Physical fitness in childhood and adolescence: a powerful marker of health

A 3-year longitudinal analysis of changes in fitness, physical activity, fatness and screen time

AIM

To analyse whether changes in physical activity index (PAI), screen time (ST: television, computer) and body mass index (BMI) made a contribution to longitudinal changes in fitness of children and adolescents. Additionally, we analysed the interaction between baseline fitness level and changes in fitness.

METHODS

This is a 3-year longitudinal study of 345 high school students aged 11-19 years. Students performed curl-ups, push-ups and 20-m shuttle run tests from Fitnessgram. PA and ST were evaluated using a standard questionnaire. Standardized scores of fitness tests were summed. Changes over time were calculated as Delta(1) (2007 minus 2006), Delta(2) (2008 minus 2007) and Delta(3) (2008 minus 2006).

RESULTS

Changes in PAI were positively and independently associated with changes in fitness in Delta(1), Delta(2) and Delta(3). Changes in BMI were negatively associated with changes in fitness in Delta(3). Participants highly fit at baseline were those who showed positive changes in PAI over Delta(3), decreased changes in ST and had the lowest increase in BMI over 3 years compared with those low-fit at baseline.

CONCLUSIONS

Changes in BMI were associated with changes in fitness over 3 years. However, changes in PAI were the best predictor for changes in fitness in each year and over the 3 years of evaluation in youth.

Grip Strength Performances by 5- to 19-Year-Olds

Accurate measures of muscular strength can yield insights about children's growth and development. The purpose of this study was to examine grip strength performances by boys and girls ages 5 to 19 years. A Jamar dynamometer was used to measure grip strength by 736 boys and girls ages 5 to 19 years. Multiple regression equations were applied to analyze the data. Overall, age-sex trends were similar to previous reports as boys and girls increased their performances across age levels. After age 12, boys' mean grip strength increased at a faster rate than girls'. However, participants in the present study performed better in the upper age ranges (13–19 yr.) than did boys and girls tested a generation ago. Potential associations between activity choices and grip strength are discussed.

Physical fitness in children with high motor competence is different from that in children with low motor competence

BACKGROUND

Physical therapists often treat children with low motor competence. Earlier studies have demonstrated poor physical fitness outcomes and a reduced level of physical activity for these children compared with their peers with normal motor skills.

OBJECTIVE

The aim of this study was to examine how physical fitness developed over time in 2 groups of children: those with a low level of competence in motor skills (low motor competence [LMC]), and those with a high level of competence in motor skills (high motor competence [HMC]).

DESIGN AND METHODS

From an initial sample of 67 children, a group of 18 was identified as having HMC or LMC on the Movement Assessment Battery for Children and was selected for the present study. Eight children (3 girls and 5 boys) comprised the LMC group, and 10 children (4 girls and 6 boys) made up the HMC group. A longitudinal design was implemented, and physical fitness in the 2 groups was evaluated by measuring different fitness components over a period of 32 months.

RESULTS

A mixed-effects analysis of variance revealed significant main effects for group and for time but no group x time interaction effect. The LMC group performed less well on all physical fitness measures than the HMC group, and both groups scored significantly higher on the physical fitness test after a period of 32 months. The lack of a significant interaction effect indicated that the relative differences in physical fitness outcomes between the groups were relatively constant over time.

LIMITATIONS

This study was limited by the small sample size and lack of assessment of anthropometric variables and children's perceived self-efficacy.

CONCLUSIONS

Children with LMC are likely to have poor physical fitness compared with children with HMC. The differences in physical fitness outcomes between the groups were relatively constant over time. Given that various physical fitness components are linked to different health outcomes, these consequences are matters of concern for both current health status and later health status in children with LMC.

The influence of fitness on insulin resistance in obese children

An increasingly pervasive environment of reduced activity and easy access to high caloric food is leading to an epidemic of poor cardiovascular fitness, obesity, insulin resistance and type 2 diabetes (T2DM) in children. Studies have shown that insulin resistance (IR) to be an independent predictor for morbidity as well as mortality. These serve as a strong stimulus for public health strategies to improve fitness in children and adolescents. Methods to assess IR, improve IR and understand complications are increasingly important in children.

Adiposity and quality of life: a case study from an urban center in Nigeria

OBJECTIVE

To determine relationship between adiposity indices and quality of life (QOL) of residents of a housing estate in Lagos, Nigeria.

