The effect of peer influence on the amount of physical activity performed in 8- to 12-year-old boys

Cardiorespiratory fitness and socioeconomic influences in Chilean schoolchildren: a cross-sectional study

OBJECTIVE

To compare the cardiovascular risk and physical fitness, according to type of school in a national sample of Chilean school students.

METHODS

A total of 7,218 students participated, who completed all the national tests of the National System for Measuring the Quality of Education, which included physical fitness and anthropometric tests. The results were compared according to the type of educational establishment and anthropometric indicators were considered. Physical fitness was measured by lower extremity strength, abdominal strength, upper extremity strength, trunk flexibility, exertional heart rate, and cardiorespiratory fitness. Body mass index, heart rate, and waist-to-height ratio were analyzed as predictors of cardiovascular risk.

RESULTS

There were differences according to the type of establishment in the predictors of cardiovascular risk (p < 0.05). Differences were also found in the physical fitness tests evaluated (p < 0.01). Students in private schools (PSC) and subsidized schools (SC) had lower levels of cardiovascular risk and higher levels of physical fitness than public schools (PS) and schools with delegated administration (DA).

CONCLUSIONS

In conclusion, students in educational establishments with a higher socioeconomic level have lower levels of cardiovascular risk and better physical fitness than students in public establishments. The authors suggest considering specific school interventions to mitigate cardiovascular risk and improve physical fitness among this vulnerable population. To this end, future studies should analyze the characteristics of physical activity and nutritional habits in schools to determine the factors that affect the results.

Physical activity habits and their relationship with sociodemographic factors in Chilean adolescents

Physical activity plays an important role in the well-being and development of adolescents. Physical activity habits expressed in terms of frequency and duration are consistently associated with sociodemographic factors such as age, gender, and socioeconomic status. However, there is less evidence of the relationship between the type and context of physical activity in adolescents. The aim of this article is to analyze physical activity habits and their relationship with sociodemographic factors in Chilean adolescents. The cross-sectional study consisted of 7,263 adolescents aged between 10 and 20 years old, students from both public and private schools in all regions of Chile. Physical activity habits were examined by means of a self-report questionnaire. The age groups were classified according to the three stages of adolescence (early: 10 to 13, middle: 14 to 16, and late: 17 to 20 years old). Socioeconomic level was established based on the school vulnerability index (SVI) of the school attended by each adolescent. In the study it was obvious to the level of physical activity for the adolescents was below the international recommendations. A statistically significant association can also be found between the sociodemographic factors studied and the physical activity habits reported by the young people. The multivariate regression analysis established that the risk of not achieving the physical activity recommendations was 2.8 times higher in females than in males, 2.4 times higher in the older age groups (14-16 and 17-20 years old) compared to the 10-13-year age range and 1.1 times in the medium and high vulnerability groups than in the low socioeconomic vulnerability group. These findings highlight the importance of considering all these factors holistically whenever designing programs or public policies that promote the development of healthy physical activity habits in adolescents.

Use of Focus Groups to Inform a New Community-Based Youth Diabetes Prevention Program

There have been few youth-led diabetes prevention programs. Our objective was to conduct focus groups to explore peer influences on adolescent lifestyle behaviors and strategies for implementing a youth peer education model for diabetes prevention. We conducted six focus groups with 52 youth (ages 13-22; 62% male, 38% female; 64% Hispanic, 36% non-Hispanic Black) from East Harlem, NYC. We used a Thematic Analysis approach to identify major themes, compared findings, and resolved differences through discussion and consensus. Three dominant themes arose: (1) Adolescents generally encounter more unhealthy peer influences on diet and more healthy peer influences on physical activity; (2) Adolescents endorse youth-led diabetes prevention strategies and describe ideal qualities for peer leaders and methods to support and evaluate leaders; (3) Adolescents prefer text messaging to monitor behaviors, track goals, and receive personalized guidance. Using study findings, our Community Action Board developed a peer-led diabetes prevention program for prediabetic adolescents.

