From one year to the next: Video gaming life-style predicts subsequent psychosocial risk in adolescent boys and girls.

AIM: The ubiquitous societal presence of screens and gaming software is ever growing in popularity. However, can this recreational life-style pose risks for children's psychosocial adjustment? We thus examine associations between gaming life-style and later psychosocial development. METHODS: The study sample originates from the 2120 boys and girls from the Quebec Longitudinal Study of Child Development birth cohort. At age 12, 625 boys and 702 girls from the original sample self-reported the number of hours engaged in video gaming per week and 1 year later, they self-reported psychosocial outcomes. RESULTS: Among boys, higher weekly video gaming frequency at age 12 forecasted increases in subsequent reactive aggression, emotional distress and ADHD symptoms at age 13. For girls, higher weekly video gaming frequency at age 12 predicted increases in subsequent reactive aggression and ADHD symptoms at age 13. No association between video game use and emotional distress was found for girls. CONCLUSION: In both boys and girls, a more intense video gaming life-style predicted subsequent risks for reactive aggression and ADHD symptoms, compared with their same sex counterparts reporting less intensity. For boys only, video gaming was associated with subsequent reactive emotional distress, likely due to the gender differences in violent content. Our data were collected at a time when there were less versatile screen-based technologies; therefore, our findings can be interpreted as very conservative compared to current estimates. Paediatric professionals and allied disciplines must take preventive measures to ensure that parents are aware of the risks associated with excessive use by their sons and daughters.

Participation in organized sport and disruptive behavior in childhood: A prospective, population-based study.

Child disruptive behavior refers to ongoing patterns of disorganized, uncooperative, and defiant behavior. Sport involvement promotes positive child development. However, few longitudinal studies have tested the association between organized sport participation and the behavioral components of disruptive behavior. First, we aim to examine the link between inattentive, hyperactive, aggressive, and oppositional behavior at age 4 years and trajectories of organized sport participation from ages 6 to 10 years. Then, we compare children, according to trajectory membership, on outcome differences on these same behaviors at age 12 years. Data are from the Quebec Longitudinal Study of Child Development (N = 1492). Child behavior was assessed by questionnaires completed by mothers at age 4 years and teachers at age 12 years. Preschool child inattention as perceived by mothers, significantly reduced the odds of middle childhood organized sport participation by 7% (95% CI = 1.00-1.15). Low or inconsistent participation in organized sport was subsequently associated with increased inattention (d = 0.28) by the end of sixth grade. These findings are above and beyond individual and family characteristics and baseline behavior. No other associations were statistically significant. Inattentive children who participated less in organized sport showed a greater likelihood toward increases in attention deficit by the end of sixth grade. To improve engagement from these children, coaches and trainers should use strategies that support positive experiences such as developing a one-to-one alliance with the child, favoring social cooperation through team spirit, and focusing on the performance experience rather than the outcome of winning or losing.

Consistent participation in organized physical activity predicts emotional adjustment in children.

BACKGROUND: The objectives of this study were to derive trajectories of childhood participation in organized physical activity (PA) and to examine how these trajectories are associated with pre-existing and subsequent emotional adjustment. METHODS: Trajectories of mother-reported participation in organized PA were derived from age 6 to 10 for 1492 children from the Québec Longitudinal Study of Child Development birth cohort. Parents and teachers reported on internalizing behavior (emotional distress, anxiety, shyness, social withdrawal) at ages 4 and 12, respectively. RESULTS: Longitudinal latent class analysis identified two typical trajectories of participation in organized PA. The Consistent Participation trajectory (61%) included children with elevated probability of participation at all ages. The Low-Inconsistent Participation trajectory (39%) included children who did not participate or participated only once or twice, generally in late childhood. Pre-existing internalizing behavior at age 4 did not predict trajectory membership. However, children in the Low-Inconsistent Participation trajectory showed higher subsequent emotional distress (B = 0.87, 95% confidence interval [CI] = 0.46-1.28), anxiety (B = 0.61, 95% CI = 0.18-1.04), shyness (B = 0.92, 95% CI = 0.39-1.44), and social withdrawal (B = 0.86, 95% CI = 0.37-1.34) at age 12 than those in the Consistent Participation trajectory. CONCLUSIONS: Our findings suggest that early and sustained involvement in organized PA is beneficial for children's emotional development.