DESIGN

Cross-sectional survey employing multistep random sampling method.

SETTING

Urban residential estate.

PARTICIPANTS

This study involved 900 randomly selected residents of Abesan Housing Estate, Lagos, Nigeria.

MAIN OUTCOME MEASURES

Body mass index (BMI); waist circumference (WC); waist-to-hip ratio (WHR); triceps skin-fold thickness (TSFT); and abdominal skin-fold thickness (ASFT) were measured using International Standard of Anthropometric Assessment methods. QOL was assessed using Short Form-20.

ANALYSIS

Data were analyzed using the Pearson product moment correlation coefficient and multiple regression analysis.

RESULT

The mean age of participants was 37.7 +/- 14.3 years, with a range of 20 to 80 years. The mean values of adiposity indices were 24.1 +/- 4.3 kg/m(2) (BMI), 11.5 +/- 5.3 mm (TSFT), 18.5 +/- 6.2 mm (ASFT), 81.8 +/- 11.2 cm (WC), and 0.89 +/- 0.1 (WHR). Although the overall mean QOL score was 72.02 +/- 11.9, women had significantly (P < .05) lower scores (70.1 +/- 5.2) than men (73.5 +/- 11.3). There was inverse correlation between QOL and each of the age and adiposity indices.

CONCLUSION AND IMPLICATIONS

Quality of life of the urban-dweller Nigerians decreased with increasing body adiposity and age. This finding suggests the need to further educate the Nigerian public on the association between high body fat and poor health.

Sports camp with six months of support from a local sports club as a treatment for childhood obesity

Aims: Although childhood obesity is becoming increasingly prevalent, treatment options are limited and the continued development of effective treatment strategies is necessary. It is equally important to explore involvement of other resources in society, such as sports associations. This study was designed to investigate the possibility of reducing the degree of obesity in obese children by focusing on physical activity as an intervention. Methods: Seventy-six children (40 boys) aged 8—12 years (mean age 10.5 years, mean body mass index (BMI) 28.9, standard deviation (SD) 3.0; mean BMI z-score 3.24, SD 0.49) were invited to participate in a one-week sports camp and six-month support system. After the camp a sports coach from a local sports club supported the child during participation in a chosen sport for six months. Weight, height, body composition (using dual energy x-ray absorptiometry and magnetic resonance imaging), and lifestyle (using a questionnaire) were measured at baseline and after 12 months. Data were pooled from two camps, one with a self-selected control group and one randomized controlled trial. Results: Twelve months after the camp the intervention group had a significant decrease in BMI z-score (baseline BMI z-score 3.22; follow up 3.10, p = 0.023). The control group also reduced their BMI z-score (baseline BMI z-score 3.27; follow up 3.18, p = 0.022). No differences were found in baseline values, follow-up values, or changes in BMI z-score between groups, nor between boys and girls. Conclusions: The focus on physical activity as an intervention had no effect on degree of obesity when compared with a waiting list control group.

Socio-economic factors and active commuting to school in urban Spanish adolescents: the AVENA study

BACKGROUND

This study aimed: (i) to describe the patterns of commuting to school in urban Spanish adolescents; and (ii) to examine the associations between active commuting to school (ACS) and socio-economic factors.

METHODS

From the AVENA Study, 2183 adolescents (1142 females) aged 13-18.5 years were gathered. Mode and time of transportation to school were self-reported by the adolescents. Parental education level (primary, secondary or university degree), parental professional level (managerial, skilled worker or unskilled worker/unemployed) and the type of school (public or private) were self-reported by the parents. The relationships between ACS and socio-economic factors were analysed by binary logistic regression.

RESULTS

Nearly <65% of the adolescents reported ACS and 83% of them spent <15 min travelling to school. In male adolescents, maternal primary education level showed an odds ratio (OR) of 1.55 (95% confidence interval, 1.12-2.15), with respect to mothers with a university degree. In female adolescents, mothers with a primary education level showed an OR of 0.68 (0.50-0.92), with respect to mothers with a university degree. Low maternal professional level showed an OR of 1.70 (1.29-2.24), with respect to high maternal professional levels. Students attending public schools showed an OR of 3.47 (2.46-4.90), with respect to students from private schools.

