Individual Differences in Exercise Behavior: Stability and Change in Genetic and Environmental Determinants From Age 7 to 18

Cluster profiles of distressing psychotic-like experiences among children and associations with genetic risk, prenatal cannabis exposure, and social-environmental characteristics

BACKGROUND

Distressing psychotic-like experiences (PLEs) in children are associated with an increased risk for psychiatric disorders. Recent studies suggest that different domains of psychotic symptoms could be associated with distinct risk factors, but less is known about PLEs. This study clustered PLEs into subgroups and explored the genetic and environmental characteristics associated with these profiles.

METHODS

Data from children (N = 11,854) recruited as part of the Adolescent Brain and Cognitive Development Study v5.1 assessed PLEs using 21-items from the Prodromal-Questionnaire-Brief Child Version. K-medoid clustering of PLEs was conducted among children with at least one distressing PLE item at baseline (n = 3155). Associations of polygenic risk scores for schizophrenia (PRS-SCZ) and social-environmental characteristics with PLE subgroups were estimated using generalized multinomial mixed models, adjusting for age, sex, race/ethnicity, parental education, income-to-needs ratio, and family history of psychosis.

RESULTS

We identified three distressing PLE subgroups: hallucinatory-like (n = 1110), paranoid-like (n = 1229), and multiple PLE domains (n = 816). Compared to those without any distressing PLEs (n = 8699), those with hallucinatory-like PLE were more likely to have had prenatal cannabis exposure (Odds Ratio (OR) = 1.578, 95 % CI: 1.231-2.023); paranoid-like individuals had higher PRS-SCZ (OR = 1.080, 95 % CI: 1.001-1.166); those with multiple PLE domains participated in less physical activities (OR = 0.880, 95 % CI: 0.803-0.964). All groups were more likely to have experienced greater childhood adversity and worse school environments.

CONCLUSIONS

We found that those with different aspects of distressing PLEs had distinct and similar genetic and environmental characteristics. These results suggest that it may be important to consider the heterogeneity of PLE in conceptualizing the development of psychosis.

Exercise addiction in college students: the impact of body dissatisfaction, stress, physical activity and gender

Introduction

Engaging in physical activity is commonly regarded as beneficial to health. However, exercise addiction may arise when enthusiasm for exercise reaches a level that disrupts life balance and overall well-being. Factors influencing college students' exercise addiction remain largely unknown.

Methods

Participants aged 18-23 years (N = 384) underwent body measurements, and sex-adapted silhouettes were employed to assess their level of body dissatisfaction. The Exercise Addiction Inventory was used to investigate the level of exercise addiction among college students. We used t-tests to compare sex differences in BMI, body fat percentage, body dissatisfaction levels, stress levels, and exercise addiction among college students. Chi-square's test was used to compare differences between males and females in terms of BMI, physical activity levels, stress, and exercise addiction ratings. The exercise addiction level of college students was used as the dependent variable in multiple regression analysis, and BMI, muscle mass, body fat percentage, exercise score, stress level score, and body dissatisfaction level score were used as predictors.

Results

The results of multivariate regression analysis revealed sex differences in physical activity scores, stress levels, body dissatisfaction, and exercise addiction levels, with males consistently exhibiting significantly higher scores than females. In males, body dissatisfaction scores and stress were significant predictors of exercise addiction. Among females, physical activity scores, stress, body dissatisfaction, and body fat percentage were identified as significant predictors of exercise addiction.

Discussion

College students confront risks in relation to exercise addiction. High stress levels and body dissatisfaction may be important causes of exercise addiction. The male students had higher body dissatisfaction, stress levels, and risk of exercise addiction than the female students. With a change in female bodily aesthetics in terms of a shift from a primary focus on thinness-related beauty to having a thin and toned body, the risk of exercise addiction in female college students may increase.

Happy children! A network of psychological and environmental factors associated with the development of positive affect in 9-13 children

To deepen the development of positive affect during early adolescence and shed new light on its predictors, this study adopts an exploratory network approach to first identify the main domains that describe the variability of children's psychological, environmental, and behavioral characteristics, and then use these domains to longitudinally predict positive affect and its development within a latent growth framework. To this aim, we considered 10,904 US participants (9 years old at baseline; 13 years old 42 months later), six measurement occasions of positive affect, and 46 baseline indicators from the ABCD study. Our results not only confirm that positive affect declines between 9 and 13 years old, but also show that among the five domains identified (behavioral dysregulation, cognitive functioning, psychological problems, supportive social environment, and extracurricular activities), only a supportive social environment consistently predicts positive affect. This is crucial for practitioners and policymakers, as it can help them focus on the elements within our complex network of psychological, social, and environmental variability.

Associations Between Genetic Risk, Physical Activities, and Distressing Psychotic-like Experiences

BACKGROUND AND HYPOTHESIS

Persistent distressing psychotic-like experiences (PLE) are associated with impaired functioning and future psychopathology. Prior research suggests that physical activities may be protective against psychopathology. However, it is unclear whether physical activities may interact with genetics in the development of psychosis.

