The effects of physical activity and exercise training on psychological stress and well-being in an adolescent population

Molecular consequences of psychological stress in human aging

Psychological stress has often been described as a feeling of being overwhelmed by the necessity of constant adjustment to an individual's changing environment. Stress affects people of all ages, but the lives of the elderly may particularly be affected. Major changes can cause anxiety leading to feelings of insecurity and/or loss of self-esteem and depression. The cellular mechanisms underlying psychological stress are poorly understood. This review focuses on the physical and molecular consequences of psychological stress linked to aging processes and, in particular, how molecular changes induced by psychological stress can compromise healthy aging.

Canadian Society for Exercise Physiology position stand: Benefit and risk for promoting childhood physical activity

Current guidelines recommend children accumulate 60 min of daily physical activity; however, highly publicized sudden-death events among young athletes raise questions regarding activity safety. An expert group convened (June 2012) to consider the safety of promoting increased physical activity for children, and recommended the publication of an evidence-based statement of current knowledge regarding the benefits and risks of physical activity for children. Recommendations for encouraging physical activity while maximizing the opportunity to identify children who have been prescribed a physical activity restriction include (1) professionals and (or) researchers that encourage children to change the type of physical activity or to increase the frequency, intensity, or duration of their activity should inquire whether a child has primary healthcare provider-prescribed activity limitations before the child’s activity participation changes; (2) physical activity researchers should prioritize the development of evidence regarding the benefits and risks of childhood physical activity and inactivity, particularly data on the risks of sedentary lifestyles and physical activity-associated injury risks that accounts for the amount of activity performed, and the effectiveness of current risk-management strategies and screening approaches; (3) professionals and researchers should prioritize the dissemination of information regarding the benefits of physical activity and the risks of sedentary behaviour in children; and (4) parents and professionals should encourage all children to accumulate at least 60 min of physical activity daily. The recommendations are established as a minimum acceptable standard that is applicable to all physical activity opportunities organized for children, whether those opportunities occur in a community, school, or research setting.

Biological mechanisms underlying the role of physical fitness in health and resilience

Physical fitness, achieved through regular exercise and/or spontaneous physical activity, confers resilience by inducing positive psychological and physiological benefits, blunting stress reactivity, protecting against potentially adverse behavioural and metabolic consequences of stressful events and preventing many chronic diseases. In this review, we discuss the biological mechanisms underlying the beneficial effects of physical fitness on mental and physical health. Physical fitness appears to buffer against stress-related disease owing to its blunting/optimizing effects on hormonal stress responsive systems, such as the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system. This blunting appears to contribute to reduced emotional, physiological and metabolic reactivity as well as increased positive mood and well-being. Another mechanism whereby regular exercise and/or physical fitness may confer resilience is through minimizing excessive inflammation. Chronic psychological stress, physical inactivity and abdominal adiposity have been associated with persistent, systemic, low-grade inflammation and exert adverse effects on mental and physical health. The anti-inflammatory effects of regular exercise/activity can promote behavioural and metabolic resilience, and protect against various chronic diseases associated with systemic inflammation. Moreover, exercise may benefit the brain by enhancing growth factor expression and neural plasticity, thereby contributing to improved mood and cognition. In summary, the mechanisms whereby physical fitness promotes increased resilience and well-being and positive psychological and physical health are diverse and complex.

Rural Environments and Community Health (REACH): a randomised controlled trial protocol for an online walking intervention in rural adults

Background

Rural Australian adults are continually shown to be insufficiently active with higher prevalence of lifestyle-related diseases associated with physical inactivity compared to urban adults. This may, partly, be attributable to the challenges associated with implementing community-based physical activity programs in rural communities. There is a need for broadly accessible physical activity programs specifically tailored to the unique attributes of rural communities. The aim of the Rural Environments And Community Health (REACH) study is to evaluate the effectiveness of an online-delivered physical activity intervention for increasing regular walking among adults living in rural areas of South Australia.

Methods/Design

This is a randomised controlled trial. The intervention is 12-weeks with a 12-month follow-up. Participants will be insufficiently active, aged 18 to 70 years and randomly assigned to either Control or Intervention group. Participants receive a pedometer, but only the Intervention group will receive access to the purpose built REACH website where they will report steps taken, affect and ratings of perceived exertion during daily walking. These variables will be used to establish individualised step goals for increasing walking. Control participants will receive a paper diary to record their variables and generic incremental step goals.

The primary outcome measures are time spent in sedentary, light and moderate-to-vigorous intensity physical activity, measured by accelerometry. Secondary outcomes include 1) health measures (anthropometric and physiological), 2) psychological well-being, 3) diet quality, and 4) correlates of physical activity (exercise self-efficacy and physical activity environments). Measures will be collected at baseline, post-intervention, 6-month and 12-month follow-up.

Discussion

This protocol describes the implementation of a trial testing the effectiveness of an online resource designed to assist rural Australians to become more physically active. The outcomes of this study will guide the efforts of health promotion professionals by providing evidence for a relatively inexpensive, widely accessible and effective method for increasing physical activity that can be utilized by anyone with access to the internet. Findings may indicate future directions for the implementation of physical activity and other health related interventions in rural communities.

Trial registration

Australian New Zealand Clinical Trials Registry: ACTR12614000927628 (registered 28 August 2014).

Exercise, character strengths, well-being, and learning climate in the prediction of performance over a 6-month period at a call center

Background: Performance monitoring might have an adverse influence on call center agents' well-being. We investigate how performance, over a 6-month period, is related to agents' perceptions of their learning climate, character strengths, well-being (subjective and psychological), and physical activity.

Method: Agents (N = 135) self-reported perception of the learning climate (Learning Climate Questionnaire), character strengths (Values In Action Inventory Short Version), well-being (Positive Affect, Negative Affect Schedule, Satisfaction With Life Scale, Psychological Well-Being Scales Short Version), and how often/intensively they engaged in physical activity. Performance, “time on the phone,” was monitored for 6 consecutive months by the same system handling the calls.