CONCLUSION

Most of the adolescents actively commuted to school, yet the time spent commuting was low. Socio-economic level seems to be inversely related to the ACS in adolescents. Type of school and maternal educational level were the main predictors of ACS.

Components of the Metabolic Syndrome among a Sample of Overweight and Obese Costa Rican Schoolchildren

Background

The term “pediatric metabolic syndrome” includes a cluster of cardiovascular risk factors such as insulin resistance, dyslipidemia (including increased triglycerides and decreased HDL cholesterol), hypertension, and obesity in children. No studies have been performed on this syndrome in a pediatric population in Costa Rica.

Objective

To establish the prevalence of metabolic syndrome and its components in 8- to 10-year old prepuberal overweight and obese schoolchildren.

Methods

This cross-sectional survey was conducted in 214 overweight and obese boys and girls, aged 8 to 10 years, who were selected from six urban schools from San José, Costa Rica. Anthropometric measurements and determinations of blood glucose, insulin, triglycerides, total cholesterol, HDL cholesterol, and high-sensitivity C-reactive protein (hs-CRP) were performed. The home-ostasis model assessment of insulin resistance (HOMA-IR) index and the Castelli index were calculated to assess insulin resistance and cardiovascular risk, respectively. Social and lifestyle variables were obtained through validated questionnaires.

Results

A total of 110 boys and 104 girls participated in this study; 37.9% of them were overweight and 62.1% were obese. Compared with boys, girls were more sedentary and had higher insulin levels (16.05 ± 10.45 μIU/mL vs. 12.72 ± 7.63 μIU/mL, p = .008), body fat (36.5% vs. 30.9%, p < .001), and HOMA-IR indexes (3.5 ± 2.4 vs. 2.8 ± 1.7, p = .014) but lower HDL cholesterol (0.99 ± 0.23 mmol/L vs. 1.08 ± 0.27 mmol/L, p = .009). Obese children had significantly higher mean serum concentrations of insulin, hs-CRP, and triglycerides and higher insulin resistance (estimated by HOMA-IR) than overweight children, but lower mean serum levels of HDL cholesterol. The prevalence of metabolic syndrome in the study population was 5.6%. Other risk factors for developing cardiovascular disease and type 2 diabetes had high prevalence rates among the children: sedentarism (40.6%), family history of type 2 diabetes (73.3%), high LDL cholesterol levels (≥ 2.84 mmol/L) (57.0%), hyperinsulinemia (> 10.5 μIU/mL) (59.8%), insulin resistance (estimated by HOMA-IR ≥ 2.4) (55.1%), and total cholesterol (> 4.39 mmol/L) (60.7%). Children with metabolic syndrome had significantly higher body mass indexes, glucose levels, and triglyceride levels and lower HDL cholesterol levels than children without metabolic syndrome. Insulin had a very strong positive correlation with HOMA-IR values ( r = 0.982), and hs-CRP had a mild positive correlation with body mass index ( r = 0.296) and body fat ( r = 0.320).

Conclusions

This study reported a prevalence of 5.6% of metabolic syndrome among a sample of Costa Rican overweight and obese prepuberal children. Lifestyle interventions focusing on weight reduction and increasing physical activities should be promoted by education and health authorities in order to avoid the early development and onset of type 2 diabetes and atherosclerosis in childhood.

Criterion-related validity of the one-mile run/walk test in children aged 8-17 years

We assessed the criterion-related validity of Cureton's equation for estimating peak oxygen consumption (VO(2peak)) from the one-mile run/walk test in endurance-trained children aged 8-17 years. Altogether, 66 physically active white children and adolescents (32 girls, 34 boys) completed a graded exercise test to volitional exhaustion and the one-mile run/walk test. Cureton's equation was used to estimate VO(2peak), and was assessed using several error measures. Agreement between measured VO(2peak) and estimated VO(2peak) was analysed by the Bland and Altman method. The correlation coefficient between measured VO(2peak) and one-mile run/walk time was -0.59 (P < 0.001) and that between measured and estimated VO(2peak) was 0.70 (P < 0.001). The mean difference between measured and estimated VO(2peak) was 10 ml . kg(-1) . min(-1) (95% CI = 9.2-11.8; P < 0.001). The standard error of the estimate was 3 ml . kg(-1) . min(-1), and the percentage error was 32%. There was a positive association between the measured and estimated VO(2peak) difference and the measured and estimated VO(2peak) mean, which indicates that the higher the VO(2peak) the higher the error of the estimate. These findings did not change markedly when the analyses were performed by sex, age group or body mass status. These results suggest that Cureton's equation systematically underestimates VO(2peak) in endurance-trained children with high VO(2peak).