STUDY DESIGN

This study included 4679 participants of European ancestry from the Adolescent Brain Cognitive Development Study. Persistent distressing PLE was derived from the Prodromal-Questionnaire-Brief Child Version using four years of data. Generalized linear mixed models tested the association between polygenic risk score for schizophrenia (PRS-SCZ), physical activities, and PLE. The models adjusted for age, sex, parental education, income-to-needs ratio, family history of psychosis, body mass index, puberty status, principal components for PRS-SCZ, study site, and family.

STUDY RESULTS

PRS-SCZ was associated with a greater risk for persistent distressing PLE (adjusted relative risk ratio (RRR) = 1.14, 95% CI [1.04, 1.24], P = .003). Physical activity was associated with less risk for persistent distressing PLE (adjusted RRR = 0.87, 95% CI [0.79, 0.96], P = .008). Moreover, physical activities moderated the association between PRS-SCZ and persistent distressing PLE (adjusted RRR = 0.89, 95% CI [0.81, 0.98], P = .015), such that the association was weaker as participants had greater participation in physical activities.

CONCLUSIONS

These findings demonstrate that the interaction between genetic liability and physical activities is associated with trajectories of distressing PLE. Further research is needed to understand the mechanisms of physical activities and genetic liability for schizophrenia in the development of psychosis.

Genetic confounding in the association of early motor development with childhood and adolescent exercise behavior

INTRODUCTION

Early motor development has been found to be a predictor of exercise behavior in children and adolescents, but whether this reflects a causal effect or confounding by genetic or shared environmental factors remains to be established.

METHODS

For 20,911 complete twin pairs from the Netherlands Twin Register a motor development score was obtained from maternal reports on the timing of five motor milestones. During a 12-year follow-up, subsamples of the mothers reported on the twins' ability to perform seven gross motor skills ability (N = 17,189 pairs), and weekly minutes of total metabolic equivalents of task (MET) spent on sports and exercise activities at age 7 (N = 3632 pairs), age 10 (N = 3735 pairs), age 12 (N = 7043 pairs), and age 14 (N = 3990 pairs). Multivariate phenotypic and genetic regression analyses were used to establish the predictive strength of the two motor development traits for future exercise behavior, the contribution of genetic and shared environmental factors to the variance in all traits, and the contribution of familial confounding to the phenotypic prediction.

RESULTS

Significant heritability (h2) and shared environmental (c2) effects were found for early motor development in boys and girls (h2 = 43-65%; c2 = 16-48%). For exercise behavior, genetic influences increased with age (boys: h2age7 = 22% to h2age14 = 51%; girls: h2age7 = 3% to h2age14 = 18%) paired to a parallel decrease in the influence of the shared environment (boys: c2age7 = 68% to c2age14 = 19%; girls: c2age7 = 80% to c2age14 = 48%). Early motor development explained 4.3% (p < 0.001) of the variance in future exercise behavior in boys but only 1.9% (p < 0.001) in girls. If the effect in boys was due to a causal effect of motor development on exercise behavior, all of the factors influencing motor development would, through the causal chain, also influence future exercise behavior. Instead, only the genetic parts of the regression of exercise behavior on motor development were significant. Shared and unique environmental parts of the regression were largely non-significant, which is at odds with the causal hypothesis.

CONCLUSION

No support was found for a direct causal effect in the association between rapid early motor development on future exercise behavior. In boys, early motor development appears to be an expression of the same genetic factors that underlie the heritability of childhood and early adolescent exercise behavior.

Negative impact of daily screen use on inhibitory control network in preadolescence: A two-year follow-up study

The COVID-19 pandemic has made an unprecedented shift in children's daily lives. Children are increasingly spending time with screens to learn and connect with others. As the online environment rapidly substitutes in-person experience, understanding children's neuropsychological trajectories associated with screen experiences is important. Previous findings suggest that excessive screen use can lead children to prefer more immediate rewards over delayed outcomes. We hypothesized that increased screen time delays a child's development of inhibitory control system in the brain (i.e., fronto-striatal circuitry). By analyzing neuropsychological data from 8324 children (9-11ys) from the ABCD Study, we found that children who had more screen time showed a higher reward orientation and weaker fronto-striatal connectivity. Importantly, we found that the daily screen exposure mediated the effect of reward sensitivity on the development of the inhibitory control system in the brain over a two year period. These findings suggest possible negative long-term impacts of increased daily screen time on children's neuropsychological development. The results further demonstrated that screen time influences dorsal striatum connectivity, which suggests that the effect of daily screen use is a habitual seeking behavior. The study provides neural and behavioral evidence for the negative impact of daily screen use on developing children.