Results: Performance was positively related to having opportunities to develop, the character strengths clusters of Wisdom and Knowledge (e.g., curiosity for learning, perspective) and Temperance (e.g., having self-control, being prudent, humble, and modest), and exercise frequency. Performance was negatively related to the sense of autonomy and responsibility, contentedness, the character strengths clusters of Humanity and Love (e.g., helping others, cooperation) and Justice (e.g., affiliation, fairness, leadership), positive affect, life satisfaction and exercise Intensity.

Conclusion: Call centers may need to create opportunities to develop to increase agents' performance and focus on individual differences in the recruitment and selection of agents to prevent future shortcomings or worker dissatisfaction. Nevertheless, performance measurement in call centers may need to include other aspects that are more attuned with different character strengths. After all, allowing individuals to put their strengths at work should empower the individual and at the end the organization itself. Finally, physical activity enhancement programs might offer considerable positive work outcomes.

Accelerometer use during field-based physical activity research in children and adolescents with intellectual disabilities: a systematic review

Many methodological questions and issues surround the use of accelerometers as a measure of physical activity during field-based research. To ensure overall research quality and the accuracy of results, methodological decisions should be based on study research questions. This paper aims to systematically review accelerometer use during field-based research in children and adolescents with intellectual disabilities. Medline, Embase, Cochrane Library, Web of Knowledge, PsycINFO, PubMed, and a thesis database (up to May 2013) were searched to identify relevant articles. Articles which used accelerometry-based monitors, quantified activity levels, and included ambulatory children and adolescents (≤ 18 years) with intellectual disabilities were included. Based on best practice guidelines, a form was developed to extract data based on 17 research components of accelerometer use. The search identified 429 articles. Ten full-text articles met the criteria and were included in the review. Many shortcomings in accelerometer use were identified, with the percentage of review criteria met ranging from 12% to 47%. Various methods of accelerometer use were reported, with most use decisions not based on population-specific research. However, a lack of measurement research, e.g., calibration/validation, for children and adolescents with intellectual disabilities is limiting the ability of field-based researchers to make to the most appropriate accelerometer use decisions. The methods of accelerometer use employed can have significant effects on the quality and validity of results produced, which researchers should be more aware of. To allow informed use decisions, there should be a greater focus on measurement research related to children and adolescents with intellectual disabilities.

Surgical resilience: a review of resilience biomarkers and surgical recovery

BACKGROUND

Two distinct and large bodies of literature exist on resilience that are of potential interest for surgical outcomes. First is the literature on the impact of resilience on surgical recovery and wound-healing. Second is the literature on biomarkers for resilience, which largely focuses on neuropeptide Y (NPY), testosterone and dehydroepiandrosterone (DHEA). Despite this activity, there is a dearth of literature linking these two bodies of research by investigating biomarkers for surgical resilience and its impact on surgical recovery. This paper reviews both bodies of literature within the context of surgical recovery.

METHOD

Literature searches within Medline and Embase were conducted for studies and previous reviews of resilience biomarkers and for the impact of individual resilience on surgical recovery. Reference lists of the reviews were searched for additional papers. No systematic review is yet possible due to the novelty of the use of resilience biomarkers within a surgical context.

RESULTS

This is the first review to explore a potential link between resilience biomarkers and surgical recovery. There are a number of biomarkers that correlate with individual resilience levels and resilient individuals exhibit better recovery trajectories following surgery, suggesting a novel use of such biomarkers for the identification of "surgical resilience".

CONCLUSION

By identifying surgical resilience, there is potential for utilising these biomarkers as prognostic indicators of likely recovery trajectories from surgery, which in turn complement individualised peri-operative management.

Stress and paediatric obesity: what we know and where to go

Childhood obesity is a public health epidemic and is associated with substantial negative physical and psychosocial health consequences. Stress is thought to be one contributor to the development and maintenance of obesity in children and adolescents, yet the linkage between stress and paediatric obesity is a poorly understood phenomenon. This paper furthers the understanding of stress in the context of paediatric obesity by firstly presenting a focused review of what is known about links between chronic and acute stress and paediatric obesity risk and then synthesizing important areas from the literature. These critical areas of focus include the following: (1) physiological stress reactivity; (2) stress-induced eating; (3) stress and physical activity; (4) parent and family influences; and (5) stress in at-risk populations. This review is geared toward facilitating future research on the stress-obesity connection in youth.

Lower cumulative stress is associated with better health for physically active adults in the community

Both cumulative adversity, an individual's lifetime exposure to stressors, and insufficient exercise are associated with poor health outcomes. The purpose of this study was to ascertain whether exercise buffers the association of cumulative adverse life events (CALE) with health in a community-wide sample of healthy adults (ages 18-50 years; women: n = 219, 29.5 ± 9.2 years; men: n = 176, 29.4 ± 8.7 years, mean ± standard deviation). Participants underwent the Cumulative Adversity Interview, which divides life events into three subsets: major life events (MLE), recent life events (RLE) and traumatic experiences (TLE). These individuals also completed the Cornell Medical Index and a short assessment for moderate or greater intensity exercise behavior, modified from the Nurses' Health Study. Results indicated that higher CALE was associated with greater total health problems (r = 0.431, p < 0.001). Interactions between stress and exercise were not apparent for RLE and TLE. However, at low levels of MLE, greater exercise was related to fewer total, physical, cardiovascular and psychological health problems (p value <0.05). Conversely, at high levels of MLE, the benefits of exercise appear to be absent. Three-way interactions were observed between sex, exercise and stress. Increased levels of exercise were related to better physical health in men, at all levels of CALE. Only women who reported both low levels of CALE and high levels of exercise had more favorable physical health outcomes. A similar pattern of results emerged for RLE. Together, these data suggest that increased exercise is related to better health, but these effects may vary by cumulative stress exposure and sex.

The effects of stress on physical activity and exercise

BACKGROUND

Psychological stress and physical activity (PA) are believed to be reciprocally related; however, most research examining the relationship between these constructs is devoted to the study of exercise and/or PA as an instrument to mitigate distress.

OBJECTIVE

The aim of this paper was to review the literature investigating the influence of stress on indicators of PA and exercise.

METHODS

A systematic search of Web of Science, PubMed, and SPORTDiscus was employed to find all relevant studies focusing on human participants. Search terms included "stress", "exercise", and "physical activity". A rating scale (0-9) modified for this study was utilized to assess the quality of all studies with multiple time points.

