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

Childhood anxiety associated with low BMI in women with anorexia nervosa

OBJECTIVE

Extremely low body mass index (BMI) values are associated with increased risk for death and poor long-term prognosis in individuals with anorexia nervosa (AN). The present study explores childhood personality characteristics that could be associated with the ability to attain an extremely low BMI.

METHODS

Participants were 326 women from the Genetics of Anorexia Nervosa (GAN) Study who completed the Structured Interview for Anorexia Nervosa and Bulimic Syndromes and whose mother completed the Child Behavioral Checklist and/or Revised Dimensions of Temperament Survey.

RESULTS

Children who were described as having greater fear or anxiety by their mothers attained lower BMIs during AN (p < 0.02). Path analysis in the GAN and a validation sample, Price Foundation Anorexia Nervosa Trios Study, confirmed the relation between early childhood anxiety, caloric restriction, qualitative food item restriction, excessive exercise, and low BMI. Path analysis also confirmed a relation between childhood anxiety and caloric restriction, which mediated the relation between childhood anxiety and low BMI in the GAN sample only.

CONCLUSION

Fearful or anxious behavior as a child was associated with the attainment of low BMI in AN and childhood anxiety was associated with caloric restriction. Measures of anxiety and factors associated with anxiety-proneness in childhood may index children at risk for restrictive behaviors and extremely low BMIs in AN.

Review article: do exercise and fitness protect against stress-induced health complaints? A review of the literature

BACKGROUND

Understanding how exercise influences health is important in designing public health interventions. At present, evidence suggests that there is a positive relationship between exercise and health. However, whether this relationship is partly due to the stress-moderating impact of exercise has been less frequently investigated although more and more people are taxed by stressful life circumstances.

METHODS

A comprehensive review of studies testing the potential of exercise as a stress-buffer was conducted (including literature from 1982 to 2008). The findings are based on a narrative review method. Specific criteria were taken into account to evaluate causality of the evidence.

RESULTS

About half of the studies reported at least partly supportive results in the sense that people with high exercise levels exhibit less health problems when they encounter stress. The causality analyses show that stress-moderation effects were consistently found in different samples and with different methodological approaches. Although more support results from cross-sectional studies, exercise-based stress-buffer effects were also found in prospective, longitudinal and quasi-experimental investigations.

CONCLUSIONS

This review underscores the relevance of exercise as a public health resource. Recommendations are provided for future research. More prospective and experimental studies are needed to provide insight into how much exercise is necessary to trigger stress-buffer effects. Furthermore, more information is warranted to conclude which sort of exercise has the strongest impact on the stress-illness-relationship.

Adolescent smoking and depression: evidence for self-medication and peer smoking mediation

AIMS

The nature of the relationship between adolescent smoking and depression is unclear and the mechanisms that account for the comorbidity have received little investigation. The present study sought to clarify the temporal precedence for smoking and depression and to determine whether these variables are linked indirectly through peer smoking.

PARTICIPANTS

The sample was composed of 1093 adolescents participating in a longitudinal study of the behavioral predictors of smoking adoption.

DESIGN AND MEASUREMENTS

In this prospective cohort study, smoking, depression, peer smoking and other covariates were measured annually from mid-adolescence (9th grade; age 14) to late adolescence (12th grade, age 18).

FINDINGS

Parallel processes latent growth curve models supported a bidirectional relationship between adolescent smoking and depression, where higher depression symptoms in mid-adolescence (age 14) predicted adolescent smoking progression from mid- to late adolescence (ages 14-18). A significant indirect effect indicated that higher depression symptoms across time predicted an increase in the number of smoking peers, which in turn predicted smoking progression from mid-adolescence to late adolescence. In addition, smoking progression predicted a deceleration of depression symptoms from mid- to late adolescence. A significant indirect effect indicated that greater smoking at baseline predicted a deceleration in the number of smoking peers across time, which predicted a deceleration in depression symptoms from mid-adolescence to late adolescence.

CONCLUSIONS

The current study provides the first evidence of bidirectional self-medication processes in the relationship between adolescent smoking and depression and highlights peer smoking as one explanation for the comorbidity.

Chronic stress and obesity in adolescents: scientific evidence and methodological issues for epidemiological research

AIMS

This review describes the role of chronic stress in the development of obesity and available methodologies for the assessment of chronic stress in humans, in particular adolescents, with the aim of developing a feasible methodology to implement in an epidemiological study.

DATA SYNTHESIS

Chronic stress seems to be associated with the aetiology of obesity by interacting with both mechanisms of energy intake (increase of appetite and energy intake) and expenditure (decrease of physical activity) and by stimulating visceral fat accumulation in favour of abdominal obesity. However, more research is necessary to unravel the underlying mechanisms of the obesity-inducing effects of chronic stress, especially in adolescents. In addition to experimental research, epidemiological observational studies, in particular cohort studies, are appropriate given their non-intervening character, lower budgetary costs and natural setting. In practice, stress can be assessed by means of either a subjective approach using stressor checklists or interviews, or an objective approach measuring biomarkers of stress. In epidemiological research in adolescents, a combination of both strategies is recommended, with a preference for a general stressor checklist for adolescents and measurement of salivary cortisol, one of the most used and well-characterized biomarkers of stress.