Genetic and Environmental Variation in Continuous Phenotypes in the ABCD Study®

Twin studies yield valuable insights into the sources of variation, covariation and causation in human traits. The ABCD Study® (abcdstudy.org) was designed to take advantage of four universities known for their twin research, neuroimaging, population-based sampling, and expertise in genetic epidemiology so that representative twin studies could be performed. In this paper we use the twin data to: (i) provide initial estimates of heritability for the wide range of phenotypes assessed in the ABCD Study using a consistent direct variance estimation approach, assuring that both data and methodology are sound; and (ii) provide an online resource for researchers that can serve as a reference point for future behavior genetic studies of this publicly available dataset. Data were analyzed from 772 pairs of twins aged 9-10 years at study inception, with zygosity determined using genotypic data, recruited and assessed at four twin hub sites. The online tool provides twin correlations and both standardized and unstandardized estimates of additive genetic, and environmental variation for 14,500 continuously distributed phenotypic features, including: structural and functional neuroimaging, neurocognition, personality, psychopathology, substance use propensity, physical, and environmental trait variables. The estimates were obtained using an unconstrained variance approach, so they can be incorporated directly into meta-analyses without upwardly biasing aggregate estimates. The results indicated broad consistency with prior literature where available and provided novel estimates for phenotypes without prior twin studies or those assessed at different ages. Effects of site, self-identified race/ethnicity, age and sex were statistically controlled. Results from genetic modeling of all 53,172 continuous variables, including 38,672 functional MRI variables, will be accessible via the user-friendly open-access web interface we have established, and will be updated as new data are released from the ABCD Study. This paper provides an overview of the initial results from the twin study embedded within the ABCD Study, an introduction to the primary research domains in the ABCD study and twin methodology, and an evaluation of the initial findings with a focus on data quality and suitability for future behavior genetic studies using the ABCD dataset. The broad introductory material is provided in recognition of the multidisciplinary appeal of the ABCD Study. While this paper focuses on univariate analyses, we emphasize the opportunities for multivariate, developmental and causal analyses, as well as those evaluating heterogeneity by key moderators such as sex, demographic factors and genetic background.

Genetic Pathways Underlying Individual Differences in Regular Physical Activity

Twin and family studies show a strong contribution of genetic factors to physical activity (PA) assessed by either self-report or accelerometers. PA heritability is around 43% across the lifespan. Genome-wide association studies have implied biological pathways related to exercise ability and enjoyment. A polygenic score based on genetic variants influencing PA could help improve the success of intervention programs.

Associations of parental physical activity trajectories with offspring's physical activity patterns from childhood to middle adulthood: The Young Finns Study

We investigated the association of parental physical activity (PA) trajectories with offspring's youth and adult PA. Self-reported PA data were extracted from the Young Finns Study with three follow-ups for parents between 1980 and 1986 and nine follow-ups for their offspring in youth between 1980 and 2011 (aged 9-39 years, n = 2402) and in adulthood in 2018. Accelerometer-derived PA was quantified in 2018-2020 (aged 43-58 years, n = 1134). Data were analyzed using mixture models and conducted in 2022. We identified three trajectories for fathers and mothers (high-stable activity, 20.2%/16.6%; moderate-stable activity, 50.5%/49.6%; and low-stable activity, 29.4%/33.7%) and four for youth male and female offspring (persistently active, 13.4%/5.1%; increasingly active, 32.1%/43.1%; decreasingly active, 14.4%/12.6%; and persistently low-active, 40.1%/39.1%). Compared to low-stable active parents, high-stable active fathers had a higher probability of having their sons and daughters classified as persistently active, increasingly active, and decreasingly active in youth (B_range = 0.50-1.79, all p < 0.008), while high- and moderate-stable active mothers had significantly increased likelihood of having their daughters classified as persistently active and decreasingly active in youth (B_range = 0.63-1.16, all p < 0.009). Fathers' and mothers' high-stable activity was associated with higher self-reported PA of adult offspring than parental low-stable activity. Persistently active and increasingly active offspring in youth accumulated more adult total PA, moderate-to-vigorous PA, step counts, and self-reported PA than persistently low-active ones (all p < 0.036). Parental persistent PA, particularly paternal persistent PA, predicts offspring's PA concurrently and prospectively. Increasing and maintaining PA in youth predicts higher PA levels in midlife.

Genetic and Environmental Effects on the Individual Variation and Continuity of Participation in Diverse Physical Activities

INTRODUCTION

Participation in diverse physical activities has beneficial health effects. However, little is known on how genetic and environmental factors affect this trait. Thus, we examined to what extent these factors explain participation in diverse leisure-time physical activities from late adolescence to adulthood using a twin study design.

METHODS

The participants were Finnish twins who reported their participation in diverse leisure-time physical activities at ages 17 (n = 5429) and 34 yr (n = 4246). The number of physical activities engaged in was analyzed using applications of structural linear modeling for twin data.

RESULTS

On average, the total number of physical activities engaged in during leisure time was slightly over three at both ages and in both sexes, with moderate heritability estimates (40%-58%) from adolescence to adulthood. Environmental factors shared by co-twins (e.g., childhood family environment) influenced only in adolescence, being higher for women. Environmental influences unique to each co-twin explained the remaining variances (34%-57%), being higher at age 34 yr. Participation in diverse leisure-time physical activities correlated moderately between ages 17 and 34 yr (men: rtrait = 0.30, 95% confidence interval [CI] = 0.25-0.35; women: rtrait = 0.26, 95% CI = 0.22-0.31). In addition, genetic influences on participation in physical activities correlated moderately between adolescence and adulthood (rA = 0.51, 95% CI = 0.39-0.64, and 0.44, 95% CI = 0.34-0.55, respectively). These common genetic influences explained 93% of the trait correlations found in men and 85% in women.