Correlations between Physical Activity Participation and the Environment in Children and Adolescents: A Systematic Review and Meta-Analysis Using Ecological Frameworks

Physical activity (PA) and sports are efficient ways to promote the young generation’s physical and mental health and development. This study expected to demonstrate the complexity of correlates associated with children’s and adolescents’ non-organized PA participation. Following the Preferred Reporting Items for Systematic Review and Meta-analysis Protocols (PRISMA), a systematic review and meta-analysis were applied. Seven electronic databases were systematically searched to identify eligible articles based on a series of inclusion and exclusion criteria. The internal validity of the systematic reviews thus identified was evaluated using a validated quality instrument. Calculations were produced in SPSS 27.0 and Comprehensive Meta-Analysis 3.3. Thirty-nine eligible studies (N = 324,953) with moderate to high quality were included. No potential publication bias was detected using statistical analyses. The meta-analysis revealed that the overall ecological factors correlated positively with children and adolescents’ PA; the meta-analytic average of the correlations was (′r = 0.32, p < 0.001). Results from subgroup analysis indicated that theory-based influence factors achieved moderate effect with boys (′r = 0.37, p < 0.001) and girls (′r = 0.32, p < 0.001) in PA participation. Interestingly, higher correlations were found between ecological factors and twins’ PA participation (′r = 0.61, p = 0.001). Further, individual (′r = 0.32, p < 0.001), macro-, and chronosystems factors (′r = 0.50, p < 0.001) appeared slightly more influential than microsystems factors (′r = 0.28, p < 0.001) on children and adolescents’ PA participation. Although findings from the included studies covered were to some extent heterogeneous, it is possible to identify consistent correlates of PA in children and adolescents. The results supported that PA is a complex and multi-dimensional behavior, which is determined by numerous biological, psychological, sociocultural, and environmental factors. Future studies that focus on the integration effect of macrosystem and chronosystem environmental factors, and apply longitudinal designs and objective measurements are encouraged to further unfold the complexity of the ecological system and its implications in promoting children and adolescents’ PA participation.

Physical Activity in Adolescents Living in Rural and Urban New Caledonia: The Role of Socioenvironmental Factors and the Association With Weight Status

Physical activity (PA) is an important factor for the prevention of overweight and obesity, particularly during adolescence. This study focuses on the understudied adolescent population of New Caledonia with the aim to (1) determine the daily PA levels and estimate the sedentary time through out-of-school sitting time; (2) highlight the influence of sociodemographic and environmental factors, and (3) assess the associations of PA and sitting time with overweight and obesity. A sample of 508 school-going adolescents living in New Caledonia was surveyed about their PA habits using the International Physical Activity Questionnaire-Short Form, as well as about the context in which they usually engage in PA. The influences of the place of living and ethnic community were also investigated. Results indicated that about 66% of the adolescents performed an average of at least 60 min of PA daily. Both Melanesian adolescent boys and girls were more active than Caucasian adolescents but only when they lived in rural areas (females: 115 vs. 93 min/day, p = 0.018; males: 133 vs. 97 min/day, p = 0.018). Indeed, PA was reduced in an urban environment (females: 88 min/day; males: 95 min/day, p = 0.028; rural vs. urban in Melanesian adolescents). Melanesian adolescents also spent less time in out-of-school sitting than Caucasian adolescents independently of where they lived (females: 164 vs. 295 min/day, p < 0.001; males: 167 vs. 239 min/day, p = 0.001). Feeling safe was positively associated with PA levels (females: OR_adj = 2.85, p < 0.001; males: OR_adj = 4.45, p < 0.001). In the adolescent boys, accessibility to a suitable place was also an important factor (OR_adj = 2.94, p = 0.002). Finally, while PA and sitting time were negatively associated with overweight in male adolescents (OR_adj = 0.28, p = 0.044 and OR_adj = 0.39, p = 0.004), they were not in females. Living in a rural area allowed the Melanesian adolescents to maintain a more active lifestyle with more physical activities and less sitting time. Our results also indicated that safety was an important driver for engagement in PA. The urban environment in New Caledonia appears to be a contributor of a less active lifestyle in adolescents.