CONCLUSION

This review provides basic evidence for the positive association between chronic stress and obesity, but also points out the need for more research in adolescents to further elucidate the role of chronic stress in the aetiology of obesity in this crucial life period. Good, well-standardized epidemiological surveys could be of great benefit in this research area.

Psychological stress and wound healing in humans: a systematic review and meta-analysis

OBJECTIVE

The current review aims to synthesize existing knowledge about the relationship between psychological stress and wound healing.

METHODS

A systematic search strategy was conducted using electronic databases to search for published articles up to the end of October 2007. The reference lists of retrieved articles were inspected for further studies and citation searches were conducted. In addition, a meta-analysis of a subset of studies was conducted to provide a quantitative estimation of the influence of stress on wound healing.

RESULTS

Twenty-two papers met the inclusion criteria of the systematic review and a subsample of 11 was included in a meta-analysis. The studies assessed the impact of stress on the healing of a variety of wound types in different contexts, including acute and chronic clinical wounds, experimentally created punch biopsy and blister wounds, and minor damage to the skin caused by tape stripping. Seventeen studies in the systematic review reported that stress was associated with impaired healing or dysregulation of a biomarker related to wound healing. The relationship between stress and wound healing estimated by the meta-analysis was r=-0.42 (95% CI=-0.51 to -0.32) (P<.01).

CONCLUSION

Attention now needs to be directed towards investigating potential moderators of the relationship, mediating mechanisms underpinning the association, as well as the demonstration of a causal link by the development of experimental interventions in healthy populations.

Physical activity, job demand-control, perceived stress-energy, and salivary cortisol in white-collar workers

PURPOSE

The aim of the present study is to examine the association between physical activity and perceived job demand, job control, perceived stress and energy, and physiological arousal reflected by morning and evening concentrations of cortisol in saliva among white-collar workers.

METHODS

Physical activity during the last week was assessed during work and leisure time by a Danish version of the International Physical Activity Questionnaire and saliva samples were collected. The study group comprised 389 white-collar workers, aged 25-67 years, and of which 257 were women.

RESULTS

We found that physical activity during leisure time was associated with higher perceived energy, and for men also with lower perceived stress. Further, we found that physical activity at leisure time affected the association between salivary cortisol and perceived stress and energy so that respondents being physically active at leisure time and perceiving higher energy showed higher evening saliva cortisol.

CONCLUSION

Physically active employees perceive less stress and more energy. The association between stress-energy and salivary cortisol was affected by vigorous physical activity. No association between job control-demand and the degree of physical activity was found. Based on the present data, we recommend office workers-exposed to high job strain and inactivity at the job-to perform physical activity, preferably of high intensity, in order to reduce stress and increase energy.

Weight change and appetite disturbance as symptoms of adolescent depression: toward an integrative biopsychosocial model

The Diagnostic and Statistical Manual of Mental Disorders [American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington, DC: Author.] lists weight change and appetite disturbance as a single compound symptom of depression at all ages. Nonetheless, assessment of these symptoms is complicated during adolescence by normative increases in body weight and appetitive drive as well as heightened rates of body dissatisfaction, dieting, and eating disorders. This review outlines biological and psychological mechanisms that may change the relation of weight change and appetite disturbance to depression during adolescence. We propose a developmental model of the relation of these symptoms to the disorder and use the model as a framework to summarize findings, limitations, and future directions of research. Although the literature suggests that weight change and appetite disturbance are related to adolescent depression, preliminary evidence suggests that interpretation of weight and appetite symptoms may depend on developmental level.

Aerobic exercise program reduces anger expression among overweight children

This study tested the effect of a structured aerobic exercise program on anger expression in healthy overweight children. Overweight sedentary children were randomly assigned to an aerobic exercise program or a no-exercise control condition. All children completed the Pediatric Anger Expression Scale at baseline and posttest. Anger Out and Anger Expression scores were lower for the exercise condition at posttest. Fitness improvements contributed significantly to final models, and points earned for adherence correlated negatively with posttest Anger Out. An aerobic exercise program might be an effective strategy to reduce anger expression, including reduction of aggressive behavior, in overweight children.

Aerobic exercise decreases the positive-reinforcing effects of cocaine

Aerobic exercise can serve as an alternative, non-drug reinforcer in laboratory animals and has been recommended as a potential intervention for substance abusing populations. Unfortunately, relatively little empirical data have been collected that specifically address the possible protective effects of voluntary, long-term exercise on measures of drug self-administration. The purpose of the present study was to examine the effects of chronic exercise on sensitivity to the positive-reinforcing effects of cocaine in the drug self-administration procedure. Female rats were obtained at weaning and immediately divided into two groups. Sedentary rats were housed individually in standard laboratory cages that permitted no exercise beyond normal cage ambulation; exercising rats were housed individually in modified cages equipped with a running wheel. After 6 weeks under these conditions, rats were surgically implanted with venous catheters and trained to self-administer cocaine on a fixed-ratio schedule of reinforcement. Once self-administration was acquired, cocaine was made available on a progressive ratio schedule and breakpoints were obtained for various doses of cocaine. Sedentary and exercising rats did not differ in the time to acquire cocaine self-administration or responding on the fixed-ratio schedule of reinforcement. However, on the progressive ratio schedule, breakpoints were significantly lower in exercising rats than sedentary rats when responding was maintained by both low (0.3mg/kg/infusion) and high (1.0mg/kg/infusion) doses of cocaine. In exercising rats, greater exercise output prior to catheter implantation was associated with lower breakpoints at the high dose of cocaine. These data indicate that chronic exercise decreases the positive-reinforcing effects of cocaine and support the possibility that exercise may be an effective intervention in drug abuse prevention and treatment programs.

