: Objective information about the physical fitness of individuals with children with different neurodevelopmental disabilities was obtained. In addition, the data obtained with these children will contribute to future plans for movement training as well as the content and frequency of the interventions, and will guide the development of new strategies to develop physical abilities and physical wellness.
... Sports participation has also been shown to have a stronger relationship with CRF than non-organized leisure-time PA (Jaakkola et al., 2009). This may at least partially be associated with the energetic demands of sports club participation as habitual PA bursts may not be of sufficient volume and intensity to modify CRF (Campos et al., 2017;Santos et al., 2018). Accordingly, sports club participation has been related to greater total PA and a higher probability of meeting PA recommendations (Kokko et al., 2018;Lee et al., 2018). ...
Purpose: This study examined the development of cardiorespiratory fitness (CRF) in children in the transition from kindergarten to basic school according to participation in organized sports and estimated the associations of CRF and body composition indices during the transition from childhood to preadolescence.
Methods: Children participated in the three-staged study (kindergarten, 6.6 years, n = 212; 1st grade, 7.6 years, n = 136; and 5th grade, 11.5 years, n = 142) for 5 years and were categorized into three groups according to their participation in organized sports in the study period (whole period, episodically, and never). Cardiorespiratory fitness was assessed by performing a 20-m shuttle run test, while body composition was measured by skinfold thicknesses, and physical activity was registered with an accelerometer. International gender- and age-specific CRF reference normativities were also used to characterize the participants.
Results: Children who participated consistently in organized sports had significantly higher CRF levels and lower body fatness (31.3 ± 13.5 laps in 20 m shuttle run; 21.1% ± 6.3% body fat) in 11.5 years than in children who had never participated in sports clubs (20.7 ± 12.0 laps in 20-m shuttle run; 26.1% ± 6.8% body fat). Body composition and CRF did not associate in consistently trained children. The proportion of 5th grade children demonstrating age-appropriate healthy CRF was almost threefold higher in the group of consistent sports training among both boys and girls than among non-members of sports clubs.
Conclusion: Consistent attendance in organized sports in childhood and early preadolescence ensures higher CRF and healthier body composition than in children who had no experience of organized sports.
Objetivos:
identificar las características antropométricas y de composición corporal relacionadas con la fuerza prensil manual, y describir las principales características de los protocolos usados para la evaluación de la fuerza prensil manual.
Metodología:
Se desarrolló una revisión sistemática explo ratoria o Scoping Review; la búsqueda fue llevada a cabo en Medline, Web of Science, Science Direct, Scielo y Sportdiscus de EBSCO. Se incluyeron investigaciones originales si incluían fuerza prensil manual y características antropométricas y composición corporal.
Resultados:
Se seleccionaron 59 reportes, publicados entre los años 2005 y 2020. De los 59 reportes seleccionados, la clasificación nu tricional fue la característica más estudiada (n = 25; 42,3%), seguida del índice masa corporal (n = 23; 38,9%). En el 47,5% (28 reportes) no fue clara la cantidad de ensayos realizados en cada individuo para estimar los valores de la fuerza prensil manual. La marca de dinamómetro de la empresa Takei Scientific Instrument Co. Ltd., con un 49,2 % fue la más usada. El indicador de mayor uso fue la fuerza prensil manual absoluta (86,4 %, 51 reportes).
Conclusiones:
Existe una amplia variabilidad en los protocolos utilizados para la evaluación de la fuerza prensil manual con variaciones en la posición del cuerpo, el brazo, la selección de la mano, el número de repeticiones y el intervalo entre las medidas. Se encontró un patrón de valores proporcionales entre la fuerza prensil manual absoluta con el índice de masa corporal, Σ pliegues cutáneos, no obstante, cuando esta se ajusta por masa (fuerza prensil manual relativa) la relación es inversa.
