Perceived social pressure and intention to play through injuries in junior ice hockey: The sporting environment matters.

Playing when injured is a risky yet common business among ice hockey players. Conceptualized within the framework of the theory of planned behaviour, the current cross-sectional study aimed to test a multiple-mediator model linking players' perceived social pressure to their intention to play when injured. We tested whether social pressure is directly and indirectly (via attitudes, subjective norms, perceived behavioural control avoidance, and situational temptation) related to intention to play when injured. We recruited 186 junior players aged 16-20 years (mean age = 17.85; standard deviation = 1.35) from two Norwegian ice hockey leagues (under 18 and under 20 years of age). The data were analysed using a linear regression procedure and a bias-corrected bootstrapping technique to measure indirect effects. The results revealed a positive direct and indirect (via attitudes, subjective norms, and situational temptation) relationship between players' perceived social pressure and their intention to play when injured. In conclusion, players that perceived pressure to play despite being injured, who perceived positive consequences of doing so, who believed that people close or important to them approved of them doing so, and who perceived game-specific temptations, were more likely to report a stronger intent to play the game when injured.

Observational vs coaching feedback on non-dominant whole-body motor skill performance - application to technique training.

We studied the effect of peer- and self-observational feedback versus coaching feedback during technique training on performance in competitive adolescent cross-country skiers. Fifty-four skiers (14.3 ± 0.6 years) were divided into a control group and three intervention groups (dyad practice, video, or coaching feedback), which practiced in the asymmetrical uphill sub-technique G2 on one side (non-dominant side), but not the other (dominant side) for 6 × 30 min over a 5 weeks period, on roller skis outdoors. High-speed performance and skiing economy were assessed on a roller ski treadmill before and after the intervention, and a questionnaire was answered post-intervention. The video feedback (p = .025, d = .65) and coaching feedback (p = .007, d = .89) groups improved high-speed performance during the intervention and an ANCOVA showed a tendency for different change scores between interventions (F3,49  = 2.5, p = .068, η p 2  = .134), with a difference between the coaching feedback and dyad practice (p = .05). No change was seen in skiing economy in any group. Coaching feedback ranked higher on enjoyment compared with dyad practice (p < .001) and led to higher self-perception of improved technique compared with the control group (p = .038). Overall, feedback from a competent coach seems better than observation for improving performance in young athletes, although self-observation through video with attentional cues seems a promising tool for increasing individual feedback when coaching large groups.

Initial psychometric testing of the coach-adapted version of the empowering and disempowering motivational climate questionnaire: A Bayesian approach.

The present study examined the psychometric properties of the coach-adapted version of the Empowering and Disempowering Motivational Climate Questionnaire (EDMCQ) using Bayesian structural equation modelling (BSEM). The sample included 780 (Mage = 36.4; SD = 10.8; males n = 698; females n = 54; 28 participants did not report sex) youth sport coaches representing five European countries (i.e., England, France, Greece, Norway, and Spain). The results did not support a 34-item five-factor, hierarchical, a two-factor BSEM, or a bifactor BSEM model across the participating countries. However, the results supported a reduced 19-item first-order, two-factor BSEM model that largely showed approximate metric invariance, but not approximate scalar invariance across the five countries. The pool of items constituting empowering and disempowering motivational climates should be refined to further enhance the empirical operationalisation of the coach-adapted version of the EDMCQ. Advancing the quality of translation-back-translation procedures across cultures and conducting multi-national pilot testing seems warranted as well. These recommendations may help to identify the distinctive aspects of each underlying sub-dimension of the EDMCQ, where coaches are the respondents, and pave the way for further examination of the proposed hierarchical multidimensional factor structure and the cross-cultural equivalence of the EDMCQ for this population.

A study of coach-team perceptual distance concerning the coach-created motivational climate in youth sport.