CONCLUSIONS

Genetic and unique environmental influences explain a large proportion of variation in the number of leisure-time physical activities. However, the estimates vary by age and sex. Common genetic background mainly explains the continuity of the participation in diverse leisure-time physical activities between adolescence and adulthood.

A Comprehensive Overview of the Physical Health of the Adolescent Brain Cognitive Development Study Cohort at Baseline

Physical health in childhood is crucial for neurobiological as well as overall development, and can shape long-term outcomes into adulthood. The landmark, longitudinal Adolescent Brain Cognitive Development StudySM (ABCD study®), was designed to investigate brain development and health in almost 12,000 youth who were recruited when they were 9-10 years old and will be followed through adolescence and early adulthood. The overall goal of this paper is to provide descriptive analyses of physical health measures in the ABCD study at baseline, including but not limited to sleep, physical activity and sports involvement, and body mass index. Further this summary will describe how physical health measures collected from the ABCD cohort compare with current normative data and clinical guidelines. We propose this data set has the potential to facilitate clinical recommendations and inform national standards of physical health in this age group. This manuscript will also provide important information for ABCD users and help guide analyses investigating physical health including new avenues for health disparity research as it pertains to adolescent and young adult development.

Extracurricular Activities, Screen Media Activity, and Sleep May Be Modifiable Factors Related to Children's Cognitive Functioning: Evidence From the ABCD Study®

This study used a machine learning framework in conjunction with a large battery of measures from 9,718 school-age children (ages 9-11) from the Adolescent Brain Cognitive DevelopmentSM (ABCD) Study to identify factors associated with fluid cognitive functioning (FCF), or the capacity to learn, solve problems, and adapt to novel situations. The identified algorithm explained 14.74% of the variance in FCF, replicating previously reported socioeconomic and mental health contributors to FCF, and adding novel and potentially modifiable contributors, including extracurricular involvement, screen media activity, and sleep duration. Pragmatic interventions targeting these contributors may enhance cognitive performance and protect against their negative impact on FCF in children.

Maternal Education and Academic Achievement in Schoolchildren: The Role of Cardiorespiratory Fitness

OBJECTIVES

To examine the relationship between maternal education, cardiorespiratory fitness, and academic achievement in schoolchildren, specifically whether the association between maternal education and academic achievement is mediated by cardiorespiratory fitness.

STUDY DESIGN

This is a secondary analysis of a cross-sectional study including 478 Spanish schoolchildren aged 8-11 years. ANOVA was used to test differences in cardiorespiratory fitness by maternal education level. ANCOVA was used to test the differences in academic achievement by the educational level of mothers and the cardiorespiratory fitness of children, controlling for each other. A mediation analysis was used to test if the relationship between maternal education and academic achievement was explained by cardiorespiratory fitness.

RESULTS

A higher level of maternal education was associated with a higher cardiorespiratory fitness level and academic achievement in children; moreover, the cardiorespiratory fitness level in children was associated with better academic achievement (P < .05). Finally, cardiorespiratory fitness acted as a partial mediator of the relationship between maternal education and academic achievement in boys (z = 1.81; P = .03) but not in girls (z = 0.86; P = .19), explaining 6.54% of this relationship for the total sample and 6.67% for boys.

CONCLUSIONS

This study suggests that the benefits of maternal education on academic achievement are partially explained by the mediating role of cardiorespiratory fitness.

Screen media activity does not displace other recreational activities among 9-10 year-old youth: a cross-sectional ABCD study®

Background

Screen media is among the most common recreational activities engaged in by children. The displacement hypothesis predicts that increased time spent on screen media activity (SMA) may be at the expense of engagement with other recreational activities, such as sport, music, and art. This study examined associations between non-educational SMA and recreational activity endorsement in 9–10-year-olds, when accounting for other individual (i.e., cognition, psychopathology), interpersonal (i.e., social environment), and sociodemographic characteristics.

Methods

Participants were 9254 youth from the Adolescent Brain Cognitive Development Study®. Latent factors reflecting SMA, cognition, psychopathology, and social environment were entered as independent variables into logistic mixed models. Sociodemographic covariates included age, sex, race/ethnicity, education, marital status, and household income. Outcome variables included any recreational activity endorsement (of 19 assessed), and specific sport (swimming, soccer, baseball) and hobby (music, art) endorsements.