RESULTS

The literature search found 168 studies that examined the influence of stress on PA. Studies varied widely in their theoretical orientation and included perceived stress, distress, life events, job strain, role strain, and work-family conflict but not lifetime cumulative adversity. To more clearly address the question, prospective studies (n = 55) were considered for further review, the majority of which indicated that psychological stress predicts less PA (behavioral inhibition) and/or exercise or more sedentary behavior (76.4 %). Both objective (i.e., life events) and subjective (i.e., distress) measures of stress related to reduced PA. Prospective studies investigating the effects of objective markers of stress nearly all agreed (six of seven studies) that stress has a negative effect on PA. This was true for research examining (a) PA at periods of objectively varying levels of stress (i.e., final examinations vs. a control time point) and (b) chronically stressed populations (e.g., caregivers, parents of children with a cancer diagnosis) that were less likely to be active than controls over time. Studies examining older adults (>50 years), cohorts with both men and women, and larger sample sizes (n > 100) were more likely to show an inverse association. 85.7 % of higher-quality prospective research (≥ 7 on a 9-point scale) showed the same trend. Interestingly, some prospective studies (18.2 %) report evidence that PA was positively impacted by stress (behavioral activation). This should not be surprising as some individuals utilize exercise to cope with stress. Several other factors may moderate stress and PA relationships, such as stages of change for exercise. Habitually active individuals exercise more in the face of stress, and those in beginning stages exercise less. Consequently, stress may have a differential impact on exercise adoption, maintenance, and relapse. Preliminary evidence suggests that combining stress management programming with exercise interventions may allay stress-related reductions in PA, though rigorous testing of these techniques has yet to be produced.

CONCLUSIONS

Overall, the majority of the literature finds that the experience of stress impairs efforts to be physically active. Future work should center on the development of a theory explaining the mechanisms underlying the multifarious influences of stress on PA behaviors.

Anxiety and depression levels in prepubertal obese children: a case-control study

INTRODUCTION

Childhood obesity has become a worldwide epidemic in Western and in developing countries and has been accompanied by many serious and severe comorbidities, such as diabetes, hypertension, sleep apnea syndrome, depression, dyslipidemia, impaired glucose homeostasis, steatohepatitis, and intracranial hypertension, as well as medical concerns unique to youth, such as accelerated pubertal and skeletal development and orthopedic disorders. To date, no specific studies about the psychological assessment in pediatric obesity are present. Therefore, the aim of this study was to evaluate the putative relationship between psychological troubles and obesity in a sample of school-aged children.

MATERIALS AND METHODS

The study population consists of 148 obese subjects (body mass index [BMI] >95th percentile) (69 males, mean age 8.9±1.23 years) consecutively referred from clinical pediatricians to the Child and Adolescent Neuropsychiatry department at the Second University of Naples. In all subjects, weight, height, and BMI z-score were evaluated. In order to assess the anxiety levels and the presence of depressive symptoms, the Children Depression Inventory (CDI) and the Italian Self-Administered Psychiatric Scales for Children and Adolescents (SAFA) were administered. The control group consisted of 273 healthy children (129 males and 144 females) (mean age 9.1±1.8 years), enrolled in schools within the Campania region of Italy.

RESULTS

No significant differences between the two study groups were found for age (8.9±1.23 years in the obese sample and 9.1±1.8 years in the control group) (P=0.228) or sex (ratio male/female: 69/79 in the obese group versus 129/144 in the control group) (P=0.983). Obviously, significant difference was found for the BMI z-score (2.46±0.31 in the obese group vs 0.73±0.51 in the control group) (P<0.001). The obese subjects showed significant higher level of depressive symptoms (CDI total score) (16.82±7.73 vs 8.2±2.9) (P<0.001) and anxiety (SAFA - Anxiety [SAFA-A]) scale score (58.71±11.84 vs 27.75±11.5) (P<0.001) compared with the control group. Moreover, the Pearson's correlation analysis showed a significantly positive relationship between the BMI z-score and both the CDI (r=0.677; P<0.001) and SAFA-A scores (r=0.591; P<0.001).

CONCLUSION

Our findings highlighted the importance of assessing the presence of internalizing problems, such as anxiety and depression, in the common management of childhood obesity.

An exercise prescription primer for people with depression

A substantial body of evidence supports the value of exercise in the treatment of people with depression. The guidelines for exercise prescription, however, are limited, and based on those developed for healthy populations. This article explores the evidence for exercise in the treatment of depression and the role mental health nurses may play in the delivery of this information. A model of exercise prescription is put forward based on the available evidence and taking into account the challenges faced by mental health nurses and people with depression.

New methods for assessing the fascinating nature of nature experiences

In recent years, numerous environmental psychology studies have demonstrated that contact with nature as opposed to urban settings can improve an individual’s mood, can lead to increased levels of vitality, and can offer an opportunity to recover from stress. According to Attention Restoration Theory (ART) the restorative potential of natural environments is situated in the fact that nature can replenish depleted attentional resources. This replenishment takes place, in part, because nature is deemed to be a source of fascination, with fascination being described as having an “attentional”, an “affective” and an “effort” dimension. However, the claim that fascination with nature involves these three dimensions is to a large extent based on intuition or derived from introspection-based measurement methods, such as self-reports. In three studies, we aimed to more objectively assess whether these three dimensions indeed applied to experiences related to natural environments, before any (attentional) depletion has taken place. The instruments that were used were: (a) the affect misattribution procedure (Study 1), (b) the dot probe paradigm (Study 2) and (c) a cognitively effortful task (Study 3). These instrument were respectively aimed at verifying the affective, attentional and effort dimension of fascination. Overall, the results provide objective evidence for the claims made within the ART framework, that natural as opposed to urban settings are affectively positive (cfr., affective dimension) and that people have an attentional bias to natural (rather than urban) environments (cfr., attentional dimension). The results regarding the effort dimension are less straightforward, and suggest that this dimension only becomes important in sufficiently difficult cognitive tasks.