There is only limited evidence to suggest that training during childhood produces greater adaptations than at other ages. The aim of this study was to examine the effects of plyometric training (12 weeks, twice/week, 20 min/day) on physical fitness (PF) and gross motor coordination (GMC) in schoolboys aged 7-9 years. A total of 116 boys were assigned to two groups: plyometric training group (PT,n = 73) and control group (CG,n = 43). The CG maintained their normal daily activities. The PT consisted of twice-weekly exercises on nonconsecutive days for twelve weeks under monitored and controlled conditions. PF (handgrip strength, standing long jump (SLJ), curl-ups, sit and reach, square-test, running speed, and 1 mile run test), GMC, Korper-koordinations-test fur Kinder (KTK), and body mass index (BMI) were assessed. The main results through a 2 × 2 (time × groups) repeated measures analysis variance demonstrated a significant time effect that improves PF and GMC according to the direction of the measure. A group effect was observed only in the abdominal strength test (CG = 12.06% and PT = 17.04%) and moving sideways (CG = 11.1% and PT = 12.4%) showing that independent of the group there was an improvement. A significant interaction effect (time × groups) was observed in the flexibility test (CG = -2.7% and PT = 3.5%) and STJ (CG = 3.1% and PT = 18.5%), as well as jumping sideways (CG = 16.3% and PT = 17.4%) and overall GMC score (CG = 9.8% and PT = 15.9%), showing that gains in these variables were greater in the PT group. The results suggest that 12 weeks of PT improve components of gross motor coordination and health-related physical fitness in children.
Introduction/background:
This study aimed to evaluate the effect of handgrip strength on the associations of body mass index and metabolic syndrome with an indicator of nonalcoholic fatty liver disease in adolescents.
Methodology:
In data of 1690 adolescents aged 10-18 yr from the Korea National Health and Nutrition Examination Survey 2014-2016, alanine amino-transferase levels, age, sex, bodyweight-, sex-, and age-standardized handgrip strength, age- and sex-specific body mass index Z-scores, and metabolic syndrome severity scores were assessed. Nonalcoholic fatty liver disease was defined based on alanine amino-transferase levels (boys ≥52U/L, girls ≥44U/L) in adolescents who were overweight. Moderation analysis via the PROCESS procedure was performed.
Results:
The prevalence of nonalcoholic fatty liver disease was 1.5% among all adolescents and 6.7% among those who were overweight. In all adolescents and adolescents who were overweight, age- and sex-specific body mass index Z-scores and metabolic syndrome scores had positive associations with nonalcoholic fatty liver disease after adjusting for bodyweight-, sex-, and age-standardized handgrip strength. Bodyweight-, sex-, and age-standardized handgrip strength had an inverse association with nonalcoholic fatty liver disease after adjusting for metabolic syndrome scores, and this association became nonsignificant after adjusting for age- and sex-specific body mass index Z-scores. There were positive associations between age- and sex-specific body mass index Z-scores and alanine amino-transferase levels when bodyweight-, sex-, and age-standardized handgrip strength values were ≤-0.13 in overweight adolescents and ≤0.74 in all adolescents, whereas these associations were nonsignificant or negative above those cut-off values. These cut-off values of bodyweight-, sex-, and age-standardized handgrip strength for the relationship between metabolic syndrome scores and alanine amino-transferase levels were -0.15 in overweight adolescents and 0.55 in all adolescents.
Conclusions:
A higher bodyweight-, sex-, and age-standardized handgrip strength may attenuate the risk of obesity and metabolic syndrome for an indicator of nonalcoholic fatty liver disease in adolescents.
Background: There is a renewed interest in longitudinal studies which link children’s growth, motor and cognition development. This is important for both educational outcomes and identification of children who are at risk.
Aim: To identify cross-sectional sex-differences.
Subjects and methods: In total, 1166 Portuguese children, aged 4–11 years, were recruited into the Growth, Motor Development and Cognition Study (GMDC-Vouzela study). Measures included: anthropometry, gestational development, motor coordination, cognitive performance, laterality, physical fitness, metabolic syndrome risk, lifestyle characteristics and environmental exposures. Analysis of covariance was used to compare outcomes between boys and girls, adjusting for chronological age.