Physical activity and emotional problems amongst adolescents : a longitudinal study

BACKGROUND

Promotion of physical activity (PA) is at the top of the public health agenda. However, there are few longitudinal studies investigating the relationship between PA and children's mental health. Therefore, we aimed to investigate the association between self-reported physical activity (PA) and emotional problems 1-year later in a cohort of schoolchildren.

METHODS

A total of 1,446 children aged 11-14 years from 39 schools in the North West of England completed a self-report questionnaire in class. Each child reported the total number of sessions of sporting activities (lasting more than 20 min) in which they participated during the previous week, including activities both in school and out of school. This total was averaged for the week in order to determine whether the child was physically active at recommended levels (1 h per day). Childhood emotional problems were measured using the Strengths and Difficulties Questionnaire (SDQ) (self-report) at baseline and 1-year later. Data on potential confounders were also collected by self-report questionnaire at baseline.

RESULTS

In unadjusted analyses, children who, on average, participated in at least 1 h of sporting activity on a daily basis had fewer emotional problems at 1-year follow-up. This attenuated substantially after adjustment for gender (girls were less active but more likely to report emotional problems than boys). After adjustment for additional confounders including emotional problems at baseline, children who met recommended levels for PA had, on average, a score on the emotional problems sub-scale that was 0.29 units lower (-0.29 (95%CI: -0.61, 0.022)) at 1 year follow-up compared to children who did not undertake recommended levels of PA. Children who were physical activity also had higher scores on the hyperactivity sub-scale of the SDQ 1 year later, but there was no evidence to support an association between PA and other behavioural problems.

CONCLUSIONS

Children who met recommended levels for PA had fewer emotional problems 1-year later, although the magnitude of this difference was reduced after adjustment for confounders, particularly gender. Future longitudinal studies need to record both PA and emotional problems at more frequent intervals in order to enable us to determine the effect of maintaining a physically active lifestyle on adolescent mental health outcomes.

"Don't crack under pressure!"--Do leisure time physical activity and self-esteem moderate the relationship between school-based stress and psychosomatic complaints?

OBJECTIVE

Stressful experiences occupy a central role in most etiological models of developmental psychopathology. Stress alone, however, insufficiently explains negative health outcomes. This raises the question why some children and adolescents are more vulnerable to the development of psychopathological symptoms than others. The primary purpose of this research was to demonstrate whether leisure time physical activity and self-esteem protect against stress-induced health problems.

METHOD

The findings are based on a cross-sectional study of 407 Swiss boys and girls (M=14.01 years). All variables are self-reported. Analyses of covariance were applied to test for main and moderator effects.

RESULTS

The findings suggest that school-based stress and psychosomatic complaints are important issues during adolescence. The results show that a higher level of psychosomatic complaints accompanies stress. Surprisingly, psychosomatic complaints and physical activity were unrelated. Likewise, no association was found between physical activity and stress. In contrast, students with high self-esteem reported significantly less complaints and a lower extent of perceived stress. Finally, the results do not support the stress-moderation hypothesis. Neither physical activity nor self-esteem buffered against the detrimental effects of school-based stress on psychosomatic health.

CONCLUSION

The findings lend support to previous research with German-speaking samples but are in marked contrast to Anglo-Saxon studies, which generally support the role of physical activity as a moderator of the health-illness relationship. In this investigation, developmental features and methodological limitations may have accounted for the insignificant results.

Factors related to smoking in college women

Cigarette smoking among American women attending college has increased dramatically since the 1980's. To develop effective smoking prevention and cessation programs, a better understanding of factors associated with smoking in college women is needed. Therefore, the purpose of this study was to examine if selected factors (stress, stress management, nutrition, physical activity, alcohol consumption, and race) were related to smoking in college women. A sample of 354 college women in a southeastern state, 18-22 years of age, participated in the study. Logistic regression analysis indicated that White race (p = < .001), alcohol consumption (p = .0013), and limited physical activity (p = .0078) were significantly associated with smoking. Physically active college women were 2 times less likely to be smokers. However, physical activity mediated the effect of stress and stress management on smoking. Additionally, stress management confounded the effect of stress on smoking. Therefore, in addition to alcohol avoidance, exercise (as a stress management strategy) may be an important component of primary prevention and smoking cessation programs for college women.

Physical activity behaviors and emotional self-efficacy: is there a relationship for adolescents?

BACKGROUND

This study explored relationships between physical activity (PA) behaviors and emotional self-efficacy (ESE) in a statewide sample of public high school adolescents in South Carolina (n=3836).

METHODS

The Center for Disease Control Youth Risk Behavior Survey PA items and an adolescent ESE scale were used. Logistic regression analyses and multivariate models constructed separately, revealed significant race by gender findings.

RESULTS

Results suggest that reduced vigorous PA (past 7 days), moderate PA (past 7 days), strengthening/toning exercises (past 7 days), and playing on sport teams (past 12 months) were associated (p<or=.05) with reduced ESE for specific race/gender groups.