The purpose of this study was to examine whether coach-team perceptual distance regarding the coach-created motivational climate related to achievement goal orientations and affective responses. To this end, we used polynomial regression analysis with response surface methodology. The sample consisted of 1359 youth soccer players (57.8% male; Mage  = 11.81 years, SD = 1.18), belonging to 87 different teams (Msize  = 16.47), and 87 coaches (94.6% male, Mage  = 42 years, SD = 5.67). Results showed that team perceptions of a coach-created mastery climate were positively related to team-rated task goal orientation and enjoyment, whereas team perceptions of a coach-created performance climate were positively related to team-rated ego goal orientation and anxiety, and negatively related to team-rated enjoyment. When the coach and the team were in perceptual agreement, the outcomes increased as both coach and team perceptions of the climate increased. In situations of perceptual disagreement, the most negative effects were seen when the coach held a more favorable perception of the motivational climate compared to the team. The findings highlight the importance of perceptual agreement between the coach and his/her team, contributing to the literature focusing on the effects of the coach-created motivational climate.

Promoting additional activity in youth soccer: a half-longitudinal study on the influence of autonomy-supportive coaching and basic psychological need satisfaction.

This study investigated the relationships between perceptions of coach autonomy support, basic psychological need satisfaction and the frequency at which youth soccer players engage in additional soccer activity outside of team sessions. We employed structural equation modelling to test a two-wave (T1 and T2) half-longitudinal study to see if basic psychological need satisfaction mediated the relationship between coach autonomy support and additional soccer activity across a competitive season. The sample consisted of 527 youth soccer players, aged 10-15 years. Results revealed moderate to strong temporal stability for autonomy, competence, relatedness and frequency of additional soccer activity. Furthermore, no support is offered for mediation as T1 coach autonomy support was not related to any of the three basic needs at T2 when accounting for their T1 levels. However, a positive relationship between T1 autonomy and T2 additional soccer activity emerged. This suggests that those who experience high levels of autonomy in the team setting at the start of the season report an increased frequency of additional activity at the end of the season. Results are discussed in light of the Self-Determination Theory and the Trans-Contextual Model.

Objectively recorded physical activity in pregnancy and postpartum in a multi-ethnic cohort: association with access to recreational areas in the neighbourhood.

BACKGROUND: Physical activity may reduce the risk of adverse pregnancy outcomes; however, compared to non-pregnant women, a lower proportion of pregnant women meet the physical activity guidelines. Our objectives were to explore overall changes and ethnic differences in objectively recorded moderate-to-vigorous intensity physical activity (MVPA) during pregnancy and postpartum and to investigate the associations with objective and perceived access to recreational areas. METHODS: We analysed 1,467 person-observations from 709 women in a multi-ethnic population-based cohort, with MVPA data recorded with the SenseWear™ Pro(3) Armband in early pregnancy (mean gestational week (GW) 15), mid-pregnancy (mean GW 28) and postpartum (mean postpartum week 14). MVPA was limited to bouts ≥10 min. Women were nested within 56 neighbourhoods defined by postal code area. We derived neighbourhood-level objective access to recreational areas (good vs limited) by geographic information systems. We collected information about perceived access (high vs low perception) to recreational areas in early pregnancy. We treated ethnicity, objective and perceived access as explanatory variables in separate models based on linear mixed effects regression analyses. RESULTS: Overall, MVPA dropped between early and mid-pregnancy, followed by an increase postpartum. Western women performed more MVPA than women in other ethnic groups across time points, but the differences increased postpartum. Women residing in neighbourhoods with good objective access to recreational areas accumulated on average nine additional MVPA minutes/day (p < 0.01) compared with women in neighbourhoods with limited access. Women with perceptions of high access to recreational areas accumulated on average five additional MVPA minutes/day (p < 0.01) compared with women with perceptions of low access. After mutual adjustments, perceived and objective access to recreational areas remained significantly associated with MVPA. The association between MVPA and access to recreational areas did not differ by time point, ethnic group or socio-economic position. CONCLUSIONS: In all ethnic groups, we observed a decline in MVPA between early and mid-pregnancy. However, at both time points during pregnancy, and especially three months postpartum, Western women were more physically active than ethnic minority women. In all ethnic groups, and at all three time points, both objective and perceived access to recreational areas were positively associated with MVPA levels.

Effects of physical activity on schoolchildren's academic performance: The Active Smarter Kids (ASK) cluster-randomized controlled trial.