Results: Most variables did not show significant differences between the sexes (p > 0.05). However, girls had more body fat mass than boys (p < 0.05) and boys were significantly heavier at birth (p < 0.05); furthermore, boys outperformed girls in a hopping high coordination test (p < 0.001) and were more physically fit (p < 0.05).
Conclusions: Baseline results from the GMDC-Vouzela study indicate the dynamic relationships between children's biological and environmental characteristics. They also highlight lifestyle traits that will most likely effect subsequent growth, motor and cognitive development.
Background:
This study examined associations between students' physical fitness and physical activity (PA), as well as what specific physical fitness components were more significant correlates to being physically active in different settings for boys and girls.
Methods:
A total of 265 fifth-grade students with an average age of 11 voluntarily participated in this study. The students' physical fitness was assessed using four FitnessGram tests, including Progressive Aerobic Cardiovascular Endurance Run (PACER), curl-up, push-up, and trunk lift tests. The students' daily PA was assessed in various settings using a daily PA log for 7 days. Data was analyzed with descriptive statistics, univariate analyses, and multiple R-squared liner regression methods.
Results:
Performance on the four physical fitness tests was significantly associated with the PA minutes spent in physical education (PE) class and recess for the total sample and for girls, but not for boys. Performance on the four fitness tests was significantly linked to participation in sports/dances outside school and the total weekly PA minutes for the total sample, boys, and girls. Further, boys and girls who were the most physically fit spent significantly more time engaging in sports/dances and had greater total weekly PA than boys and girls who were not physically fit. In addition, the physically fit girls were more physically active in recess than girls who were not physically fit.
Conclusions:
Overall, students' performance on the four physical fitness tests was significantly associated with them being physically active during PE and in recess and engaging in sports/dances, as well as with their total weekly PA minutes, but not with their participation in non-organized physical play outside school.
Trial registration:
ClinicalTrials.gov ID: NCT03015337 , registered date: 1/09/2017, as "retrospectively registered".
Objectives: This study aimed to review the scientific evidence on associations between motor competence (MC) and components of health related physical fitness (HRPF), in children and adolescents.
Design: Systematic review. Methods: Systematic search of Academic Search Premier, ERIC, PubMed, PsycInfo, Scopus, SportDiscus, and
Web of Science databases was undertaken between October 2012 and December 2013. Studies examining associations between MC and HRPF components (body weight status, cardiorespiratory fitness,
musculoskeletal fitness and flexibility) in healthy children and adolescents, published between 1990 and 2013, were included. Risk of bias within studies was assessed using CONSORT and STROBE guidelines. The origin, design, sample, measure of MC, measure of the HRPF, main results and statistics of the studies were analyzed and a narrative synthesis was conducted. Results: Forty-four studies matched all criteria; 16 were classified as low risk of bias and 28 as medium risk. There is strong scientific evidence supporting an inverse association between MC and body weight status (27 out of 33 studies) and a positive association between MC and cardiorespiratory fitness (12 out of 12 studies) and musculoskeletal fitness (7 out of 11 studies). The relationship between MC and flexibility was uncertain.
Conclusions: Considering the noted associations between various assessments of MC and with multiple aspects of HRPF, the development of MC in childhood may both directly and indirectly augment HRPF and may serve to enhance the development of long-term health outcomes in children and adolescents.
Background: Lower level of motor competences may result in unsuccessful engaging of children in physical activities as early as pre-school age and also prepubescent ages. This may subsequently lead to a spiral of forming negative attitudes towards an active lifestyle and may be accompanied by a negative trend in weight status and physical fitness outcomes. Objective: The aim of the study was to identify and analyze differences in physical fitness and somatic parameters of primary school-aged children according to level of their gross motor coordination. Methods: A sample of 436 children aged 7 to 10 years, of which were 222 girls and 214 boys, performed physical fitness tests - Eurofit test battery. The level of motor coordination was assessed using the test battery Körperkoordination-Test-für-Kinder (KTK). The anthropometric data (body mass, body height, sum of five skinfolds) were measured. The one-way ANOVA was used to assess differences in physical fitness test items and anthropometry parameters between children with normal motor quotient (MQ ≥ 86) and decreased levels of gross motor coordination (MQ ≤ 85). Results: Research findings indicate a strongly negative trend in physical development of children with motor deficits (MQ ≤ 85). The results of ANOVA revealed significantly less favourable level of most of the assessed physical fitness parameters in children with decreased level of motor coordination. Conclusions: The findings suggest that physical fitness outcomes of primary school-aged children are associated with a lower level of motor coordination. Motor coordination probably plays an important role in preventing, or moderating the so-called negative trajectory leading to childhood overweight or obesity.