Alternative treatments in pediatric bipolar disorder

There has been growing interest in the use of complementary and alternative treatments in pediatric bipolar disorder (BPD). There are limited data, however, regarding the safety and efficacy of these treatments. This article discusses select complementary and alternative treatments that have been considered for use in pediatric BPD and/or depression, including omega-3-fatty acids, inositol, St. John's wort, SAMe, melatonin, lecithin, and acupuncture. Background information, reference to available adult and pediatric data, proposed mechanisms of action, dosing, side effects, and precautions of these treatments are included. Across the board, more research is necessary and warranted regarding the long-term safety and efficacy of available complementary and alternative treatments for the management of pediatric BPD.

High fitness is associated with a healthier programming of body composition at adolescence

The programming effect of birth weight on later body composition has become of increasing interest in recent years. This programming effect is affected by factors such as gender. Physical fitness could be another factor of influence. This study aimed to examine whether handgrip strength (HG) or cardiovascular fitness (CVF) modify the associations between birth weight and body composition in adolescents. A sample of 1,740 (942 females) adolescents aged 13 to 18.5 years, born at more than 35 weeks of gestation, from the AVENA study was studied. Waist circumference was measured, percentage body fat was calculated from skinfold thicknesses and fat free mass was derived by subtracting fat mass from total body weight. HG and CVF were assessed using the HG test and the 20 m shuttle run test, respectively. Birth weight was positively associated with fat free mass in females with high (above the median) CVF (P < 0.001), but not in those with low (below the median) CVF. In contrast, birth weight was positively associated with total and central adiposity in males with low HG (both P = 0.002), but not in those with high HG. These results suggest that the programming effect of birth weight on later body composition is dependent on gender and fitness level. A high birth weight may have a healthy programming effect on body composition in those adolescents with a high fitness level, being associated with increased fat free mass levels in females and not showing the increased adiposity levels observed in unfit males.

Are muscular and cardiovascular fitness partially programmed at birth? Role of body composition

OBJECTIVE

To determine whether birth weight is associated with handgrip strength and cardiovascular fitness in adolescence and, if so, how these associations are influenced by current body composition.

STUDY DESIGN

A total of 1801 adolescents (983 females), age 13 to 18.5 years, from the AVENA (Alimentación y Valoración del Estado Nutricional de los Adolescentes Españoles [Food and Assessment of the Nutritional Status of Spanish Adolescents]) study were evaluated. Handgrip strength and cardiovascular fitness were assessed using the handgrip test and the 20-m shuttle run test, respectively.

RESULTS

Birth weight was positively associated with handgrip strength in females after controlling for current age, gestational age, breast-feeding, and adolescent body mass index (P = .002), body fat percentage (P < .001), or waist circumference (P = .005), but not after controlling for fat-free mass. The associations were similar yet weaker in males. Females with high birth weight (>90th percentile) had greater handgrip strength than those with normal (10th to 90th percentile) or low (<10th percentile) birth weight, after adjusting for body fat percentage (P = .004). All of the differences became nonsignificant after adjusting for adolescent fat-free mass. Birth weight was not associated with cardiovascular fitness.

CONCLUSIONS

High birth weight is associated with greater handgrip strength in adolescents, especially in females, yet these associations seem to be highly explained by fat-free mass.

Insulin sensitivity, VO2max and body composition in severely obese Swedish children and adolescents

AIM

The aim of this study was to identify relationships between insulin sensitivity (SI), cardiorespiratory fitness and body composition in severely obese Swedish children and adolescents.

METHODS

Two hundred and twenty-eight obese children (119 girls, 8-16 years, body mass index (BMI) 23.2-57.0 kg/m(2)) performed a frequently sampled intravenous glucose tolerance test (FSIVGTT), a submaximal bicycle ergometry test and a dual-energy X-ray absorptiometry (DEXA).