OBJECTIVE: To investigate the effect of a seven-month, school-based cluster-randomized controlled trial on academic performance in 10-year-old children. METHODS: In total, 1129 fifth-grade children from 57 elementary schools in Sogn og Fjordane County, Norway, were cluster-randomized by school either to the intervention group or to the control group. The children in the 28 intervention schools participated in a physical activity intervention between November 2014 and June 2015 consisting of three components: 1) 90min/week of physically active educational lessons mainly carried out in the school playground; 2) 5min/day of physical activity breaks during classroom lessons; 3) 10min/day physical activity homework. Academic performance in numeracy, reading and English was measured using standardized Norwegian national tests. Physical activity was measured objectively by accelerometry. RESULTS: We found no effect of the intervention on academic performance in primary analyses (standardized difference 0.01-0.06, p>0.358). Subgroup analyses, however, revealed a favorable intervention effect for those who performed the poorest at baseline (lowest tertile) for numeracy (p=0.005 for the subgroup∗group interaction), compared to controls (standardized difference 0.62, 95% CI 0.19-1.07). CONCLUSIONS: This large, rigorously conducted cluster RCT in 10-year-old children supports the notion that there is still inadequate evidence to conclude that increased physical activity in school enhances academic achievement in all children. Still, combining physical activity and learning seems a viable model to stimulate learning in those academically weakest schoolchildren.

Predicting who fails to meet the physical activity guideline in pregnancy: a prospective study of objectively recorded physical activity in a population-based multi-ethnic cohort.

BACKGROUND: A low physical activity (PA) level in pregnancy is associated with several adverse health outcomes. Early identification of pregnant women at risk of physical inactivity could inform strategies to promote PA, but no studies so far have presented attempts to develop prognostic models for low PA in pregnancy. Based on moderate-to-vigorous intensity PA (MVPA) objectively recorded in mid/late pregnancy, our objectives were to describe MVPA levels and compliance with the PA guideline (≥150 MVPA minutes/week), and to develop a prognostic model for non-compliance with the PA guideline. METHODS: From a multi-ethnic population-based cohort, we analysed data from 555 women with MVPA recorded in gestational week (GW) 28 with the monitor SenseWear™ Pro3 Armband. Predictor variables were collected in early pregnancy (GW 15). We organized the predictors within the domains health, culture, socioeconomic position, pregnancy, lifestyle, psychosocial factors, perceived preventive effect of PA and physical neighbourhood. The development of the prognostic model followed several steps, including univariate and multiple logistic regression analyses. RESULTS: Overall, 25 % complied with the PA guideline, but the proportion was lower in South Asians (14 %) and Middle Easterners (16 %) compared with Westerners (35 %). Among South Asians and Middle Easterners, 35 and 28 %, respectively, did not accumulate any MVPA minutes/week compared with 18 % among Westerners. The predictors retained in the prognostic model for PA guideline non-compliance were ethnic minority background, multiparity, high body fat percentage, and perception of few physically active friends. The prognostic model provided fair discrimination between women who did vs. did not comply with the PA guideline. CONCLUSION: Overall, the proportion who complied with the PA guideline in GW 28 was low, and women with ethnic minority background, multiparity, high body fat percentage and few physically active friends had increased probability of non-compliance. The prognostic model showed fair performance in discriminating between women who did comply and those who did not comply with the PA guideline.

A nested case-control study: personal, social and environmental correlates of vigorous physical activity in adolescents with asthma.

OBJECTIVE: Physical activity (PA) is associated with health benefits. Children and adolescents with asthma may be limited in their PA, particularly at vigorous intensity due to asthma symptoms or poor psychological adjustment to asthma. We aimed to investigate if self-perceived competence, enjoyment, support from others and social-physical environment were associated with vigorous physical activity (VPA) and secondarily to assess if such associations were modified by asthma and asthma severity. METHODS: Data from a nested case-control study at 13 years of age within the birth-cohort Environment and Childhood Asthma Study were compiled from 95 participants with and 79 without asthma. The participants completed a questionnaire designed to capture self-perceived competence, enjoyment, support from others and social-physical environment. VPA, defined as ≥ 6 Metabolic Equivalents, was recorded objectively by SenseWear™ Pro2 Armband. Asthma severity was assessed pragmatically by lung function and use of inhaled glucocorticosteroids and ß2-agonists and incidence of exacerbations in the last 14 days. Data were analysed using linear regression analysis. RESULTS: No significant differences between adolescents with and without asthma were identified in terms of VPA, competence-enjoyment, support from others and social-physical environment. Peer support (b = 0.29 (0.05-0.52)) and competence-enjoyment (b = 0.23 (0.01-0.44)) were significantly and positively associated with VPA, and teacher support (b = -0.26 (-0.50 to -0.02)) were inversely associated. The model explained 25% of the variance in VPA. CONCLUSIONS: Peer support and competence-enjoyment were positively associated with increased VPN in adolescents irrespectively of asthma and asthma severity.