Childhood exercise as medicine: Extracurricular sport diminishes subsequent ADHD symptoms.

Extracurricular sport has been a valued educational investment to promote both physical and mental health in children and adolescents. Few longitudinal studies have tested whether extracurricular sport is associated with inattentive/hyperactive symptoms. Using a prospective-longitudinal birth cohort of 758 girls and 733 boys, we examined the prospective relationship between consistent middle childhood participation in extracurricular sport and subsequent ADHD symptoms. We hypothesized that engaging in extracurricular sport will promote reductions in symptoms. As a predictor, mothers reported on whether the child participated in sport or organized physical activities with a coach/instructor at ages 6, 7, 8, and 10 years. Developmental trajectories of the sport predictor, from ages 6 to 10 years, were generated using longitudinal latent class analysis. At age 12 years, sixth grade teachers reported on child ADHD symptom outcomes observed in the school setting over the last 6 months. ADHD symptoms were linearly regressed on trajectories of participation in organized sport in boys and girls, while controlling for pre-existing child and family characteristics. For girls, consistent participation in organized sport significantly predicted lower subsequent ADHD symptoms, compared with girls with low-inconsistent participation (unstandardized B = 0.07, p ≤ .05, 95% CI, 0.01-0.14). Early sustained middle childhood involvement in organized sport seems beneficial for the subsequent behavioral development of girls but no associations were found for boys. Middle childhood participation in structured venues that demand physical skill and effort with a coach or instructor may thus represent a valuable policy strategy to promote this aspect of behavioral development for girls.

Prospective associations between television in the preschool bedroom and later bio-psycho-social risks.

BACKGROUND: North American child media guidelines suggest screen-free zones without offering clear evidence and alternative harm-reduction strategies. Our hypothesis is that having a bedroom television during the preschool years will be prospectively associated with mental and physical health risks in adolescence. METHODS: Participants are from a prospective-longitudinal birth cohort of 907 girls and 952 boys from the Quebec Longitudinal Study of Child Development. Child outcomes at ages 12 and 13, measured by multiple sources, were linearly regressed on having a bedroom television at age 4. RESULTS: Bedroom television at age 4 predicted a higher body mass index at age 12 (standardized B = 0.10, p < 0.001), more unhealthy eating habits at age 13 (B = 0.10, p < 0.001), higher levels of emotional distress (B = 0.12, p < 0.001), depressive symptoms (B = 0.08, p < 0.001), victimization (B = 0.07, p < 0.001), physical aggression (B = 0.09, p < 0.001), and lowers levels of sociability (B = -0.09, p < 0.001) at age 12, above and beyond pre-existing individual and family factors. CONCLUSION: The bedroom as a screen-based preschool zone does not bode well for long-term cardio-metabolic wellness, mental health, and social relationships.

Prospective associations between participation in leisure-time physical activity at age 6 and academic performance at age 12.

For many children, leisure time represents a privileged moment to engage in physical activity. This study aims to examine prospective associations between kindergarten participation in leisure-time physical activity and academic performance by the end of sixth grade. Gender-specific associations are also explored. Participants are from the Quebec Longitudinal Study of Child Development, a 1997-1998 birth cohort from the province of Quebec, Canada (n = 2837). When children were age 6 (2004), mothers reported on their child's participation in three types of leisure-time physical activity (sports, other structured physical activities, and unstructured physical activities). At age 12 (2010), children's academic indicators were reported by teachers and by children themselves. Academic outcomes were then linearly regressed on leisure-time physical activity participation, while controlling for individual and family confounders. Unstructured physical activities were the most popular among both girls and boys. Sports were the second most popular activity among boys, whereas other structured physical activities were the second most popular among girls. Higher overall participation in leisure-time physical activity at age 6 was associated with better teacher-reported grades in language and math (ß = 0.075 and ß = 0.102, respectively) and self-reported grades in language (ß = 0.103), as well as with higher classroom engagement (ß = 0.077,) at age 12. Regression coefficients are standardized. All the associations were significant (p ≤ .05). Promoting leisure-time physical activity may be an effective way to encourage children to be active and to help them improve their academic performance, both leading to long-term wider benefits.