Physical activity interventions and depression in children and adolescents : a systematic review and meta-analysis

CONTEXT

Evidence suggests chronic physical activity (PA) participation may be both protective against the onset of and beneficial for reducing depressive symptoms.

OBJECTIVE

The aim of this article is to assess the impact of PA interventions on depression in children and adolescents using meta-analysis.

DATA SOURCES

Published English language studies were located from manual and computerized searches of the following databases: PsycInfo, The Cochrane Database of Systematic Reviews and The Cochrane Central Register of Controlled Trials, Trials Register of Promoting Health Interventions (TRoPHI; EPPI Centre), Web of Science and MEDLINE.

STUDY SELECTION

Studies meeting inclusion criteria (1) reported on interventions to promote or increase PA; (2) included children aged 5-11 years and/or adolescents aged 12-19 years; (3) reported on results using a quantitative measure of depression; (4) included a non-physical control or comparison group; and (5) were published in peer-reviewed journals written in English, up to and including May 2011 (when the search was conducted).

DATA EXTRACTION

Studies were coded for methodological, participant and study characteristics. Comprehensive Meta-Analysis version-2 software was used to compute effect sizes, with subgroup analyses to identify moderating characteristics. Study quality was assessed using the Delphi technique.

RESULTS

Nine studies were included (n = 581); most were school-based randomized controlled trials, randomized by individual. Studies used a variety of measurement tools to assess depressive symptoms. The summary treatment effect was small but significant (Hedges' g = -0.26, standard error = 0.09, 95% confidence intervals = -0.43, -0.08, p = 0.004). Subgroup analyses showed that methodological (e.g. studies with both education and PA intervention; those with a higher quality score; and less than 3 months in duration) and participant characteristics (e.g. single-gender studies; those targeting overweight or obese groups) contributed most to the reduction in depression.

CONCLUSIONS

There was a small significant overall effect for PA on depression. More outcome-focused, high-quality trials are required to effectively inform the implementation of programmes to reduce depressive symptoms in children and adolescents.

Mood disorders in youth: exercise, light therapy, and pharmacologic complementary and integrative approaches

The therapeutic value of physical exercise, bright light therapy and dawn simulation, and several pharmacologic treatments, including hypericum (St. John's wort), S-adenosylmethionine, and 5-hydroxytryptophan, are reviewed, with a focus on their use for treating major depressive disorder in children and adolescents and also for alleviating depressed mood in the general (nonclinical) population of youth. For each treatment discussed, all published randomized, double-blind, placebo-controlled trials are summarized, along with some additional selected studies. Nutritional psychopharmacology and several other approaches to treating depression will be presented in an upcoming volume in the Child and Adolescent Psychiatric Clinics of North America.

Is cardiovascular or resistance exercise better to treat patients with depression? A narrative review

OBJECTIVES

There is growing evidence regarding the efficacy of exercise as a treatment strategy for patients with depression. This paper summarises the benefits of both cardiovascular and resistance exercise for patients with depression.

DESIGN

A narrative review design was employed. Supporting literature for the individual and combined benefits of both modalities are presented. Studies comparing both modalities are then discussed.

RESULTS

The outcomes of the review indicate that there is evidence for the efficacy of both cardiovascular exercise and resistance exercise, either independently or combined, in the treatment of depression across the range of severity levels and age groups.

CONCLUSION

Exercise interventions for the treatment of depression appear worthwhile and well tolerated. Exercise preference, access to resources and social support may shape the choice for the patient. The role of primary and allied health professionals in guiding this choice is discussed. Implications for clinical practice and further research are presented.

Momentary assessment of affect, physical feeling states, and physical activity in children

OBJECTIVE

Most research on the interplay of affective and physical feelings states with physical activity in children has been conducted under laboratory conditions and fails to capture intraindividual covariation. The current study used Ecological Momentary Assessment (EMA) to bidirectionally examine how affective and physical feeling states are related to objectively measured physical activity taking place in naturalistic settings during the course of children's everyday lives.

METHODS

Children (N = 119, ages 9-13 years, 52% male, 32% Hispanic) completed 8 days of EMA monitoring, which measured positive affect (PA), negative affect (NA), feeling tired, and feeling energetic up to 7 times per day. EMA responses were time-matched to accelerometer assessed moderate-to-vigorous physical activity (MVPA) in the 30 min before and after each EMA survey.

RESULTS

Higher ratings of feeling energetic and lower ratings of feeling tired were associated with more MVPA in the 30 min after the EMA prompt. More MVPA in the 30 min before the EMA prompt was associated with higher ratings of PA and feeling energetic and lower ratings of NA. Between-subjects analyses indicated that mean hourly leisure-time MVPA was associated with less intraindividual variability in PA and NA.

CONCLUSIONS

Physical feeling states predict subsequent physical activity levels, which in turn, predict subsequent affective states in children. Active children demonstrated higher positive and negative emotional stability. Although the strength of these associations were of modest magnitude and their clinical relevance is unclear, understanding the antecedents to and consequences of physical activity may have theoretical and practical implications for the maintenance and promotion of physical activity and psychological well-being in children.

Afterschool program participation, youth physical fitness, and overweight

BACKGROUND

Fighting childhood obesity has become a key policy focus. The role of community-based interventions to promote physical activity is an important part of an overall strategy to increase physical activity for youth.

PURPOSE

This study examines whether community-based afterschool physical activity programs lead to improved youth fitness and lower obesity rates.

METHODS

Individually linked, longitudinal administrative data were used from local afterschool programs and two school districts in one California community to follow 1105 students from the 2006-2007 to 2008-2009 school years. Models were estimated in 2009-2010 using linear probability regressions and robust SEs, controlling for individual, family, and school characteristics, including fitness and overweight status prior to program participation.

RESULTS

One third (36%) of the students participated in fitness-focused afterschool programs. Controlling for baseline fitness status, participating in fitness-focused afterschool programs was associated with a 10% increase in the probability of being physically fit after 2 years. This finding held for nearly all subgroups, including students who were initially unfit. Participation in 2 years of the program was associated with a 14.7% increased likelihood of subsequent fitness compared to 8.8% for 1 year of participation. Participation in other types of afterschool programs was not associated with fitness improvements. There were no effects of participation in either type of program on overweight status.