Results

In unadjusted groupwise comparisons, youth who spent more time engaging with SMA were less likely to engage with other recreational activities (ps < .001). However, when variance in cognition, psychopathology, social environment, and sociodemographic covariates were accounted for, most forms of SMA were no longer significantly associated with recreational activity engagement (p > .05). Some marginal effects were observed: for every one SD increase in time spent on games and movies over more social forms of media, youth were at lower odds of engaging in recreational activities (adjusted odds ratio = 0·83, 95% CI 0·76–0·89). Likewise, greater general SMA was associated with lower odds of endorsing group-based sports, including soccer (0·93, 0·88–0·98) and baseball (0·92, 0·86–0·98). Model fit comparisons indicated that sociodemographic characteristics, particularly socio-economic status, explained more variance in rates of recreational activity engagement than SMA and other latent factors. Notably, youth from higher socio-economic families were up to 5·63 (3·83–8·29) times more likely to engage in recreational activities than youth from lower socio-economic backgrounds.

Conclusions

Results did not suggest that SMA largely displaces engagement in other recreational activities among 9–10-year-olds. Instead, socio-economic factors greatly contribute to rates of engagement. These findings are important considering recent shifts in time spent on SMA in childhood.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-020-09894-w.

The importance of social factors in the association between physical activity and depression in children

BACKGROUND

Physical activity is associated with reduced depression in youth and adults. However, our understanding of how different aspects of youth activities-specifically, the degree to which they are social, team-oriented, and physical-relate to mental health in children is less clear.

METHODS

Here we use a data-driven approach to characterize the degree to which physical and non-physical youth activities are social and team-oriented. We then examine the relationship between depressive symptoms and participation in different clusters of youth activities using mixed effect models and causal mediation analyses in 11,875 children from the Adolescent Brain Cognitive Development (ABCD) Study. We test our hypotheses in an original sample (n = 4520, NDA release 1.1) and replication sample of participants (n = 7355, NDA release 2.0.1).

RESULTS

We show and replicate that social-physical activities are associated with lower depressive symptoms. Next, we demonstrate that social connections, measured by number of close friends, partially mediate the association between social-physical activities and lower depressive symptoms.

CONCLUSIONS

Our results provide a rubric for using data-driven techniques to investigate different aspects of youth activities and highlight the social dynamics of physical activities as a possible protective factor against depression in childhood.

Bullying Environment Moderates the Relationship Between Exercise and Mental Health in Bullied US Children

BACKGROUND

Exercise reduces the odds of sadness and suicidality in bullied students, but the role of the bullying environment on this relationship remains unknown.

METHODS

Using combined data from the 2013 and 2015 Youth Risk Behavior Survey (N = 29,207), adjusted logistic regression models estimated odds ratios between exercise, sadness, and suicidal ideation and attempt, stratified by bullying exposure (electronically/at school).

RESULTS

Overall, 40.2% of students bullied at school and 48.3% of students bullied electronically reported feeling sad, compared to 22.6% of those not bullied. Bullied students were 2-3 times more likely to report suicidal ideation, and 3-4 times more likely to report suicidal attempt, regardless of bullying context. Students who were bullied at school and exercised 4-7 days per week had lower odds of sadness (adjusted odds ratio [AOR]: 0.64; 95% confidence interval [CI]: 0.51-0.81), suicidal ideation (AOR: 0.66; 95% CI: 0.53-82), and suicidal attempt (AOR: 0.69; 95% CI: 0.48-0.98) compared to those who exercised 0-3 days. There were no protective effects of exercise for students bullied electronically.

CONCLUSIONS

Exercise reduced sadness and suicidality in adolescents bullied at school but not for students who were cyberbullied. Bullying environment should be a primary consideration in school mental health treatment and maintenance paradigms.

An Extended Twin-Pedigree Study of Different Classes of Voluntary Exercise Behavior

We investigated the familial clustering of different classes of voluntary regular exercise behavior in extended twin-family pedigrees. In contrast to the earlier work based on twin data only, this allowed us to estimate the contributions of shared household effects (C), additive (A), and non-additive (D) genetic effects on voluntary exercise behavior. To test whether shared household effects were inflated by assortative mating we examined the causes of spousal resemblance. For adolescent and adult participants (aged 16 to 65) in the Netherlands Twin Register we constructed 19,543 pedigrees which specified all relations among nuclear family members and larger families in the register (N = 50,690 individuals). Data were available on total weekly MET minutes spent on leisure time exercise, and on total weekly MET minutes spent on exercise activities in team-based, solitary, competitive, non-competitive, externally paced and internally paced exercise. We analyzed the data in the Mendel software package (Lange et al. in Bioinformatics 29(12):1568–1570, 2013) under multiple definitions of household sharing and used data from spouses of twins to test phenotypic assortment, social homogamy, and marital interaction as potential sources of spousal resemblance. Results confirmed the influence of genetic factors on the total volume of weekly exercise behavior throughout the life span. Broad sense heritability ranged from 34 to 41% (19–26% A, 12–21% D), and did not depend on the definition for household sharing. Engaging in team-based, competitive, externally paced activities (e.g., soccer) was ~ 13% more heritable than engaging in non-competitive, solitary activities (e.g., jogging). Having shared a household as siblings explained 4–8% of the variance in adult exercise behavior, whereas sharing a household by spouses yielded higher C estimates (20–24%), as it incorporates spousal resemblance. Spousal resemblance was explained by both social homogamy and marital interaction, with little evidence for phenotypic assortment. We conclude that both the amount of voluntary exercise behavior and the preference for specific classes of exercise activities in adults is explained by additive and non-additive genetic factors and unique environmental influences that include correlated exercise behavior of spouses.