Prospective associations between toddler televiewing and subsequent lifestyle habits in adolescence.

BACKGROUND: Watching television is a common pastime for very young children. High exposure may negatively influence physical and mental health outcomes. Not much is known about how early exposure relates to lifestyle choices in adolescence. OBJECTIVE: To estimate how toddler televiewing is subsequently associated with lifestyle indicators at adolescence. METHODS: Participants are 986 girls and 999 boys from the Quebec Longitudinal Study of Child Development birth cohort (Canada). Child self-reports lifestyle habits at age 13 that were linearly regressed on parent-reported televiewing at age 2 while adjusting for potential confounders. RESULTS: Every 1 h 13 m increase in daily televiewing was prospectively associated with a 8.2% increased risk of unhealthy eating habits (unstandardized b = 0.05; 95% CI, 0.02 to 0.07), 10.1% decrease in eating breakfast on weekdays (unstandardized b = -0.06; 95% CI, -0.09 to -0.04), 13.3% increase in BMI (unstandardized b = 0.38; 95% CI, 0.26 to 0.50), 4.7% decrease in student engagement (unstandardized b = -0.07; 95% CI, -0.14 to -0.004), and 5.8% increase in concurrent screen time (unstandardized b = 0.06; 95% CI, 0.02 to 0.11). Post hoc simulations of noncompliance with AAP recommendations support their implementation. CONCLUSIONS: Excessive toddlerhood televiewing was prospectively associated with less optimal health and self-invested behavioral dispositions. Lifestyle habits not only affect metabolic risk but may also influence personal success outcomes. These independent relationships, observed more than a decade later, suggest a need for better parental awareness of the way children invest their limited waking hours could affect their long-term life course trajectories.

Children's Early Disruptive Behavior Predicts Later Coercive Behavior and Binge Drinking by Mothers.

PURPOSE: We examined the prospective influence of early child problematic behavior on later coercive interactions and binge drinking by mothers. DESIGN AND METHODS: Canadian participants are from the Quebec Longitudinal Study of Child Development, born between spring 1997 and 1998, which allowed a longitudinal birth cohort design. At the 41months, 628 parents reported on children's oppositional, aggressive, turbulent, and inattentive/hyperactive behavior. Mothers then reported on their own coercive and binge drinking behavior at the 60month follow-up. RESULTS: We estimated a series of ordinary least-squares regressions to examine the relationship between early child behavior problems and later parental coercion and binge drinking, above and beyond many key pre-existing/concurrent confounding factors including prior parenting stress and binge alcohol use. Oppositional, aggressive, and turbulent child behaviors at 41months predicted harsh, negative parenting at 60months. Early inattentive/hyperactive child behavior also forecasted later binge alcohol use by mothers within the same time frame. CONCLUSION: Negative preschool behavior predicted harsh, negative maternal behavior kindergarten entry. Early inattentive/hyperactive behavior also forecasted later binge alcohol use by mothers. Coercive parenting and alcohol use are clinically signs of adult distress. Such parents might use alcohol excessively because of its perceived stress-dampening effects and mental evasion from their life difficulties and frustration experiences. PRACTICE IMPLICATIONS: Problematic preschool behavior can lead to less effective child-rearing and unhealthy parental behavior. Such at-risk mothers would benefit from professional caring practices. Practitioners can inspire change, especially using interaction interventions which encourage positive parent-child relations that, in turn, diminish parental distress.

Prospective Associations Between Early Long-Term Household Tobacco Smoke Exposure and Subsequent Indicators of Metabolic Risk at Age 10.