The Experimental Effect of Parent Versus Peer Influence on Children's Physical Activity and Sedentary Behavior

PURPOSE

To assess children's physical activity, sedentary behavior, liking, and motivation during 3 separate simulated recess conditions: playing alone, with their parent participating, and with their peer participating.

METHODS

Children participated in the 3 separate conditions. During each condition, the children had access to an outdoor playground and sedentary activity options for 30 minutes. Accelerometry recorded the physical activity. Time allocated to sedentary options was monitored via a stopwatch. A visual analog scale was used to assess liking, and motivation was assessed as the children's willingness to participate in an additional 10 minutes of each condition.

RESULTS

The children sat 88% less and were 33% more physically active with their peer versus playing alone. The children also sat 65% less during the parent condition than alone. Lastly, the children reported ≥34% liking and were ≥2-fold more likely to participate in the additional 10-minute activity bout during the parent and peer conditions than alone. The differences were significant (P ≤ .05) except for the children's decision to participate in the additional 10 minutes in the parent versus the alone condition (P = .058).

CONCLUSIONS

Relative to the alone condition, the presence of a peer or parent reduced sedentary behavior and increased liking and the motivation to participate in that condition. However, only the presence of a peer increased physical activity versus alone.

Relationship between chewing features and body mass index in young adolescents

BACKGROUND

Behavioural aspects of chewing may influence food intake, nutritional status and in turn body weight.

OBJECTIVES

The current study aimed to study chewing features in adolescents as they naturally occur in home-based settings, and to test for a possible association with weight status.

METHODS

Forty-two adolescents (15.3 ± 1.3 years) were recruited (21 with healthy-weight/21 with overweight). Using a smartphone-assisted wearable electromyographic device, the chewing features of each participant were assessed over one evening, including the evening meal, in their natural home setting.

RESULTS

The mean (±SD) for chewing pace was 1.53 ± 0.22 Hz, chewing power 30.1% ± 4.8%, number of chewing episodes 63.1 ± 36.7 and chewing time 11.0 ± 7.7 minutes. The chewing pace of the group with overweight was slower than that of healthy weight (-0.20 Hz; 95% CI, -0.06 to -0.33; P = .005) while their chewing time was shorter (-4.9 minutes; 95% CI, 0.2-9.7; P = .044). A significant negative correlation was observed between BMI z-score and chewing pace (R = -.41; P = .007), and between BMI z-score and chewing time (R = -0.32; P = .039).

CONCLUSION

The current study suggests that adolescents who are overweight eat at a slower pace for a shorter period of time than their counterparts who are a healthy weight. This unexpected finding based on objective data appears to conflict with existing questionnaire findings but provides impetus for further work testing the effectiveness of changing eating behaviour as a weight-management intervention in youth.

VO2, Liking, and Relative Reinforcing Value of Cooperative and Competitive Exergame Play in Young Children

The purpose of the current study was to examine physiologic response, liking, and relative reinforcing value (RRV) of children playing an exergame with a friend under two goal structures: competitive and cooperative. A sample of twenty participants (8.7 ± 1.3 years old) and a self-selected friend completed three conditions: rest, competitive, and cooperative play. During the competitive condition, participants played Nintendo Wii Tennis® against their friend. During cooperative play, participants and their friend played together against a computer avatar. During each condition, oxygen consumption (VO2, ml·kg-1·min-1) and liking (visual analog scale) were recorded. After finishing all conditions, children completed an RRV computer task to assess their motivation to play the competitive versus cooperative goal structures. During this task children performed work (button presses) to participate in additional competitive play, cooperative play, or a combination. The output maximum (Omax), or maximum work for each goal structure, was used as the measure of RRV. It was determined that VO2 was significantly (p ≤ 0.001) greater for cooperative and competitive play than rest. Liking was significantly greater for cooperative play than rest (p ≤ 0.001) and competitive play (p = 0.03). There were no significant differences (p > 0.05) between cooperative and competitive play for VO2 or Omax. In conclusion, while liking was greater for the cooperative condition versus competitive, motivation did not differ between goal structures. Further investigation into methods of making physical activity more reinforcing, in addition to well-liked by children, is necessary to optimize this behavior.