RESULTS

Mean SI (SD) was 0.38 (0.32) (x10(-5)/min/pM). SI correlated positively with relative body mass (BM) VO(2)max (r = 0.42) (p < 0.001), relative fat-free mass (FFM) VO(2)max (r = 0.36) (p < 0.001) and negatively with body mass index standard deviation score (BMI SDS) (r =-0.22) (p = 0.001). SI did not correlate with percent body fat (r =-0.01) and absolute VO(2)max (r = 0.01). In multiple regression analyses with SI as dependent variable, VO(2)max and body composition, together with gender, age and Tanner stage, explained 20-26% of the variance.

CONCLUSION

Relative (BM) VO(2)max and relative (FFM) VO(2)max were stronger predictors of SI than percent body fat in severely obese children and adolescents. The study confirms that cardiorespiratory fitness is of importance for the metabolic syndrome in the studied population. Efforts to improve SI should include physical activity targeting cardiorespiratory fitness also in severely obese children and adolescents.

Physical fitness and physical activity at age 13 years as predictors of cardiovascular disease risk factors at ages 15, 25, 33, and 40 years: extended follow-up of the Oslo Youth Study

OBJECTIVE

Few studies have examined the association of childhood physical activity and physical fitness with cardiovascular disease risk factors in adulthood. Furthermore, interpretation of these findings is hampered by methodologic shortcomings. In a population-based cohort study, we explored the influence, if any, of childhood physical activity and physical fitness on later cardiovascular disease risk factors.

METHODS

Data were taken from the Oslo Youth Study, a prospective cohort study that began in 1979, when 1016 students (mean age: 13 years; range: 11-15 years) who were attending 6 schools were invited to participate in a health education intervention. Cardiovascular disease risk factor data were collected at baseline and again in 1981 (mean age: 15 years; range: 13-17 years), 1991 (mean age: 25; range: 23-27 years), 1999 (mean age: 33; range: 31-35 years), and 2006 (mean age: 40; range: 38-42 years).

RESULTS

At baseline, physical fitness was inversely related to BMI, triceps skinfold thickness, and blood pressure (systolic and diastolic; N = 716). These associations were also present in prospective analyses at ages 15 (N = 472), 25 (N = 280; except for systolic blood pressure), and 33 years (N = 410, only BMI measured)-albeit with progressively diminishing magnitude-but were lost at 40 years (N = 294). There were fewer relationships with cardiovascular disease risk factors when physical activity was the exposure of interest. Controlling for educational attainment of both the parent and the study member had little impact on these associations.

CONCLUSIONS

Although childhood physical fitness seems to reveal some inverse associations with obesity and blood pressure in early adulthood, these effects diminished markedly into middle age.

Pilot study for an age- and gender-based nutrient signaling system for weight control

Nutrient signaling has recently shown how nutraceuticals regulate specific functions of the brain and adipose tissue. In this pilot study to find an effective nutrient signaling system to cause weight loss, a double-blind placebo-controlled trial using leucine, olive oil, and fish oil was conducted on volunteers to signal metabolic and appetite effects to regulate body weight, while controls took only fiber. Men and women aged 18-26 and 39-62 years were given different dosages that they took orally twice daily for 14 days while recording body weight, followed by 2 weeks to check rebound. Most young men and women lost weight on low dose leucine and olive oil. Mature men required higher doses. Mature women's weight was affected least, though results are consistent with a hypothesis that sufficient leucine and docosahexaenoic acid would be effective. Determining how age affects signaling pathways by nutrients will be important to reduce risk of chronic disease associated with age and obesity. This pilot study has led to hypotheses of practical strategies.

Active play and screen time in US children aged 4 to 11 years in relation to sociodemographic and weight status characteristics: a nationally representative cross-sectional analysis

BACKGROUND

The high prevalence of childhood obesity underscores the importance of monitoring population trends in children's activity and screen time, and describing associations with child age, gender, race/ethnicity, and weight status. Our objective was to estimate the proportion of young children in the US who have low levels of active play or high levels of screen time, or who have both these behaviors, and to describe associations with age, gender, race/ethnicity, and weight status.

METHODS

We analyzed data collected during the National Health and Nutrition Examination Surveys 2001-2004, a US nationally representative cross-sectional study. We studied 2964 children aged 4.00 to 11.99 years. Our main outcomes were reported weekly times that the child played or exercised hard enough to sweat or breathe hard (active play), daily hours the child watched television/videos, used computers, or played computer games (screen time), and the combination of low active play and high screen time. Low active play was defined as active play 6 times or less per week. High screen time was defined as more than 2 hours per day. We accounted for the complex survey design in analyses and report proportions and 95% confidence intervals. We used Wald Chi-square to test for differences between proportions. To identify factors associated with low active play and high screen time, we used multivariate logistic regression.