INTRODUCTION: Although there are established risks associated with gestational tobacco smoke exposure, few studies have addressed the metabolic hazards of domestic exposure in early childhood. This study prospectively examines the long-term relationship between early childhood exposure to household smoke and two adiposity-related measures at age 10. METHODS: Participants from the Quebec Longitudinal Study of Child Development birth cohort were categorized into one of three groups of early childhood household exposure to tobacco smoke over four time points (from ages 1 to 7 years): never-exposed; transient exposure; and continuous exposure. Follow-up measures of body mass index and waist circumference were independently assessed at age 10. RESULTS: Compared to being never exposed, transient and continuous household smoke exposure predicted increases of 0.93 cm (95% confidence interval [CI] between 0.05 and 1.82 cm; P = .03) and 1.56 cm (95% CI between 0.07 and 3.05 cm; P = .04) in children's waist circumference, respectively. Children exposed to transient and continuous household smoke, compared to unexposed children, also showed 0.48 and 0.81 point increases in their body mass index, respectively, both Ps = .005. Once adjusted, for confounding variables, only transient household smoke remained associated with 43% greater odds of belonging to the overweight/obese category (95% CI between 1.12 and 1.81 cm; P < .01). CONCLUSIONS: We found significant long-term prospective associations between home-based secondhand smoke exposure and unhealthy body fat distribution. Waist circumference in youth has become an important risk factor for obesity-related diseases in adulthood. Our findings emphasize the importance public health initiatives and parental sensitization aimed at domestic exposure reductions during the critical early childhood years.

Private screen access in early adolescence predicts subsequent academic and social impairment at the end of high school for boys and girls. / Accès aux écrans dans les espaces privés au début de l'adolescence et difficultés scolaires et sociales à la fin des études secondaires chez les garçons et les filles.

INTRODUCTION: Youth media guidelines in Canada and the United States recommend that bedrooms should remain screen-free zones. This study aims to verify whether bedroom screens at age 12 years prospectively predict academic and social impairment by age 17 years. METHODS: Participants were from the Quebec Longitudinal Study of Child Development birth cohort (661 girls and 686 boys). Linear regression analyses estimated associations between having a bedroom screen (television or computer) at age 12 years and selfreported overall grades, dropout risk, prosocial behaviour and likelihood of having experienced a dating relationship in the past 12 months at age 17 years, while adjusting for potential individual and family confounding factors. RESULTS: For both girls and boys, bedroom screens at age 12 years predicted lower overall grades (B = -2.41, p ≤ 0.001 for boys; -1.61, p ≤ 0.05 for girls), higher dropout risk (B = 0.16, p ≤ 0.001 for boys; 0.17, p ≤ 0.001 for girls) and lower likelihood of having experienced a dating relationship (B = -0.13, p ≤ 0.001 for boys; -0.18, p ≤ 0.001 for girls) at age 17. Bedroom screens also predicted lower levels of prosocial behaviour (B = -0.52, p ≤ 0.001) at age 17 years for boys. CONCLUSION: The bedroom as an early adolescent screen-based zone does not predict long-term positive health and well-being. Pediatric recommendations to parents and youth should be more resolute about bedrooms being screen-free zones and about unlimited access in private exposures in childhood.

Family Meal Environment Differentially Conditions the Prospective Association between Early Childhood Screen Time and Key Social Relationships in Adolescent Girls.