CONCLUSIONS

Results have implications for school- and community-based mental health services and PA programs for adolescents. Measures of ESE as a component of comprehensive assessments of adolescent mental health and PA behaviors in fieldwork, research, and program-evaluation efforts should be considered.

The relationship between physical activity, sedentary behaviour and psychological wellbeing among adolescents

BACKGROUND

Previous studies examining the relationship between physical activity levels and broad-based measures of psychological wellbeing in adolescents have been limited by not controlling for potentially confounding variables. The present study examined the relationship between adolescents' self-reported physical activity level, sedentary behaviour and psychological wellbeing; while controlling for a broad range of sociodemographic, health and developmental factors.

METHODS

The study entailed a cross-sectional school-based survey in ten British towns. Two thousand six hundred and twenty three adolescents (aged 13-16 years) reported physical activity levels, patterns of sedentary behaviour (TV/computer/video usage) and completed the strengths and difficulties questionnaire (SDQ).

RESULTS

Lower levels of self-reported physical activity and higher levels of sedentary behaviour showed graded associations with higher SDQ total difficulties scores, both for boys (P < 0.001) and girls (P < 0.02) after adjustment for age and town. Additional adjustment for social class, number of parents, predicted school examination results, body mass index, ethnicity, alcohol intake and smoking status had little effect on these findings.

CONCLUSIONS

Low levels of self-reported physical activity are independently associated with diminished psychological wellbeing among adolescents. Longitudinal studies may provide further insights into the relationship between wellbeing and activity levels in this population. Ultimately, randomised controlled trials are needed to evaluate the effects of increasing physical activity on psychological wellbeing among adolescents.

Physical self-concept and self-esteem mediate cross-sectional relations of physical activity and sport participation with depression symptoms among adolescent girls

The authors tested whether physical self-concept and self-esteem would mediate cross-sectional relations of physical activity and sport participation with depression symptoms among 1,250 girls in 12th grade. There was a strong positive relation between global physical self-concept and self-esteem and a moderate inverse relation between self-esteem and depression symptoms. Physical activity and sport participation each had an indirect, positive relation with global physical self-concept that was independent of objective measures of cardiorespiratory fitness and body fatness. These correlational findings provide initial evidence suggesting that physical activity and sport participation might reduce depression risk among adolescent girls by unique, positive influences on physical self-concept that operate independently of fitness, body mass index, and perceptions of sports competence, body fat, and appearance.

Cardiorespiratory fitness and laboratory stress: a meta-regression analysis

We performed a meta-regression analysis of 73 studies that examined whether cardiorespiratory fitness mitigates cardiovascular responses during and after acute laboratory stress in humans. The cumulative evidence indicates that fitness is related to slightly greater reactivity, but better recovery. However, effects varied according to several study features and were smallest in the better controlled studies. Fitness did not mitigate integrated stress responses such as heart rate and blood pressure, which were the focus of most of the studies we reviewed. Nonetheless, potentially important areas, particularly hemodynamic and vascular responses, have been understudied. Women, racial/ethnic groups, and cardiovascular patients were underrepresented. Randomized controlled trials, including naturalistic studies of real-life responses, are needed to clarify whether a change in fitness alters putative stress mechanisms linked with cardiovascular health.

Relationship of vigorous physical activity to psychologic distress among adolescents

This article examines the relationship between vigorous physical activity and psychologic distress (by using the General Health Questionnaire-12) among a sample of 2,104 adolescents. Multiple regression analysis revealed a differential relationship between physical activity and dimensions of the General Health Questionnaire-12. Specifically, vigorous physical activity was related significantly to problems with social functioning but not to depression or anxiety.

Psychological interventions for depression in heart failure

BACKGROUND

Heart failure is a common and growing health problem. Depression is prevalent among these patients and is associated with an increased risk of mortality, in some, but not all, studies. Depression may increase the risk of recurrent cardiac events and death, either through direct pathophysiological mechanisms such as thrombogenesis or ventricular arrhythmias, or through behavioural mechanisms. Depressed patients are less likely to adhere to their medication regimen and modify their lifestyle appropriately, thereby increasing the likelihood of recurrent cardiac events and death. The effects of psychological interventions for depression in terms of reducing depression and improving prognosis in patients with heart failure are unknown.

OBJECTIVES

To assess the effects of psychological interventions for depression in people with heart failure on depression and quality of life, morbidity, and mortality in these patients.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials and The Database of Abstracts of Reviews of Effects on The Cochrane Library (Issue 3, 2003), MEDLINE (1951 to August 2003), PsycINFO (1887 to August 2003), CINAHL (1980 to August 2003) and EMBASE (1980 to August 2003). Searches of reference lists of retrieved papers were also made and expert advice was sought. Abstracts from national and international cardiology, psychology, and psychiatry conferences in 2003 and dissertation abstracts were also searched. All relevant foreign language papers were translated.

SELECTION CRITERIA

RCTs of psychological interventions for depression in adults (18 years or older) with heart failure. The primary outcome was a significant reduction in depression. The secondary outcomes were the acceptability of treatment, quality of life, cardiac morbidity (hospital re-admission for heart failure and non-fatal cardiovascular events), reduction of cardiovascular behavioural risk factors, health economics, and death.