Meta-analysis of physical activity and effects of social function and quality of life on the physical activity in patients with schizophrenia

Schizophrenia patients have increased mortality and morbidity, mainly due to premature cardiovascular disease resulting from decreased physical activity (PA). However, which PA intensity is impaired in the patients and how factors such as social function and quality of life (QoL) are related to decreased PA is unknown. To assess PA, social function and QoL, the International Physical Activity Questionnaire (IPAQ), Social Functioning Scale (SFS) and Schizophrenia Quality of Life Scale (SQLS), respectively, were used in 109 schizophrenia patients and 69 healthy subjects. A meta-analysis comparing PA intensities (vigorous, moderate and light) assessed by the single PA measurement between schizophrenia patients and healthy subjects after including our case-control sample was performed. Furthermore, the effects of social function and QoL on each level of PA intensity were investigated in patients and controls. The meta-analysis in 212 schizophrenia patients and 132 healthy subjects revealed that patients showed lower total PA, particularly vigorous PA, than controls (I² = 0, Hedges' g = - 0.41, P = 2.80 × 10^-4). The decreased total PA was correlated with impaired total SFS scores (β = 0.24, P = 2.86 × 10^-3), withdrawal (β = 0.23, P = 3.74 × 10^-3) and recreation (β = 0.23, P = 3.49 × 10^-3) without significant heterogeneity between patients and controls. In contrast, the decreased total PA was affected by low independence-performance (β = 0.22, P = 0.034), employment/occupation (β = 0.27, P = 8.74 × 10^-3), psychosocial (β = - 0.24, P = 0.021) and motivation/energy (β = - 0.26, P = 0.013), but only in patients. Similar findings were obtained for vigorous PA but not moderate or light PA. Our findings suggest that the impaired vigorous PA in schizophrenia patients may be mediated by schizophrenia-specific factors of social functioning and QoL. Understanding these factors has important implications for increasing PA participation in schizophrenia patients.

The Behavioral Medicine Research Council: Its origins, mission, and methods

The Behavioral Medicine Research Council (BMRC) is a new, autonomous joint committee of 4 of the leading behavioral medicine research organizations, including the Academy of Behavioral Medicine Research, the American Psychosomatic Society, the Society for Health Psychology, and the Society of Behavioral Medicine. The BMRC's work has important implications for the science and practice of behavioral medicine. The distinguished senior scientists who comprise this new committee will identify a series of strategic research goals for behavioral medicine and promote systematic, interdisciplinary efforts to achieve them. This special report discusses the developments that led to the formation of the BMRC, describes the BMRC's mission, and explains the methods that its members will use. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Tracking of voluntary exercise behaviour over the lifespan

Background

The aim of many physical activity interventions is to develop life-long habits of regular exercise and sports activities in leisure time. Previous studies that assessed tracking (i.e. the stability of a trait over the lifespan) of leisure time exercise behaviour across various parts of the life span have treated it as a uniform construct by summing all types of leisure time exercise activities into a single summary score for the total volume of exercise. This study provides new insight by additionally determining tracking across leisure time exercise activities in six different domains: (1) team-based versus solitary activities, (2) competitive versus non-competitive activities, and (3) externally paced versus internally paced activities. We also assessed which of the domains of exercise activities best predicted total volume of exercise at follow-up.

Methods

A large dataset (N = 43,889) from the Netherlands Twin Register (NTR) was used to analyse the tracking of exercise behaviour over time. Using this dataset, we were able to examine tracking as a function of baseline age (8 to 80 years) and tracking duration (2 to 22-year follow-up), taking into account sex differences, using generalized estimating equations.

Results

Two-year tracking coefficients are moderate to high for total volume of exercise across ages at baseline, ranging from .38 to .77 with a median of .57. Tracking coefficients tend to decrease as the distance to follow-up increases, down to a median of .38 for the 22-year tracking coefficients. The patterns of tracking were largely domain-independent and were largely similar for solitary, competitive, non-competitive, externally and internally paced activities. With the exception of team-based activities, tracking was seen to increase as a function of baseline age. Cross-domain tracking did not favour any specific domain of exercise activity as the best predictor for total volume of exercise behaviour and this was true at all baseline ages.

Conclusion

We conclude that exercise behaviour is moderately to highly stable across the life span. In particular in adulthood, where the tracking of exercise mimics that of a classical behavioural trait like personality. This stability reinforces existing evidence that exercise habits are hard to change, but at the same time suggests that successful intervention leading to the adoption of exercise habits will tend to last.

Electronic supplementary material

The online version of this article (10.1186/s12966-019-0779-4) contains supplementary material, which is available to authorized users.