Background: Despite screen time recommendations, children are increasingly spending time on electronic devices, rendering it an important risk factor for subsequent social and developmental outcomes. Sharing meals could offer a way to promote psychosocial development. This study examines the interaction between family meal environment and early childhood screen time on key adolescent social relationships. Methods: Participants are 1455 millennial children (49% boys) from the Quebec Longitudinal Study of Child Development birth cohort. Parents reported on child screen use at ages 2 and 6 years and family meal environment quality at age 6 years. Parents and children reported on parent-child relationships and peer victimization experiences, respectively, at age 13 years. Sex-stratified multiple regression estimated the direct association between screen time trends, family meal environment quality, and their interaction on later social relationship outcomes. Results: For girls, when preschool screen time increased, sharing family meals in high-quality environments was associated with more positive and less conflictual relationships with their mothers, whereas meals shared in low- and moderate-quality environments were associated with fewer instances of victimization by their peers. Non-linear associations were not significant for boys. Conclusion: Capitalizing on family meal environment represents a simple/cost-efficient activity that can compensate for some long-term risks associated with increased screen use, above and beyond pre-existing and concurrent individual and family characteristics. Public health initiatives may benefit from considering family meals as a complementary intervention strategy to screen use guidelines.

Middle Childhood Sport Participation Predicts Timely Long-Term Chances of Academic Success in Boys and Girls by Late Adolescence.

INTRODUCTION: School age children experience successive academic demands which increase over time. Extracurricular sport develops skills which involve physical movement, social rules, formal practice, and rational competition. This may facilitate success. PURPOSE: Using a prospective-longitudinal birth cohort of 746 girls/721 boys, we examined prospective associations between middle childhood sport participation with subsequent indicators of academic success in adolescence. We hypothesized that persistent participation would promote long-term achievement indicators. METHODS: Mothers reported on whether the child participated in sporting activities with a coach/instructor from ages 6 to 10 years. Developmental trajectories of participation were generated using longitudinal latent class analysis and then used to predict outcomes. From ages 12 to 17 years, youth self-reported on academic indicators of success over the last 6 months. These were linearly regressed on trajectories of participation in sport, while controlling for pre-existing and concurrent child/family confounds. RESULTS: Children's sport participation from kindergarten to fourth grade predicted long-term chances of academic success in boys and girls, above and beyond individual/family confounders. Consistent participation predicted increments indicators of future success and reductions in academic failure and dropout risk through to the senior year of secondary school, ranging from 9.1% to 21.3% for girls and 11.7% to 22.9% for boys. CONCLUSIONS: We provide compelling and timely evidence of long-term associations between children's sport participation and subsequent indicators of academic success in typically developing boys and girls by late adolescence. Persistent sport involvement in sport increased educational prospects by late adolescence, potentially improving opportunities for success in emerging adulthood.

Maternal Depressive Symptoms in the First Year after Childbirth Predict Long-Term Developmental Risks in Sons and Daughters.

Under-diagnosed and thus under-treated, maternal depression remains the most common complication of childbearing. Varying symptoms suggest persistence up to more than a decade following childbirth. This implies distinct vulnerabilities for the physical and emotional care of children. Using a prospective-longitudinal sex-stratified birth cohort of 2120 infants, we examined the relationship between early maternal depression symptoms and subsequent child psycho-social and relational characteristics. Mothers self-reported the severity and frequency of depressive symptoms 5 months after childbirth. Parents, teachers, and target participants reported on child mental health and relationships with adults, from kindergarten to tenth grade. A series of least-squares regressions were estimated, while controlling for pre-existing/concurrent child and family confounds. Both sons and daughters of mothers with more depressive symptoms were at risk of experiencing greater psycho-social impairment, classroom rule defiance, difficult relationships with teachers, less enjoyable mealtimes (age 6 years) and sleep, and coercive or inconsistent parenting practices in childhood and adolescence. For boys, these prospective associations were mostly consistent through ages 12 and 15 years. Girls also experienced more problematic interactions through to age 15 years. This study provides observations of distinct long-term vulnerabilities for sons and daughters in association with early maternal distress at important transitional periods of development in early, middle, and later childhood.

Early childhood television viewing and kindergarten entry readiness.