CONCLUSIONS

These findings point to the promise of relying on existing community resources in the fight against childhood obesity. Fitness-focused afterschool programs will need to ensure that the highest-risk children--including those who are Latino and low-income--are served.

The psychological benefits of recreational running: a field study

Running yields positive changes in affect, but the external validity of controlled studies has received little attention in the literature. In this inquiry, 50 recreational runners completed the Exercise-Induced Feeling Inventory (Gauvin & Rejeskí, 1993) before and after a bout of self-planned running on an urban running path. Positive changes were seen in all four measures of affect (p < .001). Multivariate regressions were performed to examine the contribution of four exercise characteristics (i.e., duration of the current run, weekly running time, weekly running distance, and running experience) to the observed changes in affect. The results have revealed that exercise characteristics accounted for only 14-30% of the variance in the recreational runners' affect, in both directions. It is concluded that psychological benefits of recreational running may be linked to placebo (conditioning and/or expectancy) effects.

Sportaktivität als Stresspuffer

Zusammenfassung: Die Rolle des Sports als Strategie der Stressregulation ist noch wenig systematisch erforscht. Im vorliegenden Beitrag wird die sog. „Stresspuffer-Hypothese der Sportaktivität“ genauer geprüft. Sie besagt, dass Sportaktivität die negativen Auswirkungen von Stress auf die Gesundheit „abzupuffern“ vermag. Bis heute ist diese Hypothese noch nicht überzeugend empirisch belegt, vor allem mangelt es an längsschnittlicher und experimenteller Evidenz. In der vorliegenden Studie wird die Stresspuffer-Hypothese sowohl quer- als auch längsschnittlich überprüft: N = 427 Angestellte machten an zwei Messzeitpunkten im Abstand von zehn Monaten Angaben zu ihrer seelischen Gesundheit, ihrem arbeitsbedingten Stresserleben und ihrer Sportaktivität. Die Ergebnisse bestätigen den Stresspuffereffekt auf der Ebene der Querschnittsanalysen – bei Betrachtung des aktuellen Stresserlebens und des aktuellen Sporttreibens – nur teilweise, auf der Ebene der Längsschnittanalysen – bei Betrachtung des chronischen Stresserlebens und des chronischen Sporttreibens – dagegen in vollem Umfang. Die Befunde deuten darauf hin, dass das habituelle Sportverhalten insbesondere bei zeitlich andauernden Stressbedingungen seine gesundheitsprotektive Wirkung zu entfalten vermag.

Longitudinal variation in adolescent physical activity patterns and the emergence of tobacco use

OBJECTIVE

The objective of this investigation was to examine how variation in adolescent physical activity is related to smoking and alternative tobacco use.

METHODS

Adolescents (N = 1,384) completed a self-report survey every 6 months from ages 14- to 18-years old in a prospective study of health behaviors. The 8 waves of data were analyzed using General Growth Mixture Modeling (GGMM) RESULTS: GGMM identified five physical activity trajectories including stable higher (SHPA), decreased (DPA), stable regular (SRPA), curvilinear (CPA), and stable low (SLPA). Across 4 years, the likelihood of smoking was greater among adolescents in the DPA, SLPA and SRPA trajectories compared to adolescents belonging to the SHPA trajectory. Alternative tobacco use was greatest among adolescents in the DPA and SRPA trajectories.

CONCLUSIONS

Adolescents with decreasing physical activity and even adolescents averaging an hour of physical activity a day (SRPA) are important groups to target for tobacco use prevention and intervention efforts.

Risk and Protective Factors for Depression in Youth

Risk and protective processes and mechanisms associated with depression in youth are discussed within a developmental–ecological framework. Risk factors at the individual (genetics, biology, affect, cognition, behaviour) and broader contextual levels (e.g., family, school, community) are proposed to interact, leading to the development of depression in youth. Transactions between these individual and contextual factors are suggested to be dynamic and reciprocal, and these transactions are expected to change over time and developmental course. The ‘best bet’ for the prevention of depression may be multicomponent and multilevel interventions that address the multiple risk and protective factors associated with depression. Preventive interventions need to focus on building protective factors within young people themselves, as well as creating health-promoting environments at home and at school. These interventions likely need to be long term and geared towards assisting youth across successive periods of development.

Regular exercise, subjective wellbeing, and internalizing problems in adolescence: causality or genetic pleiotropy?

This study tests in a genetically informative design whether exercise behavior causally influences subjective wellbeing (SWB) and internalizing problems (INT). If exercise causally influences SWB and INT, genetic and environmental factors influencing exercise behavior will also influence SWB and INT. Furthermore, within genetically identical (MZ) twin pairs, the twin who exercises more should also show higher levels of SWB and lower levels of INT, than the co-twin who exercises less, because genetic confounding is excluded. Data on these phenotypes were available in a sample of 6317 adolescent twins and 1180 non-twin-siblings. Most participants had longitudinal data with 2-year follow-up. Exercise behavior was cross-sectionally and longitudinally associated with fewer internalizing problems and increased SWB (correlations ranged from 0.12 to 0.16). Cross-sectional and longitudinal associations were mainly accounted for by genetic factors, whereas the contribution of environmental factors was negligible. Within MZ twin pairs, the twin who exercised more did not show fewer internalizing problems and increased SWB. This was found cross-sectionally and longitudinally. We conclude that exercise behavior is associated with fewer internalizing problems and higher levels of SWB. The association largely reflects the effects of common genetic factors on these traits.

Depressive symptoms and cardiorespiratory fitness in obese adolescents

PURPOSE

Depressive symptoms in adolescents have been associated with reduced physical activity. However, existing studies have relied on questionnaire measures of physical activity, which may not necessarily reflect actual energy expenditures. We sought to evaluate the relationship between depressive symptoms and objectively measured cardiorespiratory fitness among severely obese adolescents.

METHODS

One hundred thirty-four obese (body mass index [kg/m(2)]: ≥95th percentile) adolescent girls and boys (ages: 12-17 years) reported their depressive symptoms on the Children's Depression Inventory. Adolescents also participated in a maximal cycle ergometry exercise test to measure cardiorespiratory fitness. Body composition was assessed with dual-energy X-ray absorptiometry scanning.