The Influence of Friends and Psychosocial Factors on Physical Activity and Screen Time in Normal and Overweight Adolescents: A Mixed-Methods Analysis

BACKGROUND

Understanding factors that influence physical activity (PA) and sedentary behavior is crucial to develop interventions to improve adolescents' health-related behaviors.

PURPOSE

To compare the influence of friends and psychosocial factors on moderate-to-vigorous physical activity (MVPA) and screen time (ST) between normal weight (NW) and overweight (OW) adolescents.

METHODS

In all, 21 OW and 21 NW adolescents wore accelerometers and completed questionnaires assessing MVPA, ST, and psychosocial variables. The MVPA and ST were assessed in nominated friends. Adolescents participated in focus groups assessing influence on activity behaviors.

RESULTS

There were no differences in MVPA; however, NW adolescents reported less ST than OW adolescents (8.9 vs 13.1 h/wk, P = .04). For OW adolescents, friends' ST ( P = .002) and psychosocial factors ( P = .05) were associated with ST, while only PA self-efficacy was associated with MVPA. For NW adolescents, only friends' MVPA ( P = .04) was associated with self-reported PA. Exploratory analyses revealed differences among weight status and gender. Focus group discussions revealed that friends influenced both OW and NW adolescents' MVPA; however, this appeared to be more apparent for NW males, while psychosocial factors played a role in both OW and NW females. The OW adolescents reported that friends were more of an influence on their ST levels, while NW adolescents indicated that their ST was not affected by their friends' behaviors.

CONCLUSIONS

Interventions to increase MVPA and/or decrease ST may need to be tailored for NW and OW adolescents.

The Effect of the Presence of an Internet-Connected Mobile Tablet Computer on Physical Activity Behavior in Children

BACKGROUND

Mobile Internet-connected electronic devices provide access to activities that have traditionally been associated with sedentary behavior. Because they are portable, these devices can be utilized in any environment. Therefore, providing children with access to these devices in environments that typically promote physical activity may result in a reduction in physical activity behavior.

PURPOSE

To assess children's physical and sedentary (ie, sitting) activity with and without the presence of a mobile Internet-connected tablet computer.

METHODS

A total of 20 children [6.7 (1.9) y old] participated in 2 simulated recess conditions in a gymnasium on separate days. During each condition, children had free-choice access physical activity options and a table of sedentary activities for 40 minutes. During 1 session, the iPad was present, and in the other session, it was not. Physical activity was monitored via an accelerometer, and sedentary time was monitored via a stopwatch.

RESULTS

Children significantly (P ≤ .03) reduced average physical activity intensity and increased their sedentary behavior with the iPad present [4.4 (4.0) metabolic equivalents/min and 20.9 (12.4) min sitting] versus the condition without the iPad present [5.3 (4.0) metabolic equivalents/min and 13.6 (13.2) min sitting].

CONCLUSION

Introducing an mobile Internet-connected tablet computer into a gymnasium reduced children's physical activity intensity by 17% and increased sedentary behavior by 54%.

Implications of Social Groups on Sedentary Behavior of Children with Autism: A Pilot Study

This pilot study compared sedentary behavior (SB) of children with autism (ASD) to typically developing peers (TD), and evaluated the influence of social contexts within free play (FP) and organized activity settings on SB of children with ASD during an inclusive summer camp. Participants with ASD were matched with TD peers by age and gender, and a modified OSRAC-P was utilized to assess SB and social context by setting. SB did not differ by diagnosis (ASD, TD), setting, or social contexts. In FP, children with ASD spent significantly more time in SB within social contexts compared to solitary contexts. ASD-related social deficits may facilitate SB in children with ASD during summer camp FP social contexts, compared to a solitary context.