BACKGROUND: Using a large population-based sample, this study aims to verify whether televiewing at 29 mo, a common early childhood pastime, is prospectively associated with school readiness at 65 mo. METHODS: Participants are a prospective longitudinal cohort of 991 girls and 1,006 boys from the Quebec Longitudinal Study of Child Development with parent-reported data on weekly hours of televiewing at 29 mo of age. We conducted a series of ordinary least-squares regressions in which children's scores on direct child assessments of vocabulary, mathematical knowledge, and motor skills, as well as kindergarten teacher reports of socioemotional functioning, were linearly regressed on early televiewing. RESULTS: Every SD increase (1.2 h) in daily televiewing at 29 mo predicted decreases in receptive vocabulary, number knowledge scores, classroom engagement, and gross motor locomotion scores, as well as increases in the frequency of victimization by classmates. CONCLUSION: Increases in total time watching television at 29 mo were associated with subsequent decreases in vocabulary and math skills, classroom engagement (which is largely determined by attention skills), victimization by classmates, and physical prowess at kindergarten. These prospective associations, independent of key potential confounders, suggest the need for better parental awareness and compliance with existing viewing recommendations put forth by the American Academy of Pediatrics (AAP).

Prospective Associations Between Preschool Exposure to Violent Televiewing and Psychosocial and Academic Risks in Early Adolescent Boys and Girls.

OBJECTIVE: Risks of early exposure to media violence remain unclear. This study examines typical early childhood violent media exposure and subsequent psychosocial and academic risks. METHODS: Our longitudinal birth cohort comprised 978 girls and 998 boys. Child-reported and teacher-reported measures of adjustment at age 12 years were linearly regressed on parent-reported televised violence exposure at ages 3.5 and 4.5 years while adjusting for individual/family confounders. RESULTS: For girls, preschool violent televiewing was associated with increases in emotional distress (b = 0.31; 95% confidence interval [CI], 0.13-0.49) and decreases in classroom engagement (b = -0.97; 95% CI, -1.55 to -0.40), academic achievement (b = -2.60; 95% CI, -3.48 to -1.72), and academic motivation (b = -0.58; 95% CI, -1.09 to -0.07) at age 12 years. For boys, preschool violent televiewing was associated with increases in emotionally distressed (b = 0.33; 95% CI, 0.13-0.53), inattentive (b = 0.25; 95% CI, 0.06-0.45), conduct disordered (b = 0.11; 95% CI, 0.00-0.21), and socially withdrawn behavior (b = 0.23; 95% CI, 0.05-0.40), as well as decreases in classroom engagement (b = -0.84; 95% CI, -1.57 to -0.12), academic achievement (b = -1.19; 95% CI, -2.15 to -0.23), and academic motivation (b = -0.58; 95% CI, -1.13 to -0.03) at age 12 years. CONCLUSION: Compared with no preschool exposure, violent televiewing is associated with distinct and enduring psychosocial risks by early adolescence. Acknowledging such risks remains a pertinent health literacy target for pediatric professionals, parents, and communities.

Prospective Associations between Maternal Depressive Symptoms during Early Infancy and Growth Deficiency from Childhood to Adolescence.

Maternal health represents an important predictor of child development; yet it often goes unnoticed during pediatric visits. Previous work suggests that mental state affects parenting. The relationship between infant exposure to maternal depressive symptoms suggests conflicting findings on physical growth. Body mass index (BMI) has not been rigorously examined across development. Using a prospective-longitudinal birth cohort of 2120 infants (50.7% boys), we estimated the prospective relationship between symptoms of maternal depressive symptoms at 5 months postpartum and later BMI in typically developing children. We hypothesized that maternal depressive symptom severity would predict later BMI through to adolescence. Mothers self-reported depressive symptoms at 5 months. Child BMI was measured by a trained research assistant at ages 6, 8, 10, 13, and 15 years. We estimated a series of sex-stratified regressions in which BMI was linearly regressed on maternal symptoms, while controlling for potential pre-existing/concurrent individual and family confounding factors. Boys born to mothers with more severe depressive symptoms at age 5 months had a significantly lower BMI than other boys at subsequent ages. There were no such associations observed for girls. Maternal depressive symptoms were prospectively associated with later BMI for sons and not daughters, predicting risk of faltering in growth through to adolescence. Health practitioners should routinely assess maternal psychological functioning during pediatric visits to optimize parent and child flourishment.