Are weight-related attitudes and behaviours associated with the accuracy of BMI derived from self-reported weight and height among 13-year-olds?

AIMS: The aim was to explore the association between weight-related attitudes and behaviours and the accuracy of body mass index (BMI) derived from self-reported weight and height. METHODS: A total of 828 adolescents from the Health In Adolescents study were included. Self-reported and objective weight and height data were collected, and BMI was computed. Information about weight-related attitudes and behaviours was obtained. The association between weight-related attitudes and behaviours and the difference between BMI computed from self-reported and objective measures was assessed using generalized linear mixed model analyses. RESULTS: BMI was under-reported by overweight girls (p<0.001) and boys (p<0.001) compared to their normal weight counterparts. Underweight girls on the other hand over-reported their BMI (p=0.002). Girls who reported trying to lose weight under-reported their BMI compared to girls who had not tried to do anything about their weight (p=0.02). Girls who perceived their weight as being too much under-reported their BMI compared to girls who thought their weight was ok, the association was however borderline significant (p=0.06); this association was also found among boys (p=0.03). Self-weighing and the reported importance of weight for how adolescents perceive themselves were not associated with the accuracy of BMI. CONCLUSIONS: weight perception and weight control behaviour among girls only were related to the accuracy of self-reported BMI; no association was found with self-weighing behaviour and the perceived importance of weight for how adolescents perceive themselves. Knowledge of such factors will allow for a better interpretation and possibly adjustment/correction of results of surveys based on self-reported weight and height data.

Targeting and tailoring an intervention for adolescents who are overweight: some ethical concerns.

There are important ethical issues to be examined before launching any public health intervention, particularly when targeting vulnerable groups. The aim of this article is to identify and discuss ethical concerns that may arise when intervening for health behavior change among adolescents identified as overweight. These concerns originate from an intervention designed to capacitate adolescents to increase self-determined physical activity. Utilizing an ethical framework for prevention of overweight and obesity, we identified three ethical aspects as particularly significant: the attribution of responsibility for health behavior, liberty to choose, and the effect on the participants' psychosocial well-being. It is discussed whether and how measures can be taken to deal with these aspects. It seems evident that the ethical aspects are mainly concerned with the vulnerability of adolescents identified as overweight. However, we claim that when individual feedback and counseling is provided, tailored interventions have a unique potential to empower adolescents to make ethically anchored decisions about their own health behavior.

The relationship between fitness and health-related quality of life and the mediating role of self-determined motivation in overweight adolescents.

AIM: To examine the relationship between cardiorespiratory fitness (CRF) and health-related quality of life (HRQoL) among overweight adolescents and to test whether this relationship is mediated by body image (BI) and self-determined motivation for physical activity (PA) and exercise. METHODS: One hundred and twenty adolescents identified as overweight or obese were recruited through the school health service. The participants completed self-report instruments measuring HRQoL, BI and self-determined motivation for physical activity and exercise in addition to a 20 m shuttle-run test, and body mass index was calculated. Confirmatory factor analysis was conducted to evaluate the hypothesised five-dimensional structure of the Behavioural Regulation in Exercise Questionnaire-2 (BREQ-2) used to measure self-determined motivation. Associations between the study variables were explored using univariate linear regression. Mediation was tested by a multistage regression approach. RESULTS: The five-dimensional model of BREQ-2 showed acceptable fit for the data. We revealed a statistically significant association between cardiorespiratory fitness and HRQoL (4.16 [0.3-8.02]; p < .05). CRF failed to affect BI in the first mediation equation. Hence, body image was excluded from further analyses. However, self-determined motivation proved to mediate the relationship between CRF and HRQoL. CONCLUSIONS: The results of this study suggest that the motivational mechanisms related to fitness can contribute to explain the association between CRF and HRQoL in overweight adolescents. The findings are important from a public health point of view and should be taken into account in the development of PA interventions for overweight and obese adolescents for the potential enhancement of their physical and psychosocial well-being.