DATA COLLECTION AND ANALYSIS

Two reviewers independently screened titles and abstracts of potential studies. Two reviewers independently assessed the full papers for inclusion criteria. Further information was sought from the authors where papers contained insufficient information to make a decision about eligibility.

MAIN RESULTS

No RCTs of psychological interventions for depression in patients with heart failure were identified.

AUTHORS' CONCLUSIONS

Depression is common among patients with heart failure. Randomised controlled trials of psychological interventions for depression in heart failure patients are needed to investigate the impact of such interventions on depression, quality of life, behavioural CVD risk factors, cardiac morbidity, health economics and mortality, given the paucity of such trials in this area and the increasing prevalence of heart failure.

Physical activity behaviors and perceived life satisfaction among public high school adolescents

This study explored relationships between perceived life satisfaction and physical activity behaviors in a statewide sample of adolescents in South Carolina (n = 4,758) using the CDC Youth Risk Behavior Survey (YRBS) and the Brief Multidimensional Student Life Satisfaction Scale (BMSLSS). Adjusted logistic regression analyses and multivariate models constructed separately revealed significant race by gender results. Not exercising for 20 minutes over the past 7 days (sweating and hard breathing), not performing stretching exercising (past 7 days), not exercising to strengthen or tone muscles (past 7 days), spending < 20 minutes actually exercising or playing sports in PE class, not playing on sport teams run by school, and not playing on sport teams run by outside school organizations were associated (p = .05) with reduced life satisfaction for specific race/gender groups. Results suggest implications for school and community-based physical activity programs. Future research should consider measures of life satisfaction as a component of comprehensive assessments of adolescent physical activity behaviors in fieldwork, research, and program evaluation.

Exercise to improve self-esteem in children and young people

BACKGROUND

Psychological and behavioural problems in children and adolescents are common, and improving self-esteem may help to prevent the development of such problems. There is strong evidence for the positive physical health outcomes of exercise, but the evidence of exercise on mental health is scarce.

OBJECTIVES

To determine if exercise alone or exercise as part of a comprehensive intervention can improve self-esteem among children and young people.

SEARCH STRATEGY

Computerised searches in MEDLINE, EMBASE, The Cochrane Controlled Trials Register (CENTRAL), CINAHL, PsycINFO and ERIC were undertaken and reference lists from relevant articles were scanned. Relevant studies were also traced by contacting authors. Dates of most recent searches: May 2003 in (CENTRAL), all others: January 2002.

SELECTION CRITERIA

Randomised controlled trials where the study population consisted of children and young people aged from 3 to 20 years, in which one intervention arm was gross motor activity for more than four weeks and the outcome measure was self-esteem.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected trials for inclusion, assessed the validity of included trials and extracted data. Investigators were contacted to collect missing data or for clarification when necessary.

MAIN RESULTS

Twenty-three trials with a total of 1821 children and young people were included. Generally, the trials were small, and only one was assessed to have a low risk of bias. Thirteen trials compared exercise alone with no intervention. Eight were included in the meta-analysis, and overall the results were heteregeneous. One study with a low risk of bias showed a standardised mean difference (SMD) of 1.33 (95% CI 0.43 to 2.23), while the SMD's for the three studies with a moderate risk of bias and the four studies with a high risk of bias was 0.21 (95% CI -0.17 to 0.59) and 0.57 (95% CI 0.11 to 1.04), respectively. Twelve trials compared exercise as part of a comprehensive programme with no intervention. Only four provided data sufficient to calculate overall effects, and the results indicate a moderate short-term difference in self-esteem in favour of the intervention [SMD 0.51 (95% CI 0.15 to 0.88)].

REVIEWER'S CONCLUSIONS

The results indicate that exercise has positive short-term effects on self-esteem in children and young people. Since there are no known negative effects of exercise and many positive effects on physical health, exercise may be an important measure in improving children's self-esteem. These conclusions are based on several small low-quality trials.

Influence of an interpersonal laboratory stressor on youths' choice to be physically active

OBJECTIVE

To determine whether interpersonal stress reduces youths' motivation to exercise in a laboratory setting.

RESEARCH METHODS AND PROCEDURES

Physical activity and sedentary behavior were measured in boys and girls across a control day, after reading children's magazines, and on a stress day, after giving a videotaped speech. For one analysis, children were divided into low (n = 12) and high (n = 13) heart-rate reactivity groups based on changes in heart rate to stress. In a second analysis, children were divided into low and high perceived level of stress based on changes in perceived stress. To determine differences in choice of exercise or sedentary behavior across the control and stress conditions, subjects chose either to exercise for progressively longer periods to earn a monetary reinforcer or to engage in a high-rated sedentary behavior.

RESULTS

The choice to exercise was influenced by stress reactivity differently in the stress and control conditions. Low heart-rate reactive children participated in similar (p > 0.50) amounts of exercise on the stress and control days, but high heart-rate reactive children participated in less (p < 0.01) exercise (22.0 +/- 2.5 vs. 26.3 +/- 2.2 minutes) on the stress than control days. When grouped by change in perceived stress, there were no group differences, but subjects exercised longer (p < 0.01) on the control day than the stress day.

DISCUSSION

Interpersonal stress decreased exercise in children susceptible to interpersonal stress. Stress-induced alterations in health behaviors may lead to weight gain in children.