Early childhood television viewing predicts explosive leg strength and waist circumference by middle childhood.

BACKGROUND: The relationship between early childhood television viewing and physical fitness in school age children has not been extensively studied using objective outcome measures. METHODS: Using a sample of 1314 children from the Québec Longitudinal Study of Child Development, we examine the association between parental reports of weekly hours of television viewing, assessed at 29 and 53 months of age, and direct measures of second grade muscular fitness using performances on the standing long jump test (SLJ) and fourth grade waist circumference. RESULTS: Controlling for many potentially confounding child and family variables, each hour per week of television watched at 29 months corresponded to a .361 cm decrease in SLJ, 95% CI between -.576 and -.145. A one hour increase in average weekly television exposure from 29 to 53 months was associated with a further .285 cm reduction in SLJ test performance, 95% CI between -.436 and -.134 cm and corresponded to a .047 cm increase in waistline circumference, 95% CI between .001 and .094 cm. INTERPRETATION: Watching television excessively in early childhood, may eventually compromise muscular fitness and waist circumference in children as they approach pubertal age.

Associations Between Kindergarten Participation in Organized Physical Activity and Subsequent Healthy Body Weight and Leg Strength by the End of Second Grade.

BACKGROUND: Childhood sport helps children develop growth and maturation, while simultaneously offering self-regulation, motor, and social skills training. This study aims to estimate the influence of sport participation at age 6 years on indicators of health at age 8 years, using a prospective longitudinal birth cohort design. METHODS: Participants were 1492 children aged 6-8 years from the Quebec Longitudinal Study of Child Development. Lower muscular power was measured with the standing long jump test. Girth used the children's waist circumference in centimeters. Body mass index was computed from child height and weight. We regressed these directly measured health indicators at age 8 years on parent-reported physical activity at age 6 years using linear Ordinary Least Squares regression. RESULTS: Boys who participated in more physical activity at age 6 years had better lower muscular power (b = 2.368; 95% CI, 0.341 to 4.395) and higher body mass index (b = 0.340; 95% CI, 0.055 to 0.626). No significant results were found for girls. CONCLUSIONS: Our findings suggest that physical activity in kindergarten has a positive impact on muscular power by the end of the second grade in boys. This supports the pertinence of implementing physical activity to a routine early in life to help children improve their general health.

Physical Activity as Both Predictor and Outcome of Emotional Distress Trajectories in Middle Childhood.

OBJECTIVE: This prospective longitudinal study assesses the reciprocal relationship between physical activity, including sport participation, and depressive and anxiety symptoms, conceptualized as emotional distress, over time. METHOD: Boys and girls are from the Quebec Longitudinal Study of Child Development birth cohort (N = 1428). Trajectories of emotional distress symptoms from ages 6 to 10 years, assessed by teachers, were generated using latent class analysis. Multinomial logistic regression analyses examined sport participation at age 5 years, measured by parents, as a predictor of emotional distress trajectory outcomes. Analyses of covariance compared physical activity, measured by children at age 12 years, across different trajectories of emotional distress. RESULTS: We identified 3 emotional distress trajectories: "low" (77%), "increasing" (12%), and "declining" (11%). Boys who never participated in sport at age 5 years were more likely to be in the "increasing" (adjusted odds ratio [OR] = 1.63, 95% confidence interval [CI] = 1.01-2.63) or "declining" (adjusted OR = 2.19, 95% CI = 1.28-3.75) emotional distress trajectories compared with boys who participated in any sporting activity. Furthermore, boys in the "low" emotional distress trajectory demonstrated better physical activity outcomes at age 12 years (F(2, 1438) = 6.04, p < 0.05). These results, exclusively for boys, are above and beyond pre-existing individual and family factors. CONCLUSION: This study supports the relevance of enhancing current public health strategies to understand and promote physical activity and emotional adjustment in early childhood to achieve better a more active lifestyle and overall health across development. We underscore male needs for physical activity for health promotion.