Comparison of Path Length and Ranges of Movement of the Center of Pressure and Reaction Time and Between Paired-Play and Solo-Play of a Virtual Reality Game

AIMS

To test whether paired-play will induce longer path length and ranges of movement of the center of pressure (COP), which reflects on balance performance and stability, compared to solo-play and to test the difference in the path length and ranges of movement of the COP while playing the virtual reality (VR) game with the dominant hand compared to playing it with the nondominant hand.

METHODS

In this cross-sectional study 20 children (age 6.1 ± 0.7 years old) played an arm movement controlled VR game alone and with a peer while each of them stood on a pressure measuring pad to track the path length and ranges of movement of the COP.

RESULTS

The total COP path was significantly higher during the paired-play (median 295.8 cm) compared to the COP path during the solo-play (median 189.2 cm). No significant differences were found in the reaction time and the mediolateral and anterior-posterior COP ranges between solo-play and paired-play. No significant differences were found between the parameters extracted during paired-play with the dominant or nondominant hand.

DISCUSSION

Our findings imply that the paired-play is advantageous compared to solo-play since it induces a greater movement for the child, during which, higher COP velocities are reached that may contribute to improving the balance control of the child. Apart from the positive social benefits of paired-play, this positive effect on the COP path length is a noteworthy added value in the clinical setting when treating children with balance disorder.

The social context moderates the relationship between neighborhood safety and adolescents' activities

Studies of neighborhood safety and physical activity have typically neglected to consider the youth's peer context as a modifier of these relationships. This study fills this gap in testing the independent and interactive effects of perceived neighborhood safety and time spent with friends and peers on young adolescents' physical activity and sedentary behavior. Participants (N = 80; ages 13-17) completed the Pedestrian/Traffic Safety and Crime Safety subscales of the adolescent version of the Neighborhood Environment Walkability Scale (NEWS). An experience sampling methodology was used to assess sedentary behaviors/screen time and the social context in which physical activity and sedentary time/behavior occurred. Physical activity was assessed via accelerometry. Multilevel models were used to estimate the relationships between predictors (neighborhood safety and social context) and outcomes (physical activity and sedentary time/behavior). Frequency of peer/friend interactions moderated the relationships between neighborhood safety and adolescents' physical activity and sedentary behavior. Specifically, physical activity was more strongly influenced by neighborhood safety among adolescents who reported spending less time with peers and friends than among those who reported frequent peer interactions. Among youths who perceived that their neighborhoods were safer, spending more time with friends and peers was related to greater engagement in sedentary activities, whereas this was not the case among adolescents who perceived that their neighborhoods were less safe. The peer social context moderates the relationship between perceived neighborhood safety and adolescents' physical activity and sedentary behavior. Improving social interactions at the individual level within neighborhoods may decrease concerns of safety.

Feasibility and efficacy of the Great Leaders Active StudentS (GLASS) program on children's physical activity and object control skill competency: A non-randomised trial

OBJECTIVES

This study aimed to assess the feasibility and efficacy of the Great Leaders Active StudentS (GLASS) program, a school-based peer-led physical activity and object control skill intervention.

DESIGN

The study employed a quasi-experimental design.

METHODS

The study was conducted in two elementary schools, one intervention and one comparison, in Newcastle, New South Wales (NSW), Australia from April to June 2015 (N=224 students). Peer leaders (n=20) in the intervention school received training to deliver two 30-min object control skill sessions per week to students in Kindergarten, Grades 1 and 2 (5-8 years, n=83) over one school term (10 weeks). The primary outcome was pedometer assessed physical activity during school hours. Secondary outcomes included students' object control skill competency and peers' leadership self-efficacy and teacher ratings of peers' leadership skills.

RESULTS

Almost all (19/20) GLASS sessions were delivered by peer leaders who reported high acceptability of the program. The treatment-by-time interaction for students' physical activity during school hours was not significant (p=0.313). The intervention effect on students' overall object control skills was statistically significant (mean difference 5.8 (95% CI 4.1, 7.4; p<0.001)). Teacher-rated peer leadership significantly improved (0.70; 95% CI 0.38-1.01); p<.001)).