RESULTS

Of US children aged 4 to 11 years, 37.3% (95% confidence interval, 34.1% to 40.4%) had low levels of active play, 65.0% (95% CI, 61.4% to 68.5%) had high screen time, and 26.3% (95% CI, 23.8% to 28.9%) had both these behaviors. Characteristics associated with a higher probability of simultaneously having low active play and high screen time were older age, female gender, non-Hispanic black race/ethnicity, and having a BMI-for-age > or =95th percentile of the CDC growth reference.

CONCLUSION

Many young children in the US are reported to have physical activity and screen time behaviors that are inconsistent with recommendations for healthy pediatric development. Children who are overweight, approaching adolescence, girls, and non-Hispanic blacks may benefit most from public health policies and programs aimed at these behaviors.

Maternal depressive symptoms and physical activity in very low-income children

OBJECTIVE

To test the contribution of maternal depression during late infancy to physical activity in children 5 years later.

METHOD

Children (n = 168) from very low-income households in semiurban Mexico were assessed as toddlers (15 months, Time 1) and at pre-school age (4-6 years, Time 2). Child low activity level (<20 minutes of activity daily for <7 d/wk) at Time 2 was the primary outcome measure and maternal depressive symptoms (Center for Epidemiologic Studies-Depression Scale) by self-report at Time 1 was the primary independent variable. Covariates tested included child age, sex, BMI percentile, television viewing and behavior (Behavior Problem Index subscales), current maternal depressive symptoms, age, BMI and physical activity level, and family socioeconomic status; all covariates were assessed at Time 2 except for socioeconomic status.

RESULTS

At 4 to 6 years old, 27.5% of children were categorized with low activity level. Exposure to high maternal depressive symptoms at child age 15 months was associated with an increased risk of having a low activity level at age 4 to 6 years (OR, 2.38; 95% CI, 1.05-5.40); results were unchanged with the inclusion of current maternal depressive symptoms. High child TV viewing was significantly associated with low activity level (OR, 5.44; 95% CI, 2.06-14.3), but did not change the effect of maternal depressive symptoms in early childhood. Tests of mediation revealed that current child internalizing behavior, but not externalizing behavior, significantly attenuated the association between early high maternal depressive symptoms and later childhood activity level.

CONCLUSION

Exposure to maternal depressive symptoms in late infancy is a risk factor for low activity level in later childhood and the association may be mediated by child internalizing factors.

Perceived sports competence mediates the relationship between childhood motor skill proficiency and adolescent physical activity and fitness: a longitudinal assessment

BACKGROUND

The purpose of this paper was to investigate whether perceived sports competence mediates the relationship between childhood motor skill proficiency and subsequent adolescent physical activity and fitness.

METHODS

In 2000, children's motor skill proficiency was assessed as part of a school-based physical activity intervention. In 2006/07, participants were followed up as part of the Physical Activity and Skills Study and completed assessments for perceived sports competence (Physical Self-Perception Profile), physical activity (Adolescent Physical Activity Recall Questionnaire) and cardiorespiratory fitness (Multistage Fitness Test). Structural equation modelling techniques were used to determine whether perceived sports competence mediated between childhood object control skill proficiency (composite score of kick, catch and overhand throw), and subsequent adolescent self-reported time in moderate-to-vigorous physical activity and cardiorespiratory fitness.

RESULTS

Of 928 original intervention participants, 481 were located in 28 schools and 276 (57%) were assessed with at least one follow-up measure. Slightly more than half were female (52.4%) with a mean age of 16.4 years (range 14.2 to 18.3 yrs). Relevant assessments were completed by 250 (90.6%) students for the Physical Activity Model and 227 (82.3%) for the Fitness Model. Both hypothesised mediation models had a good fit to the observed data, with the Physical Activity Model accounting for 18% (R2 = 0.18) of physical activity variance and the Fitness Model accounting for 30% (R2 = 0.30) of fitness variance. Sex did not act as a moderator in either model.

CONCLUSION

Developing a high perceived sports competence through object control skill development in childhood is important for both boys and girls in determining adolescent physical activity participation and fitness. Our findings highlight the need for interventions to target and improve the perceived sports competence of youth.