Post-intervention effects on screen behaviours and mediating effect of parental regulation: the HEalth In Adolescents study--a multi-component school-based randomized controlled trial.

BACKGROUND: To improve effectiveness of future screen behaviour interventions, one needs to know whether an intervention works via the proposed mediating mechanisms and whether the intervention is equally effective among subgroups. Parental regulation is identified as a consistent correlate of screen behaviours, but prospective evidence as well as the mediation role of parental regulation is largely lacking. This study investigated post-intervention main effects on screen behaviours in the HEIA-intervention--a Norwegian school-based multiple-behaviour study, as well as mediation effects of parental regulation by adolescents' and parents' report. In addition, moderating effects of gender and weight status on the intervention and mediating effects were explored. METHODS: Participating schools were randomized to control (n=25) or intervention (n=12) condition. Adolescents (n=908 Control; 510 Intervention) self-reported their weekday and weekend TV-viewing and computer/game-use. Change in adolescents' behaviours was targeted through school and parents. Adolescents, mothers (n=591 Control; 244 Interventions) and fathers (n=469 Control; 199 Intervention) reported parental regulation of the screen behaviours post-intervention (at 20 month). The product-of-coefficient test using linear regression analysis was conducted to examine main and mediating effects. RESULTS: There was no intervention effect on the screen behaviours in the total sample. Gender moderated effect on weekend computer/game-use, while weight status moderated the effect on weekday TV-viewing and computer/game-use. Stratified analyses showed a small favourable intervention effect on weekday TV-viewing among the normal weight. Parental regulation did not mediate change in the screen behaviours. However, stronger parental regulation was associated with less TV-viewing and computer/game-use with effects being conditional on adolescents' versus parental reports. Parental regulation of the screen behaviours, primarily by the parental report, was associated with change in the respective behaviours. CONCLUSION: Multiple behaviour intervention may not affect all equally well, and the effect may differ by weight status and gender. In future interventions parents should be encouraged to regulate their adolescents' TV-viewing and computer/game-use on both weekdays and weekends as parental regulation was identified as a determinant of these screen behaviours. However, future intervention studies may need to search for more effective intervention strategies targeting parental regulation. TRIAL REGISTRATION: Current Controlled Trials ISRCTN98552879.

Effects of a 20-month cluster randomised controlled school-based intervention trial on BMI of school-aged boys and girls: the HEIA study.

BACKGROUND: School-based interventions that target prevention of overweight and obesity in children have been tested with mixed results. Thus, successful interventions are still called for. The aim of the present study was to investigate effects of a multicomponent school-based intervention programme targeting physical activity, sedentary and dietary behaviours on anthropometric outcomes. METHODS: A 20-month intervention was evaluated in a cluster randomised, controlled study of 1324 11-year-olds. Outcome variables were body mass index (BMI), BMI-for-age z-score (BMIz), waist circumference (WC), waist-to-height ratio (WTHR) and weight status (International Obesity Task Force's cut-offs). Weight, height and WC were measured objectively; pubertal status was self-reported and parental education was self-reported by the parents. Intervention effects were determined by one-way analysis of covariance and logistic regression, after checking for clustering effects of school, and moderating effects of gender, pubertal status and parental education. RESULTS: Beneficial effects were found for BMI (p=0.02) and BMIz (p=0.003) in girls, but not in boys. While a beneficial effect was found for BMI (p=0.03) in participants of parents reporting a high level of education, a negative effect was found for WTHR in participants with parents reporting a low level of education (p=0.003). There were no intervention effects for WC and weight status. CONCLUSIONS: A multicomponent 20-month school-based intervention had a beneficial effect on BMI and BMIz in adolescent girls, but not in boys. Furthermore, children of higher educated parents seemed to benefit more from the intervention, and this needs attention in future interventions to avoid further increase in social inequalities in overweight and obesity.