CONCLUSIONS

The GLASS program was found to be both feasible and acceptable. The intervention also resulted in improvements in students' overall object control skills as well as teacher-rated peers' leadership behaviours. Future fully powered trials using peer leaders to deliver fundamental movement skill (FMS) programs are warranted.

Social influences on eating and physical activity behaviours of urban, minority youths

OBJECTIVE

Social relationships can impact youths' eating and physical activity behaviours; however, the best strategies for intervening in the social environment are unknown. The objectives of the present study were to provide in-depth information on the social roles that youths' parents and friends play related to eating and physical activity behaviours and to explore the impact of other social relationships on youths' eating and physical activity behaviours.

DESIGN

Convergent parallel mixed-methods design.

SETTING

Low-income, African American, food desert neighbourhoods in Baltimore City, MD, USA.

SUBJECTS

Data were collected from 297 youths (53 % female, 91 % African American, mean age 12·3 (sd 1·5) years) using structured questionnaires and combined with in-depth interviews from thirty-eight youths (42 % female, 97 % African American, mean age 11·4 (sd 1·5) years) and ten parents (80 % female, 50 % single heads of house, 100 % African American).

RESULTS

Combined interpretation of the results found that parents and caregivers have multiple, dynamic roles influencing youths' eating and physical activity behaviours, such as creating health-promoting rules, managing the home food environment and serving as a role model for physical activity. Other social relationships have specific, but limited roles. For example, friends served as partners for physical activity, aunts provided exposure to novel food experiences, and teachers and doctors provided information related to eating and physical activity.

CONCLUSIONS

Obesity prevention programmes should consider minority youths' perceptions of social roles when designing interventions. Specifically, future research is needed to test the effectiveness of intervention strategies that enhance or expand the supportive roles played by social relationships.

The ACT-i-Pass study protocol: How does free access to recreation opportunities impact children's physical activity levels?

BACKGROUND

Physical activity during childhood is associated with a multitude of physical, behavioural, and psychological health benefits. Identification of effective population level strategies for increasing children's physical activity levels is critical for improving the overall health of Canadians. The overall objective of this study is to assess how a naturally-occurring, community-level intervention which offers Grade 5 children in London, Canada a free access pass to physical activity opportunities (facilities and programs) for an entire school year can lead to increased physical activity among recipients.

METHODS/DESIGN

This study adopts a longitudinal cohort study design to assess the effectiveness of improving children's access to physical activity opportunities for increasing their physical activity levels. To meet our overall objective we have three aims: (1) to assess whether the provision of free access increases children's physical activity levels during and after the intervention compared to a control group; (2) to assess how and why child-specific trajectories of physical activity (between-children differences in level of physical activity measured across time) in the intervention group differ according to children's individual and household characteristics; and (3) to explore additional factors that are unaccounted for in the theoretical model to gain a further understanding of why the free access intervention had varying effects on changing physical activity levels. We will be addressing these aims using a mixed methods approach, including: a series of youth surveys conducted before, during, immediately after, and 4-months after the intervention; parent surveys before, during, and post-intervention; real-time tracking of the access pass use during the intervention; and focus groups at the conclusion of the intervention. Data compiled from the youth surveys will provide a subjective measure of physical activity to be used as our outcome measure to address our primary aims.

DISCUSSION

The results of this study can inform policy- and decision-makers about the sub-groups of the population that benefitted the most (or least) from the intervention to provide more specific information on how to develop and target future interventions to have a greater impact on the physical activity levels and overall health of children.