Biological/Genetic Regulation of Physical Activity Level: Consensus from GenBioPAC

PURPOSE

Physical activity unquestionably maintains and improves health; however, physical activity levels globally are low and not rising despite all the resources devoted to this goal. Attention in both the research literature and the public policy domain has focused on social-behavioral factors; however, a growing body of literature suggests that biological determinants play a significant role in regulating physical activity levels. For instance, physical activity level, measured in various manners, has a genetic component in both humans and nonhuman animal models. This consensus article, developed as a result of an American College of Sports Medicine-sponsored round table, provides a brief review of the theoretical concepts and existing literature that supports a significant role of genetic and other biological factors in the regulation of physical activity.

CONCLUSIONS

Future research on physical activity regulation should incorporate genetics and other biological determinants of physical activity instead of a sole reliance on social and other environmental determinants.

Predictors of Physical Activity in Middle Childhood. A Fixed-Effects Regression Approach

Background: Moderate-to-vigorous physical activity (MVPA) has a range of health benefits across the life span. Although many putative determinants of children's MVPA have been identified, their causal status is uncertain due to difficulties in adjusting for potential confounders. Objective: To inform promotion of children's MVPA we therefore aimed to examine well-known child-, family- and contextual predictors of MVPA in middle childhood, by applying a fixed effects regression approach, which rules out the influence of all unmeasured time-invariant confounders. Methods: Two birth cohorts of children living in the city of Trondheim, Norway were invited to participate (82.0% consented). The participants were followed-up biennially from age 6 to 10 years (n = 800) between 2009 and 2014. MVPA in children was recorded by accelerometers and child-, family- and contextual factors were obtained through interviews and questionnaires. Predictors included (i) child-level factors: the child's time outdoors, organized sports participation, athletic self-concept, self-reported screen time and objectively measured sedentariness; (ii) family factors: self-reported parental MVPA and actively transporting the child to school; and (iii) contextual factors: parental socio-economic status (SES), access to playgrounds and ballparks, traffic safety, and having a garden. A three-wave prospective study was conducted with a hybrid fixed effects regressions analysis adjusting for all time-invariant confounders to examine predictors of MVPA. Results: Children evidenced increased MVPA when they spent more time outside, spent less time being sedentary and when the family had a garden and lived in a traffic-safe area. Conclusion: Adjusting for measured time-varying and all unmeasured time-invariant confounders renders many previously identified child and family factors without impact on MVPA in children. However, several contextual factors may promote MVPA in middle childhood, and efforts to facilitate children being outside in environments that promote physical activity (e.g., being outside, in gardens, or otherwise traffic safe areas) may prove important.

How Consistent are Genetic Factors in Explaining Leisure-Time Physical Activity and Sport Participation? The Portuguese Healthy Families Study

This study investigates how consistent genetic factors are, as measured by heritability estimates (h2), in the leisure-time physical activity index (LTPAI) and sport participation index (SPI) from early (10-14 yrs) to late adolescence (15-19 yrs). The sample comprises 12,385 subjects from 3,378 Portuguese nuclear families. Height and weight were measured and body mass index (BMI) was calculated, and the LTPAI and SPI were estimated by questionnaire. Socioeconomic status (SES) was assessed by parental occupation. Analyses were done using S.A.G.E. software. Our results showed that h2 estimates for the LTPAI and SPI in the two age groups (10-14 yrs and 15-19 yrs) were stable: for the LTPAI, h2 = 0.297 and 0.322, respectively; and for the SPI, h2 = 0.413 and 0.428, respectively. Sibling correlations and environmental correlations are higher in the younger age group for both the LTPAI and the SPI. Spousal correlations are higher in the younger age group for the LTPAI and lower for the SPI than the older group. Parent-offspring correlations are similar in both age groups for the LTPAI and SPI. In conclusion, the influence of genetic factors on physical activity and sport participation remains stable across age in adolescence. However, variation in sibling correlations - in particular, environmental correlations - was observed. These findings suggest that shared/non-shared environmental factors express different degrees of importance across age. Future intervention programs aiming to promote change in behaviors need to consider these results to bring about positive changes in physical activity and sport participation behaviors within the family setting.

Dopaminergic Genetic Variants and Voluntary Externally Paced Exercise Behavior

PURPOSE

Most candidate gene studies on the neurobiology of voluntary exercise behavior have focused on the dopaminergic signaling pathway and its role in the mesolimbic reward system. We hypothesized that dopaminergic candidate genes may influence exercise behavior through additional effects on executive functioning and that these effects are only detected when the types of exercise activity are taken into account.

METHODS

Data on voluntary exercise behavior and at least one single-nucleotide polymorphism/variable number of tandem repeat (VNTR) were available for 12,929 participants of the Netherlands Twin Registry. Exercise activity was classified as externally paced if a high level of executive function skill was required. The total volume of voluntary exercise (minutes per week) as well as the volume specifically spent on externally paced activities were tested for association with nine functional dopaminergic polymorphisms (DRD1: rs265981, DRD2/ANKK1: rs1800497, DRD3: rs6280, DRD4: VNTR 48 bp, DRD5: VNTR 130-166 bp, DBH: rs2519152, DAT1: VNTR 40 bp, COMT: rs4680, MAOA: VNTR 30 bp), a polygenic score (PGS) based on nine alleles leading to lower dopamine responsiveness, and a PGS based on three alleles associated with both higher reward sensitivity and better executive functioning (DRD2/ANKK1: "G" allele, COMT: Met allele, DAT1: 440-bp allele).