A 1-year follow-up of effects of exercise programs on well-being in older adults.

PURPOSE: The purpose of this study was to investigate the long-term effects of three types of training on wellbeing and frequency of physical activity and to determine whether preintervention motivation moderates the effects. METHODS: Sixty-two older adults (M = 75 years old, SD = 5; 61% women) completed 4-mo programs of endurance, functional or strength training, with reassessment of well-being (life satisfaction, positive affect, negative affect, vitality) and physical activity 12 mo later. RESULTS: All groups showed small improvements in most measures of well-being at 4 mo. At follow-up, endurance training still had small beneficial effects, while changes with functional and strength training were generally trivial or harmful. Analysis for moderators indicated that autonomously motivated individuals better maintained gains in well-being and had higher frequencies of physical activity at follow-up compared with controlled individuals. CONCLUSION: Endurance training is recommended for older adults, but the long-term outcomes depend on the individual's motivational regulation at commencement.

The role of gender in the relationship between physical activity, appearance evaluation and psychological distress.

BACKGROUND: Based on previous research, the aim of this cross-sectional study was to examine the indirect effect of physical activity on psychological distress through appearance evaluation. The indirect effect was hypothesized to be conditional on gender, with the effect being more profound among females than among males. METHOD: A total of 2055 adolescents (Mage  = 15.3) completed a self-report questionnaire. RESULTS: Physical activity was indirectly related to psychological distress through appearance evaluation in both males and females, but the indirect effect was stronger for females than for males. CONCLUSIONS: Physical activity may prevent distress through enhanced appearance evaluation.

Supplement usage and doping attitudes in elite youth sports: The mediating role of dietary supplement acceptance.

This study investigated whether dietary supplement acceptance mediated the relationship between supplement use and doping attitudes in youth sports. To this end, we employed a two-wave half-longitudinal design during a sports season (time point one [T1] to time point two [T2]). The sample consisted of 217 elite youth athletes (47% male; mean age = 16.98 years, standard deviation = 0.88) who competed in team sports (43%; N = 93; basketball, floorball, handball, and ice hockey) and individual sports (57%; N = 124; alpine skiing, biathlon, cross-country skiing, swimming, and tennis). The participants were recruited from eight Norwegian sports academy high schools that provide extracurricular, higher-level training and specialization for youth athletes. Results from structural equation modeling analysis indicated that dietary supplement acceptance (T2) mediated the positive relationship between supplement use (T1) and doping attitudes (T2) when accounting for prior levels of the mediator and the outcome variable. These findings suggest that when young athletes used dietary supplements at the start of the season to improve their performance, they were more likely to view the use of supplements as acceptable and to report more favorable attitudes toward doping at the end of the season six months later. For those seeking to prevent doping in youth sports, targeting athletes' views on the acceptable use of dietary supplements may be important.

The relationship between young football players' psychological health resources and the psychological quality of their football experiences: A cross-sectional study.

Studies taking a person-centred statistical approach when examining young peoples` psychological experiences in sport is scarce. The main aim of the present study was to examine the relationships between young football players' psychological health resources and the psychological quality of their football-specific experiences. Data for this cross-sectional study was collected as part of the [BLINDED] arm of the larger Promoting Adolescence Physical Activity (PAPA) multi-centre project [1]. The sample consisted of young [BLINDED] male (n = 814), female (n = 576), grassroots football players between the ages of 10 and 15 years (M = 12.5 years, SD = 1.1 years). We performed a latent profile analysis using Mplus 8.4 using a robust maximum likelihood estimator (MLR). Players with the most resourceful psychological health profile experienced more coach social support (mean = 4.38) than did those with a less well-off resourceful profile (mean = 3.79) and those with the least well-off profile (mean = 3.28). Players with the most resourceful profile also felt a stronger sense of unity among their teammates and they enjoyed football more than those least well off (mean = 4.43 vrs. mean = 3.12 and mean = 4.74 vrs 3.50. respectively). Parallel between-profile differences were also found for the players' general health resources including perceived life satisfaction, general health and family affluence as covariates. Findings suggest that variations in young players' psychological health profiles and their general health resources play a role in the quality of their football-specific psychological experiences.