RESULTS

Among the 103 adolescents who reached maximal exertion, those with elevated depressive symptoms (16%) displayed poorer cardiorespiratory fitness than those without elevated depressive symptoms (maximal oxygen uptake: 1,873.2 ± 63.6 vs. 2,012.9 ± 28.6 mL/min, p < .05). Symptoms of anhedonia also were related to lower fitness levels (p < .05). These effects were observed after accounting for age, sex, race, and lean mass.

CONCLUSIONS

Among obese adolescents, elevated depressive symptoms are associated with poorer objectively measured cardiorespiratory fitness. Future experimental tests should investigate whether cardiorespiratory fitness acts as a mediator of adolescent depressive symptoms' effect on obesity or obesity-related health comorbidities.

Physical activity and depression in adolescents: cross-sectional findings from the ALSPAC cohort

PURPOSE

Few studies have examined the association between physical activity (PA), measured objectively, and adolescent depressive symptoms. The aim of this study was to determine whether there is an association between objective measures of PA (total PA and time spent in moderate and vigorous PA (MVPA)) and adolescent depressive symptoms.

METHODS

Data on 2,951 adolescents participating in ALSPAC were used. Depressive symptoms were measured using the self-report Mood and Feelings Questionnaire (MFQ) (short version). Measures of PA were based on accelerometry. The association between PA and MFQ scores was modelled using ordinal regression.

RESULTS

Adolescents who were more physically active (total PA or minutes of MVPA) had a reduced odds of depressive symptoms [OR(adj) total PA (tertiles): medium 0.82 (95% CI: 0.69, 0.97); high 0.69 (95% CI: 0.57, 0.83)]; OR(adj) per 15 min MVPA: 0.92 (95% CI: 0.86, 0.98). In a multivariable model including both total PA and the percentage of time spent in MVPA, total PA was associated with depressive symptoms (OR(adj) total PA (tertiles): medium 0.82 (95% CI: 0.70, 0.98); high 0.70 (95% CI: 0.58, 0.85) but the percentage of time spent in MVPA was not independently associated with depressive symptoms [OR(adj) MVPA (tertiles) medium 1.05 (95% CI: 0.88, 1.24), high 0.91 (95% CI: 0.77, 1.09)].

CONCLUSIONS

The total amount of PA undertaken was associated with adolescent depressive symptoms, but the amount of time spent in MVPA, once total PA was accounted for, was not. If confirmed in longitudinal studies and randomised controlled trials, this would have important implications for public health messages.

Generalized anxiety disorder and anorexia nervosa: evidence of shared genetic variation

BACKGROUND

Previous studies have indicated a high prevalence of generalized anxiety disorder (GAD) in women with anorexia nervosa (AN). However, the shared genetic and environmental components of these disorders have not been explored. This study seeks to elucidate the shared genetic and environmental components between GAD and AN.

METHOD

Using 2,083 women from the Virginia Adult Twin Study of Psychiatric and Substance Use Disorders, structural equation modeling was used to obtain maximum likelihood estimates of the environmental genetic, shared and unique environmental components in 496 women with GAD, 47 women with AN, 43 women with GAD + AN, and 1,497 women without GAD or AN.

RESULTS

Results show that the heritability of GAD was 0.32 and AN was 0.31, and the genetic correlation between the two disorders was 0.20, indicating a modest genetic contribution to their comorbidity. Unique environment estimate was 0.68 for GAD and 0.69 for AN, with a unique environmental correlation of 0.18. All common environmental parameters were estimated at zero.

CONCLUSIONS

The modest shared genetic and unique environmental liability to both disorders may help explain the high prevalence of GAD in women with AN. This knowledge could help in the treatment and prevention of comorbid disorders.

Anorexia nervosa and generalized anxiety disorder: further explorations of the relation between anxiety and body mass index

We explore comorbidity of anorexia nervosa (AN) and generalized anxiety disorder (GAD) and their relation with body mass index (BMI) and evaluate the presence of fasting and excessive exercise which both have anxiolytic and weight loss effects. All participants were female: 32 with AN only, 607 with GAD only, 22 with AN and GAD (AN+GAD), and 5424 with no history of AN or GAD (referent) from the Swedish Twin study of Adults: Genes and Environment (STAGE). Lowest adult BMI differed significantly (p<.001) and was lower in those with AN+GAD than those with AN only (p<.029). Those with AN+GAD were most likely to endorse fasting and excessive exercise, followed by women with AN only, women with GAD only, and the referent. Comorbid AN and GAD may be a particularly pernicious presentation influencing both BMI and proclivity to engage in behaviors such as fasting and exercise that serve both weight loss and anxiolytic goals.

Diet and physical activity in women recovered from anorexia nervosa: a pilot study

OBJECTIVE

After recovery, women with anorexia nervosa (AN) tend to maintain lower body mass indices (BMI) than women in the general population. Reasons for this are unknown as little is known about diet, food choices, physical activity levels (PAL), and reasons for exercise in women recovered from AN.

METHOD

Diet, reasons for food choice, PAL, and reasons for exercise were measured in an exploratory study of 15 women recovered from AN and 22 women with no eating disorder history.

RESULTS

In these hypotheses generating analyses, mean BMI in recovered women was numerically lower than control women [21.4 kg/m(2) (2.0) and 23.6 kg/m(2) (4.4); respectively (p < .06)]. Recovered women were more likely to base food choice on health benefits (p < .04) compared with control women.

DISCUSSION

Pathological behaviors that are pathognomonic of AN may resolve into healthy food and activity choices that help maintain BMIs lower in the healthy range in recovered individuals.

Role of physical and sedentary activities in the development of depressive symptoms in early adolescence

OBJECTIVE

To examine whether levels of physical activity or sedentary activity are risk factors for the development of depressive symptoms in early adolescence.

METHODS

A representative sample of 2,464 12- to 15-year-old adolescents living in the middle of Norway was assessed twice, during the years 1998 (T1) and 1999/2000 (T2). The attrition rate was 4.3%. We assessed depressive symptoms (using the Mood and Feelings Questionnaire, MFQ) and levels of physical and sedentary activities at baseline and follow-up. Various potentially confounding factors, including demographic factors, were assessed at baseline.