The effect of a peer on VO2 and game choice in 6-10 year old children

Relative to sedentary video games (e.g., Playstation 2®), playing physically active video games (e.g., Nintendo Wii Sports Boxing®) significantly increases caloric expenditure in children. Studies have demonstrated that the presence of a peer increases physical activity in children. We sought to determine if children would expend more energy and find playing the “exergame” (Wii) more motivating than the sedentary video game (Playstation 2) when with a peer. Seventeen children (age 8.5 ± 0.4 years) rested, played the sedentary video game and “exergame” for 10 min each, in two conditions: one in which the children rested/played the games alone (alone condition) and another in which they played with a peer (peer condition). Oxygen consumption (VO₂), and liking (visual analog scale) was assessed for each 10-min condition. After three 10-min resting/gaming conditions, motivation was assessed using a relative reinforcing value task in which children performed computer mouse presses to gain additional access for either the sedentary video game or “exergame.” VO₂ was greater (p < 0.001) during “exergame” play (mean = 12.17 ± 4.1 ml·kg⁻¹·min⁻¹) vs. rest (mean = 5.14 ± 1.46 ml·kg⁻¹·min⁻¹) and the sedentary video game (mean = 5.83 ± 2.1 ml·kg⁻¹·min⁻¹). During the peer condition, there were no significant differences (p > 0.05) in VO₂ relative to the alone condition. In an exploratory analysis boys exhibited a greater (p = 0.02) increase in VO₂ from rest to “exergame” (Δ 9.0 ± 3.7 ml·kg⁻¹·min⁻¹), relative to girls (Δ 4.9 ± 2.9 ml·kg⁻¹·min⁻¹). Boys showed a significantly greater increase (p = 0.05) in VO₂ from the resting condition to “exergame” in the presence of a peer (Δ 11.1 ± 5.3 ml·kg⁻¹·min⁻¹) vs. the alone condition (Δ 6.8 ± 3.1 ml·kg⁻¹ ·min⁻¹). Liking was significantly (p < 0.001) greater for “exergame” (7.7 ± 1.9 cm) and the sedentary video game (8.3 ± 1.3 cm) relative to rest (4.0 ± 2.8 cm). Motivation for “exergame” significantly decreased (p = 0.03) from alone (340.8 ± 106.8 presses) to the peer condition (147.8 ± 81.6 presses).

Conclusion: VO₂ was greater during “exergame” play relative to the sedentary video game. The presence of a peer did not increase VO₂ during “exergame” play. Surprisingly, the presence of a peer decreased children's motivation to play “exergame” vs. the sedentary video game.

Peers and Obesity during Childhood and Adolescence: A Review of the Empirical Research on Peers, Eating, and Physical Activity

Obesity during childhood and adolescence is a growing problem in the United States, Canada, and around the world that leads to significant physical, psychological, and social impairment. In recent years, empirical research on factors that contribute to the development and maintenance of obesity has begun to consider peer experiences, such as peer rejection, peer victimization, and friendship. Peer experiences have been theoretically and empirically related to the “Big Two” contributors to the obesity epidemic, eating and physical activity, but there has not been a comprehensive review of the extant empirical literature. In this article, we review and synthesize the emerging theoretical and empirical literatures on peer experiences in relation to: (a) eating (food consumption and food selection); and (b) physical activity, during childhood and adolescence. A number of limitations and issues in the theoretical and empirical literatures are also discussed, along with future research directions. In conclusion, we argue that the involvement of children and adolescents’ peer networks in prevention and intervention efforts may be critical for promoting and maintaining positive behavioral health trajectories.

Modelling the vicious circle between obesity and physical activity in children and adolescents using a bivariate probit model with endogenous regressors

The increasing prevalence of obesity in children and adolescents has become one of the most important public health issues around the world. Lack of physical activity is a risk factor for obesity, while being obese could reduce the likelihood of participating in physical activity. Failing to account for the endogeneity between obesity and physical activity would result in biased estimation. This study investigates the relationship between overweight and physical activity by taking endogeneity into consideration. It develops an endogenous bivariate probit model estimated by the maximum likelihood method. The data included 4008 boys and 4197 girls in the 5th-9th grades in Taiwan in 2007-2008. The relationship between overweight and physical activity is significantly negative in the endogenous model, but insignificant in the comparative exogenous model. This endogenous relationship presents a vicious circle in which lower levels of physical activity lead to overweight, while those who are already overweight engage in less physical activity. The results not only reveal the importance of endogenous treatment, but also demonstrate the robust negative relationship between these two factors. An emphasis should be put on overweight and obese children and adolescents in order to break the vicious circle. Promotion of physical activity by appropriate counselling programmes and peer support could be effective in reducing the prevalence of obesity in children and adolescents.