Relieving the pressure? The role of physical activity in the relationship between school-related stress and adolescent health complaints

The present study includes a Norwegian sample of 15-year-old students (N = 1,670) and is part of a World Health Organization cross-national survey, Health Behavior in School-Aged Children (Currie, 1998). The objective was to examine the relationship between school-related stress, leisure time physical activity, and adolescent health complaints. Physical activity was also examined as a moderating variable in the relationship between school-related stress and health complaints. The results showed that high levels of complaints were associated in a linear relationship with high levels of school-related stress and low levels of leisure time physical activity. Reports of complaints were more closely related to stress for adolescents with low levels of physical activity; thus, physical activity seems to moderate the relationship between school-related stress and health complaints.

Differences in behavior, psychological factors, and environmental factors associated with participation in school sports and other activities in adolescence

This study examined whether participation in school team sports, exclusively or in combination with other extracurricular activities, is associated with higher levels of psychosocial functioning and healthy behavior than participation in other extracurricular activities alone or nonparticipation. The study sample includes 50,168 ninth grade public school students who completed an anonymous, voluntary statewide survey in 2001. Students were classified into four groups based on their participation in sports and other activities (such as clubs, volunteer work, band, choir, or music lessons): neither, both, other activities only, and sports only. Odds ratios for the group involved in both types of activities were significantly higher than those for all the other groups for all healthy behaviors and measures of connectedness, and significantly lower for all but one of the unhealthy behaviors. Students involved in sports, alone or in combination with other activities, had significantly higher odds than the other two groups for exercise, milk consumption, and healthy self-image, and significantly lower odds for emotional distress, suicidal behavior, family substance abuse, and physical and sexual abuse victimization. Students involved in other activities, alone or in combination with sports, had significantly higher odds than the other two groups for doing homework and significantly lower odds for alcohol consumption, marijuana use, and vandalism. The finding that abuse victims appeared to avoid sports but not other group activities raises concern and merits further research. Considering the potential benefits of participation in sports and other activities, more research is needed to identify and overcome barriers or deterrents, particularly for youth from low-income families.

Psychosocial correlates of physical activity and sedentary leisure habits in young adolescents: the Teens Eating for Energy and Nutrition at School study

BACKGROUND

Low levels of physical activity (PA) and highly sedentary leisure habits (SLH) in youth may establish behavioral patterns that will predispose youth to increased chronic disease risk in adulthood. The purpose of this paper was to examine associations of demographic and psychosocial factors with self-reported PA and SLH in young adolescents.

METHODS

A general linear mixed model predicted self-reported PA and SLH in the spring from demographic and psychosocial variables measured the previous fall in 3798 seventh grade students.

RESULTS

PA and SLH differed by race, with Caucasian students reporting among the highest PA and lowest SLH. Perceptions of higher academic rank or expectations predicted higher PA and lower SLH. Depressive symptomatology predicted higher SLH scores but not PA. Higher self-reported value of health, appearance, and achievement predicted higher PA and lower SLH in girls. Girls who reported that their mothers had an authoritative parenting style also reported higher PA and lower SLH.

CONCLUSIONS

Determinants of PA and SLH appear to differ from each other, particularly in boys. Development of effective programs to increase PA and/or decrease SLH in young adolescents should be based on a clear understanding of the determinants of these behaviors.

Absolute versus relative intensity of physical activity in a dose-response context

PURPOSE

To examine the importance of relative versus absolute intensities of physical activity in the context of population health.

METHODS

A standard computer-search of the literature was supplemented by review of extensive personal files.

RESULTS

Consensus reports (Category D Evidence) have commonly recommended moderate rather than hard physical activity in the context of population health. Much of the available literature provides Category C Evidence. It has often confounded issues of relative intensity with absolute intensity or total weekly dose of exercise. In terms of cardiovascular health, there is some evidence for a threshold intensity of effort, perhaps as high as 6 METs, in addition to a minimum volume of physical activity. Decreases in blood pressure and prevention of stroke seem best achieved by moderate rather than high relative intensities of physical activity. Many aspects of metabolic health depend on the total volume of activity; moderate relative intensities of effort are more effective in mobilizing body fat, but harder relative intensities may help to increase energy expenditures postexercise. Hard relative intensities seem needed to augment bone density, but this may reflect an associated increase in volume of activity. Hard relative intensities of exercise induce a transient immunosuppression. The optimal intensity of effort, relative or absolute, for protection against various types of cancer remains unresolved. Acute effects of exercise on mood state also require further study; long-term benefits seem associated with a moderate rather than a hard relative intensity of effort.

CONCLUSIONS

The importance of relative versus absolute intensity of effort depends on the desired health outcome, and many issues remain to be resolved. Progress will depend on more precise epidemiological methods of assessing energy expenditures and studies that equate total energy expenditures between differing relative intensities. There is a need to focus on gains in quality-adjusted life expectancy.

Factors associated with physical activity among Spanish youth through the National Health Survey

BACKGROUND

Physical inactivity is emerging as one of the largest public health problems throughout Europe. This study updates descriptive data on physical activity and the factors associated with it among the 6- to 15-year-old Spanish population during leisure time through the National Health Survey.

METHODS

This is a cross-sectional study from a representative sample of Spanish children's physical activity during their leisure time. Sample size was 1,358 children between the ages of 6 and 15 years. Univariate analyses were carried out first, and then significant variables were entered into a logistical regression nonconditional model.