RESULTS

The MFQ scores at T1 were cross-sectionally associated with low levels of vigorous exercise. A possible buffering effect of vigorous exercise on the relationship between stressful life events and depression was demonstrated. In longitudinal analysis low levels of vigorous exercise and high levels of sedentary activities (boys only) predicted a high score (MFQ ≥ 25) at T2.

CONCLUSIONS

Low levels of vigorous exercise and high levels of sedentary activities (boys only) constituted independent risk factors for the development of a high level of depressive symptoms in a 1-year study of young adolescents. This knowledge should be considered by policy makers, preventative services, and health-care professionals.

Elite Sport is Not an Additional Source of Distress for Adolescents with High Stress Levels

This study examined whether participation in elite sport inter acts with stress in decreasing or increasing symptoms of depression and anxiety among adolescents, and further, whether the interplay between participation in high-performance sport and stress is related to the perceived quality of sleep. 434 adolescents (278 girls, 156 boys; age: M = 17.2 yr.) from 15 “Swiss Olympic Sport Classes” and 9 conventional classes answered a questionnaire and completed a 7-day sleep log. Analyses of covariance showed that heightened stress was related to more depressive symptoms and higher scores for trait-anxiety Moreover, those classified as having poor sleep by a median split cutoff reported higher levels of depressive symptoms. No significant (multivariate) main effects were found for high-performance sport athletes. Similarly, no significant two- or three-way inter action effects were found. These results caution against exaggerated expectations concerning sport participation as a stress buffer. Nevertheless, participation in high-performance sport was not found to be an additional source of distress for adolescents who reported high stress levels despite prior research that has pointed toward such a relationship.

Aerobic exercise training reduces cannabis craving and use in non-treatment seeking cannabis-dependent adults

BACKGROUND

Cannabis dependence is a significant public health problem. Because there are no approved medications for this condition, treatment must rely on behavioral approaches empirically complemented by such lifestyle change as exercise.

AIMS

To examine the effects of moderate aerobic exercise on cannabis craving and use in cannabis dependent adults under normal living conditions.

DESIGN

Participants attended 10 supervised 30-min treadmill exercise sessions standardized using heart rate (HR) monitoring (60-70% HR reserve) over 2 weeks. Exercise sessions were conducted by exercise physiologists under medical oversight.

PARTICIPANTS

Sedentary or minimally active non-treatment seeking cannabis-dependent adults (n = 12, age 25±3 years, 8 females) met criteria for primary cannabis dependence using the Substance Abuse module of the Structured Clinical Interview for DSM-IV (SCID).

MEASUREMENTS

Self-reported drug use was assessed for 1-week before, during, and 2-weeks after the study. Participants viewed visual cannabis cues before and after exercise in conjunction with assessment of subjective cannabis craving using the Marijuana Craving Questionnaire (MCQ-SF).

FINDINGS

Daily cannabis use within the run-in period was 5.9 joints per day (SD = 3.1, range 1.8-10.9). Average cannabis use levels within the exercise (2.8 joints, SD = 1.6, range 0.9-5.4) and follow-up (4.1 joints, SD = 2.5, range 1.1-9.5) periods were lower than during the run-in period (both P<.005). Average MCQ factor scores for the pre- and post-exercise craving assessments were reduced for compulsivity (P  = .006), emotionality (P  = .002), expectancy (P  = .002), and purposefulness (P  = .002).

CONCLUSIONS

The findings of this pilot study warrant larger, adequately powered controlled trials to test the efficacy of prescribed moderate aerobic exercise as a component of cannabis dependence treatment. The neurobiological mechanisms that account for these beneficial effects on cannabis use may lead to understanding of the physical and emotional underpinnings of cannabis dependence and recovery from this disorder.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00838448].

Physical activity buffers the effects of family conflict on depressed mood: a study on adolescent girls and boys

This paper investigates the relationship between physical activity and depressed mood, under conditions of family conflict. We analyze data from a representative sample of 7,232 Icelandic adolescents. Analysis of variance was carried out to test for main and interaction effects. The study shows that while family conflict increases the likelihood of depressed mood, among adolescents, physical activity decreases the likelihood of depressed mood. Furthermore, physical activity plays a more important role among those adolescents living in aversive circumstances, than other adolescents, as family conflict and physical activity interact in the effect on depressed mood for adolescents living in such circumstances. The findings highlight the role of physical activity in decreasing mental distress among adolescents, especially those living in aversive circumstances at home.

Relationship between perceived stress and dietary and activity patterns in older adults participating in the Boston Puerto Rican Health Study

Previous research supports a relationship between psychological stress and chronic disease in Puerto Rican adults living in the Boston, Massachusetts area. Stress may affect health by influencing dietary and physical activity patterns. Therefore, perceived stress and two hypothesized mediators of stress-related food intake, insulin and cortisol, were examined for possible associations with dietary and activity patterns in >1300 Puerto Ricans (aged 45-75 years; 70% women) living in the Boston, Massachusetts area. Data were analyzed using multiple linear regression and ANCOVA. Greater perceived stress was associated with lower fruit, vegetable, and protein intake, greater consumption of salty snacks, and lower participation in physical activity. Stress was associated with higher intake of sweets, particularly in those with type 2 diabetes. Cortisol and stress were positively associated in those without diabetes. Cortisol was associated with higher intake of saturated fat and, in those with diabetes, sweet foods. Independent of diabetes, perceived stress was associated with higher circulating insulin and BMI. Our findings support a link between stress, cortisol, and dietary and activity patterns in this population. For high-sugar foods, this relationship may be particularly important in those with type 2 diabetes. Longitudinal research to determine causal pathways for these identified associations is warranted.

Smoking and quality of life among female survivors of breast, colorectal and endometrial cancers in a prospective cohort study

PURPOSE

To examine the association of smoking and quality of life (QOL) among survivors of breast, colorectal, or endometrial cancers.