RESULTS

No association with total exercise volume or externally paced exercise volume was found for individual alleles or the nine-allele PGS. The volume of externally paced exercise behavior was significantly associated with the reward and executive function congruent PGS. This association was driven by the DAT1 440-bp and COMT Met allele, which acted as increaser alleles for externally paced exercise behavior.

CONCLUSIONS

Taking into account the types of exercise activity may increase the success of identifying genetic variants and unraveling the neurobiology of voluntary exercise behavior.

The Interplay between Genes and Psychosocial Home Environment on Physical Activity

INTRODUCTION

Genetic factors contribute to individual differences in physical activity, but it remains uncertain whether the magnitude of the genetic effects is modified by variations in home environments. We aimed to examine to what extent the psychosocial home environment in childhood and adolescence modifies the genetic influences on leisure time physical activity in young adulthood.

METHODS

Participants were Finnish twins (N = 3305) who reported their leisure time physical activity at age 24 yr. The psychosocial home environment was assessed by twins at ages 12, 14, and 17 yr, as well as by their parents when the twins were age 12 yr. Gene-environment interaction modeling was performed with OpenMx software.

RESULTS

Parental ratings of positive home atmosphere as well as the twins' ratings of both positive home atmosphere at age 14 yr and lower relational tensions at ages 12 and 14 yr predicted higher leisure time physical activity levels in young adulthood (regression coefficients = 0.33-0.64). Parental perceptions as well as the twins' perceptions of positive home atmosphere at ages 14 and 17 yr increased the additive genetic variation (moderation effects: 0.55, 95% confidence interval [CI] = 0.29-0.80; 0.60, 95% CI = 0.26-1.05; and 0.52, 95% CI = 0.19-0.87, respectively). The twins' ratings of positive home atmosphere at age 12 yr and lower relational tensions at ages 12 and 14 yr increased the unique environmental variation of their subsequent physical activity (moderation effects: 0.46, 95% CI = 0.19-0.60; 0.48, 95% CI = 0.29-0.64; and 0.85, 95% CI = 0.12-0.95, respectively).

CONCLUSIONS

A psychosocial home environment that is warm and supportive in childhood and adolescence not only increases the mean level of subsequent leisure time physical activity in young adulthood but also modifies the genetic and environmental variances in leisure time physical activity.

Demographic, physical and mental health assessments in the adolescent brain and cognitive development study: Rationale and description

The Adolescent Brain and Cognitive Development (ABCD) Study incorporates a comprehensive range of measures assessing predictors and outcomes related to both mental and physical health across childhood and adolescence. The workgroup developed a battery that would assess a comprehensive range of domains that address study aims while minimizing participant and family burden. We review the major considerations that went into deciding what constructs to cover in the demographics, physical health and mental health domains, as well as the process of selecting measures, piloting and refining the originally proposed battery. We present a description of the baseline battery, as well as the six-month interim assessments and the one-year follow-up assessments. This battery includes assessments from the perspectives of both the parent and the target youth, as well as teacher reports. This battery will provide a foundational baseline assessment of the youth's current function so as to permit characterization of stability and change in key domains over time. The findings from this battery will also be utilized to identify both resilience markers that predict healthy development and risk factors for later adverse outcomes in physical health, mental health, and substance use and abuse.

Heritability of heart rate recovery and vagal rebound after exercise

Purpose

The prognostic power of heart rate recovery (HRR) after exercise has been well established but the exact origin of individual differences in HRR remains unclear. This study aims to estimate the heritability of HRR and vagal rebound after maximal exercise in adolescents. Furthermore, the role of voluntary regular exercise behavior (EB) in HRR and vagal rebound is tested.

Methods

491 healthy adolescent twins and their siblings were recruited for maximal exercise testing, followed by a standardized cooldown with measurement of the electrocardiogram and respiratory frequency. Immediate and long-term HRR (HRR60 and HRR180) and vagal rebound (heart rate variability in the respiratory frequency range) were assessed 1 and 3 min after exercise. Multivariate twin modeling was used to estimate heritability of all measured variables and to compute the genetic contribution to their covariance.

Results

Heritability of HRR60, HRR180 and immediate and long-term vagal rebound is 60 % (95 % CI: 48–67), 65 % (95 % CI: 54–73), 23 % (95 % CI: 11–35) and 3 % (95 % CI: 0–11), respectively. We find evidence for two separate genetic factors with one factor influencing overall cardiac vagal control, including resting heart rate and respiratory sinus arrhythmia, and a specific factor for cardiac vagal exercise recovery. EB was only modestly associated with resting heart rate (r = −0.27) and HRR (rHRR60 = 0.10; rHRR180 = 0.19) with very high genetic contribution to these associations (88–91 %).

Conclusions

Individual differences in HRR and immediate vagal rebound can to a large extent be explained by genetic factors. These innate cardiac vagal exercise recovery factors partly reflect the effects of heritable differences in EB.