Peer influence and physical activity behavior in young children: an experimental study

BACKGROUND

There is evidence that the presence of a friend increases physical activity behavior in school-aged children (≥ 8 years old) and in young adolescents. Little is known about the developmental trajectory of the effects of peer influences on children's physical activity. Therefore, we sought to test the effect of the presence versus absence of a friend on physical activity in young children (≤ 6 years old).

METHODS

Physical activity was assessed, via accelerometery, in 3- to 6-year-old children, during 2 social conditions: alone and in the presence of a friend. During each condition, children were taken to a gymnasium and had free access to physical and sedentary activities for 30 minutes. In one condition children were tested alone (solo play), whereas in the other they were tested in the presence of a friend who had access to the same activities.

RESULTS

Children exhibited 54% greater (P < .02) average accelerometer counts during the friend condition (mean = 2629, SD = 1080 or 5.7 METs) than during the solo play condition (mean = 1707, SD = 1009 or 4.5 METs).

CONCLUSIONS

The presence of a friend contributes to increased physical activity behavior in young children.

Influence of peers and friends on overweight/obese youths' physical activity

This review offers a theoretical framework to account for the effects of peers on youths' physical activity. Our research indicates the following: 1) that the youth are more physically active in the presence of friends and peers than in the presence of family members or when alone, 2) peers and friends increase overweight/obese youths' motivation to be physically active, 3) peers' weight status does not moderate the effect of peers on youths' physical activity, and 4) experiencing negative peer interaction, such as ostracism, decreases physical activity in youth. We propose that the consideration of the peer social context as a contributor to physical (in)activity and maintenance of overweight status may further our understanding of physical and behavioral health trajectories and improve prevention and intervention efforts.

Influence of peers and friends on children's and adolescents' eating and activity behaviors

Obesity during childhood and adolescence is a growing problem in the United States, Canada, and around the world that leads to significant physical, psychological, and social consequences. Peer experiences have been theoretically and empirically related to the "Big Two" contributors to the obesity epidemic, unhealthy eating and physical inactivity. In this article, we synthesize the empirical literature on the influence of peers and friends on youth's eating and physical activity. Limitations and issues in the theoretical and empirical literatures are also discussed, along with future research directions. In conclusion, we argue that the involvement of children's and adolescents' peer networks in prevention and intervention efforts may be critical for promoting and maintaining positive behavioral health trajectories. However, further theoretical and empirical work is needed to better understand the specific mechanisms underlying the effects of peers on youth's eating and physical activity.

The effect of simulated ostracism on physical activity behavior in children

OBJECTIVES

To assess the effects of simulated ostracism on children's physical activity behavior, time allocated to sedentary behavior, and liking of physical activity.

METHODS

Nineteen children (11 boys, 8 girls; age 11.7 ± 1.3 years) completed 2 experimental sessions. During each session, children played a virtual ball-toss computer game (Cyberball). In one session, children played Cyberball and experienced ostracism; in the other session, they were exposed to the inclusion/control condition. The order of conditions was randomized. After playing Cyberball, children were taken to a gymnasium where they had free-choice access to physical and sedentary activities for 30 minutes. Children could participate in the activities, in any pattern they chose, for the entire period. Physical activity during the free-choice period was assessed via accelerometery and sedentary time via observation. Finally, children reported their liking for the activity session via a visual analog scale.

RESULTS

Children accumulated 22% fewer (P < .01) accelerometer counts and 41% more (P < .04) minutes of sedentary activity in the ostracized condition (8.9(e+4) ± 4.5(e+4) counts, 11.1 ± 9.3 minutes) relative to the included condition (10.8(e+4) ± 4.7(e+4) counts, 7.9 ± 7.9 minutes). Liking (8.8 ± 1.5 cm included, 8.1 ± 1.9 cm ostracized) of the activity sessions was not significantly different (P > .10) between conditions.

CONCLUSIONS

Simulated ostracism elicits decreased subsequent physical activity participation in children. Ostracism may contribute to children's lack of physical activity.