METHODS

The study included women who joined the Iowa Women's Health Study in 1986 and were subsequently diagnosed with breast, colorectal, or endometrial cancers through 2004 (n = 1920). Smoking status was reported at baseline and in 2004; QOL was assessed in 2004 using the Medical Outcomes Study Short Form-36. Multivariate-adjusted odds ratios were calculated to examine the associations of smoking status and poor QOL (score lower than one-half a standard deviation below the mean of the non-smokers).

RESULTS

Compared with non-smokers, persistent smokers had higher likelihood of reporting poor Physical Functioning (odds ratio [OR] = 2.40, 95% confidence interval [CI] = 1.32-4.37), Mental Health (OR = 1.92, CI = 1.09-3.40), and Role Emotional (OR = 2.01, CI = 1.10-3.66), whereas former smokers had higher likelihood of reporting poor Physical Functioning (OR = 1.65, CI = 1.10-2.45), Mental Health (OR = 1.62, CI = 1.11-2.37), and General Health (OR = 1.51, CI = 1.03-2.21). A statistically significant trend toward higher likelihood of poor QOL was observed across smoking groups in Vitality, Physical Functioning, Mental Health, and Role Emotional. Further adjustment for physical activity resulted in attenuation of the odds ratios and p-values for trend.

CONCLUSION

Among women with breast, colorectal, or endometrial cancers, smokers were more likely than former or non-smokers to have poor QOL. Physical activity explained, in part, the association between smoking status and QOL in our study.

Physical activity plays an important role in body weight regulation

Emerging literature highlights the need to incorporate physical activity into every strategy intended to prevent weight gain as well as to maintain weight loss over time. Furthermore, physical activity should be part of any plan to lose weight. The stimulus of exercise provides valuable metabolic adaptations that improve energy and macronutrient balance regulation. A tight coupling between energy intake and energy expenditure has been documented at high levels of physical exercise, suggesting that exercise may improve appetite control. The regular practice of physical activity has also been reported to reduce the risk of stress-induced weight gain. A more personalized approach is recommended when planning exercise programs in a clinical weight loss setting in order to limit the compensatory changes associated to exercise-induced weight loss. With modern environment promoting overeating and sedentary behavior, there is an urgent need for a concerted action including legislative measures to promote healthy active living in order to curb the current epidemic of chronic diseases.

Prospective reciprocal relations between physical activity and depression in female adolescents

OBJECTIVE

Although an inverse correlation between physical activity and depression among adolescents has been found in research, this relation has seldom been examined prospectively. Thus, we tested whether physical activity reduces risk for future escalations in depression and whether depression decreases likelihood of future change in physical activity.

METHOD

Data from a longitudinal study involving annual assessments of 496 adolescent girls (mean age = 13 years, SD = 0.73) followed over a 6-year period were analyzed to address these questions.

RESULTS

Using analyses that controlled for several covariates, we found that physical activity significantly reduced risk for future increases in depressive symptoms and risk for onset of major-minor depression. Further, depressive symptoms and major-minor depression significantly reduced future physical activity. However, predictive effects were modest for both.

CONCLUSIONS

Results support a bidirectional relation between exercise and depression and imply that interventions that increase physical activity may reduce risk for depression among this high-risk population.

BDNF genotype moderates the relation between physical activity and depressive symptoms

OBJECTIVE

To test whether the BDNF gene interacts with exercise to predict depressive symptoms. Physical activity is associated with a range of positive health outcomes, including fewer depressive symptoms. One plausible mechanism underlying these findings involves Brain-Derived Neurotrophic Factor (BDNF), a protein hypothesized to limit or repair the damage caused by stress. Physical activity increases expression of BDNF, which may enhance brain health. BDNF expression is controlled by the BDNF gene. Compared with individuals without a BDNF met allele, met-allele carriers have a lower expression of BDNF, which has been associated with Major Depressive Disorder.

DESIGN

Eighty-two healthy adolescent girls were genotyped for the BDNF val66met polymorphism, and their depressive symptoms and physical activity were assessed using questionnaires.

MAIN OUTCOME MEASURES

BDNF genotype, Children's Depression Inventory, and the Physical Activity Questionnaire for Older Children and Adolescents.

RESULTS

The BDNF polymorphism was found to moderate the relation between exercise and depressive symptoms: being physically active was protective for girls with a BDNF met allele (fewer depressive symptoms) but not for girls with the val/val polymorphism.

CONCLUSION

By integrating psychological and biological factors, the present study enhances our understanding of how physical activity contributes to resilience to psychopathology.

Systematic review of the health benefits of physical activity and fitness in school-aged children and youth

Background

The purpose was to: 1) perform a systematic review of studies examining the relation between physical activity, fitness, and health in school-aged children and youth, and 2) make recommendations based on the findings.

Methods

The systematic review was limited to 7 health indicators: high blood cholesterol, high blood pressure, the metabolic syndrome, obesity, low bone density, depression, and injuries. Literature searches were conducted using predefined keywords in 6 key databases. A total of 11,088 potential papers were identified. The abstracts and full-text articles of potentially relevant papers were screened to determine eligibility. Data was abstracted for 113 outcomes from the 86 eligible papers. The evidence was graded for each health outcome using established criteria based on the quantity and quality of studies and strength of effect. The volume, intensity, and type of physical activity were considered.

Results

Physical activity was associated with numerous health benefits. The dose-response relations observed in observational studies indicate that the more physical activity, the greater the health benefit. Results from experimental studies indicate that even modest amounts of physical activity can have health benefits in high-risk youngsters (e.g., obese). To achieve substantive health benefits, the physical activity should be of at least a moderate intensity. Vigorous intensity activities may provide even greater benefit. Aerobic-based activities had the greatest health benefit, other than for bone health, in which case high-impact weight bearing activities were required.

Conclusion

The following recommendations were made: 1) Children and youth 5-17 years of age should accumulate an average of at least 60 minutes per day and up to several hours of at least moderate intensity physical activity. Some of the health benefits can be achieved through an average of 30 minutes per day. [Level 2, Grade A]. 2) More vigorous intensity activities should be incorporated or added when possible, including activities that strengthen muscle and bone [Level 3, Grade B]. 3) Aerobic activities should make up the majority of the physical activity. Muscle and bone strengthening activities should be incorporated on at least 3 days of the week [Level 2, Grade A].