Effects of a staff physical activity professional development intervention on preschoolers' mental health and self-regulation: The active learning Norwegian Preschool(er)s (ACTNOW) cluster randomised controlled trial.

BACKGROUND AND AIM: Physical activity may have positive effects on preschoolers' mental health and self-regulation. The preschool setting provides children with opportunities to meet physical activity guidelines and could improve with staff training in delivering physical activity. This study examined the effect of physical activity professional development for preschool staff on preschoolers' proxy-measured mental health and self-regulation. METHODS: In total, 1265 children from 46 preschools were cluster randomised to either the intervention or the control group. The intervention was nested within two levels implemented concurrently: the preschool level, formed as a professional development where preschools conducted development work, and the child level, with whom the staff implemented physical activity with four core components. Data were analysed using an ANCOVA model through structural equation modelling with latent outcome factors of: emotional problems, peer problems, hyperactivity, and prosocial behaviour from the Strength and Difficulties Questionnaire; and cognitive, emotional, and behavioural self-regulation from the Child Self-regulation and Behaviour Questionnaire. RESULTS: No effects of the intervention (standardised effect sizes -0.195-0.145, p-values 0.118-0.893) were observed. Secondary analysis showed that children with initially high prosocial behaviour and behavioural self-regulation positively benefited from the intervention (p = 0.035 and p = 0.047, respectively). CONCLUSION: The ACTNOW intervention had no effects on preschoolers' mental health or self-regulation after 18 months, besides effects for children with initially the highest prosocial behaviour and behavioural self-regulation. Although the professional development was more extensive than previous studies it may have been insufficient to change the preschools physical activity practices. CLINICAL TRIAL REGISTRATION: www. CLINICALTRIALS: gov identifier NCT04048967.

Intervention effects on physical activity: the HEIA study - a cluster randomized controlled trial.

BACKGROUND: Although school-based interventions to promote physical activity in adolescents have been suggested in several recent reviews, questions have been raised regarding the effects of the strategies and the methodology applied and for whom the interventions are effective. The aim of the present study was to investigate effects of a school-based intervention program: the HEalth in Adolescents (HEIA) study, on change in physical activity, and furthermore, to explore whether potential effects varied by gender, weight status, initial physical activity level and parental education level. METHODS: This was a cluster randomized controlled 20 month intervention study which included 700 11-year-olds. Main outcome-variable was mean count per minute (cpm) derived from ActiGraph accelerometers (Model 7164/GT1M). Weight and height were measured objectively. Adolescents reported their pubertal status in a questionnaire and parents reported their education level on the consent form. Linear mixed models were used to test intervention effects and to account for the clustering effect of sampling by school. RESULTS: The present study showed an intervention effect on overall physical activity at the level of p=0.05 with a net effect of 50 cpm increase from baseline to post intervention in favour of the intervention group (95% CI -0.4, 100). Subgroup analyses showed that the effect appeared to be more profound among girls (Est 65 cpm, CI 5, 124, p=0.03) and among participants in the low-activity group (Est 92 cpm, CI 41, 142, p<0.001), as compared to boys and participants in the high-activity group, respectively. Furthermore, the intervention affected physical activity among the normal weight group more positively than among the overweight, and participants with parents having 13-16 years of education more positively than participants with parents having either a lower or higher number of years of education. The intervention seemed to succeed in reducing time spent sedentary among girls but not among boys. CONCLUSIONS: A comprehensive but feasible, multi-component school-based intervention can affect physical activity patterns in adolescents by increasing overall physical activity. This intervention effect seemed to be more profound in girls than boys, low-active adolescents compared to high-active adolescents, participants with normal weight compared to the overweight, and for participants with parents of middle education level as opposed to those with high and low education levels, respectively. An implementation of the HEIA intervention components in the school system may have a beneficial effect on public health by increasing overall physical activity among adolescents and possibly among girls and low-active adolescents in particular.