RESULTS

Less than 30% of children were active and the percentage of active boys was higher than that of active girls in all age categories. From the age of 11 the percentage of total active children was stabilized. Children from the two highest social statuses (SS) were significantly more active than children from the lowest SS group. Children from large towns were more active than children from small towns. Active children reported eating more meat or fish than the less active ones.

CONCLUSIONS

The results suggest that characteristics of age, sex, town size, and social status should be considered when designing physical activity strategies for Spanish children.

Effects of physical exercise on anxiety, depression, and sensitivity to stress: a unifying theory

Until recently, claims for the psychological benefits of physical exercise have tended to precede supportive evidence. Acutely, emotional effects of exercise remain confusing, both positive and negative effects being reported. Results of cross-sectional and longitudinal studies are more consistent in indicating that aerobic exercise training has antidepressant and anxiolytic effects and protects against harmful consequences of stress. Details of each of these effects remain unclear. Antidepressant and anxiolytic effects have been demonstrated most clearly in subclinical disorder, and clinical applications remain to be exploited. Cross-sectional studies link exercise habits to protection from harmful effects of stress on physical and mental health, but causality is not clear. Nevertheless, the pattern of evidence suggests the theory that exercise training recruits a process which confers enduring resilience to stress. This view allows the effects of exercise to be understood in terms of existing psychobiological knowledge, and it can thereby provide the theoretical base that is needed to guide future research in this area. Clinically, exercise training continues to offer clinical psychologists a vehicle for nonspecific therapeutic social and psychological processes. It also offers a specific psychological treatment that may be particularly effective for patients for whom more conventional psychological interventions are less acceptable.

Psychosocial correlates of depressive symptoms among Japanese high school students

PURPOSE

To determine the psychosocial factors associated with the presence and persistence of depressive symptoms among high school students in Okinawa, Japan.

METHODS

The study sample was 3202 students from 12 public senior high schools. Students completed self-administered questionnaires from October through December 1997. We measured depressive symptomatology using the Center for Epidemiologic Studies Depression Scale. We asked students to report whether they had depressive symptoms at any time in the immediate past week, and whether those symptoms persisted for 5-7 days. The psychosocial variables examined were life stressors, perceived social support, health practices, self-esteem, and Locus of Control. The relationship between the psychosocial factors and depressive symptoms was examined using hierarchical multiple regression analyses.

RESULTS

After controlling for the effects of demographic and other psychosocial variables, presence of depressive symptoms was positively associated with life stressors in the domains of friends, family, and teachers. Similarly, persistence of depressive symptoms was also positively associated with life stressors in the domains of friends and teachers. Presence and persistence of depressive symptoms were negatively associated with positive health practices, more social support, high self-esteem, and internal Locus of Control.

CONCLUSIONS

The psychosocial variables associated with presence and persistence of depressive symptoms were remarkably consistent. Life stressors might be risk factors; on the contrary, positive health practices, perceived social support, high self-esteem, and internal Locus of Control might be protective factors of depressive symptoms among Japanese adolescents.

Therapeutic impact of exercise on psychiatric diseases: guidelines for exercise testing and prescription

Aerobic exercise seems to be effective in improving general mood and symptoms of depression and anxiety in healthy individuals and psychiatric patients. This effect is not limited to aerobic forms of exercise. There are almost no contraindications for psychiatric patients to participate in exercise programmes, provided they are free from cardiovascular and acute infectious diseases. However, very little is known about the effects of exercise in psychiatric disease other than those in depression and anxiety disorders. A few reports indicate the need for controlled investigations in psychotic and personality disorders. Unfortunately, no general concept for a therapeutic application of physical activity has been developed so far. Reliance on submaximal measures is highly recommended for fitness assessment. Monitoring of exercise intensity during training sessions is most easily done by measuring the heart rate using portable devices (whereas controlling the exact workload may be preferable for scientific purposes). Appropriate pre- and post-training testing is emphasised to enable adequate determinations of fitness gains and to eventually allow positive feedback to be given to patients in clinical settings.

A review of correlates of physical activity of children and adolescents

BACKGROUND

Understanding the factors that influence physical activity can aid the design of more effective interventions. Previous reviews of correlates of youth physical activity have produced conflicting results.

METHODS

A comprehensive review of correlates of physical activity was conducted, and semiquantitative results were summarized separately for children (ages 3-12) and adolescents (ages 13-18). The 108 studies evaluated 40 variables for children and 48 variables for adolescents.

RESULTS

About 60% of all reported associations with physical activity were statistically significant. Variables that were consistently associated with children's physical activity were sex (male), parental overweight status, physical activity preferences, intention to be active, perceived barriers (inverse), previous physical activity, healthy diet, program/facility access, and time spent outdoors. Variables that were consistently associated with adolescents' physical activity were sex (male), ethnicity (white), age (inverse), perceived activity competence, intentions, depression (inverse), previous physical activity, community sports, sensation seeking, sedentary after school and on weekends (inverse), parent support, support from others, sibling physical activity, direct help from parents, and opportunities to exercise.

CONCLUSION

These consistently related variables should be confirmed in prospective studies, and interventions to improve the modifiable variables should be developed and evaluated.