Background:
Because fitness level is a potent biomarker of health from an early age, the improvements of physical fitness performance through the promotion of physical activity could be important for the health of preschool children, particularly in obesity prevention.
Objective:
The purpose of this study is to determine the physical fitness in children aged 3-6 years, discriminating performance by sex, age and body mass index (BMI).
Method:
A total of 3868 children from 3 to 6 years agreed voluntarily to participate. Demographic characteristics revealed that 1961 children were male (age: 55.71 ± 11.11 months old, BMI = 16.03 ± 1.93 kg/m2 ), and 1907 were female (age 56.16 ± 0.97 months old, BMI = 15.85 ± 1.89 kg/m2 ), and they were selected from 51 schools in southern Spain.
Results:
Significant differences were found between sexes: boys showed a greater performance on cardio respiratory endurance, reaction time, strength and running speed. We found significant differences by sex in the different age groups (3, 4, 5 and 6 years old).
Conclusions:
Sex differences in physical fitness are evident at an early age; in addition, the relationship between physical fitness and BMI is inconsistent in preschool children. The improvements of physical fitness performance and its association with physical activity could be important for the health of children, particularly in obesity prevention.
The second edition of Growth, Maturation, and Physical Activity has been expanded with almost 300 new pages of material, making it the most comprehensive text on the biological growth, maturation, physical performance, and physical activity of children and adolescents. The new edition retains all the best features of the original text, including the helpful outlines at the beginning of each chapter that allow students to review major concepts. This edition features updates on basic content, expanded and modified chapters, and the latest research findings to meet the needs of upper undergraduate and graduate students as well as researchers and professionals working with children and young adults. The second edition also includes these new features:
- 10 lab activities that encourage students to investigate subject matter outside of class and save teachers time
- A complete reference list at the end of each chapter
- Chapter-ending summaries to make the review process easy for students
- New chapters that contain updates on thermoregulation, methods for the assessment of physical activity, undernutrition, obesity, children with clinical conditions, and trends in growth and performance
- Discussions that span current problems in public health, such as the quantification of physical activity and energy expenditure, persistent undernutrition in developing countries, and the obesity epidemic in developed countries
The authors are three of the world's foremost authorities on children's growth and development. In 29 chapters, they address introductory concepts and prenatal growth, postnatal growth, functional development, biological maturation, influencing factors in growth, maturation and development, and specific applications to public health and sport. In addition, secular trends in growth, maturation, and performance over the past 150 years are considered. You'll be able to recognize risk factors that may affect young athletes; you'll also be able to make informed decisions about appropriate physical activities, program delivery, and performance expectations.
Growth, Maturation, and Physical Activity, Second Edition, covers many additional topics, including new techniques for the assessment of body composition, the latest advances in the study of skeletal muscle, the human genome, the hormonal regulation of growth and maturation, clarification of dietary reference intakes, and the study of risk factors for several adult diseases. This is the only text to focus on the biological growth and maturation process of children and adolescents as it relates to physical activity and performance. With over 300 new pages of material, this text expertly builds on the successful first edition.
Objectives:
Although FitnessGram fitness data on aerobic capacity and body mass index (BMI) have been collected in public schools in Georgia since the 2011-2012 school year, the data have not been analyzed. The primary objective of our study was to use these data to assess changes in fitness among school-aged children in Georgia between 2011 and 2014. A secondary objective was to determine if student fitness differed by school size and socioeconomic characteristics.