Leisure-time physical activity and psychosocial well-being in adolescents after cancer diagnosis

This preliminary study examined the relationship between leisure time physical activity (LTPA) and psychosocial well-being in 53 adolescents who were previously diagnosed with cancer. Participants completed a mailed, self-administered questionnaire in which they recalled their LTPA (including leisure time exercise and organized sport) at three time points (prediagnosis, treatment, and posttreatment). They also reported their current psychosocial well-being by using measures of depression and self-concept. Examination of the LTPA data revealed four main patterns across the cancer experience that were labeled maintainers (active at all three time points), temporary relapsers (active prediagnosis, inactive during treatment, active posttreatment), permanent relapsers (active prediagnosis, inactive during treatment, inactive posttreatment), and nonparticipants (inactive at all three time points). Multivariate analyses of variance indicated that self-concept differed significantly across the four organized sport patterns. Follow-up univariate analyses revealed significant differences for general self-concept, physical abilities, parental relations, same sex relations, and opposite sex relations with effect sizes ranging from medium-large to large. Post hoc tests generally showed that the maintainers exhibited superior scores on psychosocial well-being compared with the other three patterns. It was concluded that LTPA patterns across the cancer experience may be related to psychosocial well-being in adolescents after cancer diagnosis but that further research is warranted.

Exercise-induced regulation of brain-derived neurotrophic factor (BDNF) transcripts in the rat hippocampus

Previous results from our laboratory indicate that two nights of voluntary wheel running upregulates brain-derived neurotrophic factor (BDNF) mRNA expression in the hippocampus. In order to investigate the time-course of the BDNF response and to examine how physical activity preferentially activates particular transcriptional pathways, the effects of 6 and 12 h of voluntary wheel running on BDNF and exons I-IV mRNA expression were investigated in rats. Hippocampal full-length BDNF mRNA expression was rapidly influenced by physical activity, showing significant increases in expression levels as soon as 6 h of voluntary wheel running. Moreover, there was a strong positive correlation between distance run and BDNF mRNA expression. Exon I mRNA expression was significantly upregulated after 6 h of running and was maintained or enhanced by 12 h of voluntary running. Exon II had a slower time-course and was significantly upregulated after 12 h, selectively in the CA1 hippocampal region. Exon III and Exon IV showed no significant increase in expression level after 6 or 12 h of running in the paradigm studied. It is significant that the rapid neurotrophin response is demonstrated for a physiologically relevant stimulus, as opposed to the extreme conditions of seizure paradigms. Furthermore, exercise-induced upregulation of BDNF may help increase the brain's resistance to damage and neurodegeneration that occurs with aging.

Cognitive-behavioural interventions in cardiac rehabilitation

Evidence pertaining to the efficacy of cognitive-behavioural interventions, broadly defined, in cardiac rehabilitation is reviewed. Primary concerns lie with risk reduction and with the amelioration of psychological distress following myocardial infarction. The available data permit few definitive conclusions. The available data, on balance, suggest that programmes targeted at reducing Type A behaviours, smoking cessation, increasing exercise, or which teach stress management techniques, may be effective in reducing psychological distress and increasing effective coping, although frequently only in the short-term; it is more difficult to point to long-lasting advantage in this context. In addition, psychological interventions of this sort would seem to be associated with positive behavioural change. However, there is, as yet, little concerted evidence that such changes afford benefits in terms of coronary heart disease mortality or morbidity. Nevertheless, the pessimism of these conclusions may reflect shortcomings in study design and the failure to optimally match patients to programmes rather than an intrinsic lack of efficacy of the interventions.

Association among fitness components, anxiety, and confidence following aerobic training in aquarunning

The relationship of actual and perceived physiological and physical changes, i.e., VO2max, percent body fat, body weight, and perceived fitness change, to changes in anxiety and confidence were investigated. 15 adults volunteered to participate in an 8-wk. exercise program and 15 adults volunteered to be in a nonexercising control group. Physiological and physical measures (VO2max, percent body fat, body weight) were taken at Week 1 (pretest week) and Week 10 (posttest week) of the program. Each subject completed the Competitive Sport Anxiety Inventory-II prior to and just after the 8-wk. training program. Cognitive and somatic anxiety scores significantly decreased for both groups over the 8-wk. period. Confidence scores did not change for either group. The physiological variable and the physical measures were significantly related to cognitive anxiety, somatic anxiety, or confidence. It appears that both the aquarunning exercise and quiet rest sessions can be associated with anxiety within 8 wk.

Impact of a health promotion programme on multiple risk factors for CHD: a preliminary evaluation

Results are reported from a pilot study to evaluate an innovative health promotion programme (Lanark Health Club), in a community where the incidence of CHD is above average. The aim of the programme is to provide multiple risk factor screening and interventions--including an exercise programme--sited in the community and utilising existing resources within primary care and the voluntary sector. Data were returned by 54 respondents after six months' participation on the programme. Subjects' self-reported activity levels increased significantly over time, and there were concomitant significant reductions in weight, SBP and DBP. Reduced levels of self-reported stress were associated with reductions in alcohol intake, and were greater in male subjects. When other measures were controlled for, stress reduction was significantly more likely for those who also lost weight and exhibited a reduction in DBP. Finally, participation in the Health Club appeared to result in cholesterol reduction, particularly for those with relatively high initial cholesterol levels. While this could reflect regression effects, it is certainly worthy of more systematic examination.