Methods:
FitnessGram classifies fitness into the Healthy Fitness Zone (HFZ) or not within the HFZ for aerobic capacity and BMI. We used data for 3 successive school years (ie, 2011-2012 to 2013-2014) obtained from FitnessGram testing of students in >1600 schools. We calculated the percentage of students who achieved the HFZ for aerobic capacity and BMI. We used growth curve models to estimate the annual changes in these proportions, and we determined the effect of school size and socioeconomic status on these changes.
Results:
Both elementary school boys (β = 1.31%, standard error [SE] = 0.23%, P < .001) and girls (β = 1.53%, SE = 0.26%, P < .001) had significant annual increases in achievement of HFZ for aerobic capacity. Elementary school boys (β = 3.11%, SE = 0.32%, P < .001) and girls (β = 3.09%, SE = 0.32%, P < .001) also had significant increases in their BMI HFZ achievement proportions, although these increases occurred primarily between 2011-2012 and 2012-2013. Body mass index HFZ achievement proportions were mixed for middle school students, and we did not observe increases for high school students. Larger school size and higher school socioeconomic status were associated with better aerobic capacity and BMI fitness profiles.
Conclusions:
Surveillance results such as these may help inform the process of designing state and local school-based fitness promotion and public health programs and tracking the results of those programs.
Background:
Level of physical fitness is related to the functional status of most of the bodily functions and so it appears to be very important to identify perinatal factors influencing physical fitness.
Aim:
The purpose of this study was to determine the influence of birth weight on the level of physical fitness in children 6-7years of age.
Subjects and method:
Physical fitness was assessed using EUROFIT tests in 28,623 children, aged 6-7years, from rural areas in Poland. Children below the 10th percentile for birth weight for gestational age were defined as small for gestational age (SGA). The influence of birth weight on parameters of fitness was assessed by means of covariance analysis.
Results:
With the controls of age, sex and body size, children of low birth weight have shown significantly lower levels of body flexibility and running speed. The leg strength of children with SGA turned out to be significantly lower only in 7-year-old boys.
Conclusion:
This study has revealed the significant influence of birth weight on physical fitness. The results suggest the importance of early intervention and its possible benefits for developing and maintaining the proper level of physical fitness further in life.
The objectives of this study were to describe fitness levels, examine associations between physical activity (PA), screen time (ST), and fitness, and examine sex moderating effects in a sample of children. Participants were 649 children (7.8±0.6years; 52.4% female) from Edmonton, Canada. Hours/week of PA and ST were parent-reported. PA was also objectively measured with pedometers and expressed in increments of 1000 steps/day. Fitness components (i.e., vertical jump, sit-and-reach, waist circumference, grip strength, predicted maximal oxygen consumption (VO₂ max), push-ups, partial curl-ups, overall fitness) were measured according to the Canadian PA, Fitness and Lifestyle Approach protocols and expressed as z-scores or low/high fitness. Positive associations were observed between PA and overall fitness for both the complete (Subjective: β=0.009, 95%CI: 0.001, 0.017) and partial (≥3 available fitness measures; Subjective: β=0.006, 95%CI: 0.000, 0.011; Objective: β=0.025, 95%CI: 0.007, 0.042) fitness scores. Subjective (β=0.011, 95%CI: 0.000, 0.022) and objective (β=0.043, 95% CI: 0.008, 0.078) PA were positively associated with vertical jump. Children with higher objective PA were more likely to be in the high push-ups group (OR=1.156, 95%CI: 1.054, 1.267). PA was positively associated with predicted VO₂ max (Subjective: β=0.040, 95%CI: 0.018, 0.063; Objective: β=0.084, 95%CI: 0.012, 0.157) and grip strength (Subjective: β=0.025, 95%CI: 0.011, 0.040) in boys only. ST was negatively associated with grip strength (β=-0.016, 95%CI: -0.028, -0.004) in boys. PA was associated with several components of fitness, especially in boys. However, few associations were observed between ST and fitness. Promoting regular PA in young children may address declining fitness levels.