Uwe Pühse

A school-based physical activity program to improve health and fitness in children aged 6-13 years ("Kinder-Sportstudie KISS"): study design of a randomized controlled trial (ISRCTN15360785)

BackgroundChildhood obesity is the result of a long lasting imbalance between energy intake and energy expenditure. A major contributing factor is physical inactivity which is closely linked to bone health, cardiovascular disease risk, fitness and psychological factors. The school seems to provide an excellent setting to enhance levels of physical activity (PA). However, there is insufficient data from previous school-based intervention trials on how to enhance overall PA. It is also unknown whether an intervention aimed at increasing PA is effective in improving the childrens health. The purpose of this paper is to outline the design of a school-based randomized, controlled trial (RCT) aiming to increase overall PA and to improve fitness and health in 6- to 13-year-old children.Methods/Design15 schools were randomized to the intervention (n = 9) or the control (n = 6) group, stratified by geographic region (urban vs. rural) and by age (1st and 5th grade). Participation was given for all children in the intervention group since in this group the intervention was part of the normal school curriculum. The intervention during one academic year consisted of: 1. two additional physical education classes per week given by trained physical education teachers adding up to a total of five PA classes per week, 2. short PA breaks (2–5 min each) during academic lessons, 3. PA home work, and 4. adaptation of recreational areas around the school. All children underwent anthropometric measurements, blood pressure assessment, fitness testing, measurement of PA and they filled out questionnaires. At least 70% of all children agreed to blood sampling and measurements of body composition and bone mineral measurements by dual energy x-ray absorptiometry. The primary endpoints of the study after one year were an increase in total PA by accelerometry, an increase in aerobic fitness measured by the 20 m shuttle run, a decrease in percent body fat derived from skinfold measurements and an increase in quality of life as assessed by the child health questionnaire in the intervention group compared to the control group. Secondary outcomes were overall fitness, differences in body composition including body fat distribution, cardiovascular risk factors, psychosocial health, bone mineral content and density of femur, lumbar spine and total body and food intake.DiscussionOur preliminary data suggest that the children were representative of Swiss children with respect to sex, socio-demographic status, and body mass index. Short-term results can be expected by the beginning of 2007. We hypothesized that our intervention will lead to an increase in PA, fitness and overall health. Based on our data, we aim to provide important information regarding the influence of such an intervention on these outcome measures in school-aged children and to provide nationwide guidelines to improve PA in children.

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.

Exercising, sleep-EEG patterns, and psychological functioning are related among adolescents

Abstract Objectives. Lay and scientific opinion alike hold that physical activity is efficient as both remedy and preventative measure for poor sleep. There is evidence that strenuous exercising of adolescent elite athletes leads to favourable sleep patterns. However, research on this in non-elite athletes is limited. The aim of the present study was to compare sleep-EEG patterns of higher leisure time exercisers and controls. Methods. A total 38 adolescents (M = 18.59) took part in the study; 17 were high, and 21 were low exercisers. Mean weekly exercise duration was 8.5 h for high and 2 h for low exercisers. Sleep-EEG recordings were performed following a day without exercise. Participants also completed questionnaires regarding their psychological functioning. Results. Compared to low exercisers, high exercisers had more slow wave sleep, and less light and REM sleep, higher scores for positive coping and curiosity, and lower scores for depressive symptoms and somatosensory amplification. Multiple regression analyses showed that weekly exercise duration predicted shortened SOL, low number of awakenings, and increased slow wave sleep. Conclusion. Regular, though not necessarily vigorous, exercise is related to improvement in objective sleep patterns and better psychological functioning. Regular physical activity should be promoted and access to sports facilities should be facilitated.

Daily Morning Running for 3 Weeks Improved Sleep and Psychological Functioning in Healthy Adolescents Compared With Controls

PURPOSE To compare sleep electroencephalographic patterns and psychological functioning of healthy adolescents running regularly in the mornings with those of control subjects. Although several studies have shown that regular moderate-to-vigorous exercise is related to favorable sleep and psychological functioning in adolescents, research on the effectiveness of short interventions is more limited. METHODS Fifty-one adolescents (mean age = 18.30 years; 27 female [53%]) took part in the study; they were randomly assigned either to a running or to a control group. The running group went running every morning for 30 minutes at moderate intensity during weekdays for 3 consecutive weeks. Sleep electroencephalographic patterns and psychological functioning were assessed in both groups before and after the 3-week period. All participants also kept a sleep log for 3 weeks. RESULTS Objective sleep improved (slow-wave sleep increased; sleep onset latency decreased) in the running group compared with the control group. Subjective sleep quality, mood, and concentration during the day improved, whereas sleepiness during the day decreased. CONCLUSIONS Thirty minutes of running in the morning during weekdays for 3 consecutive weeks impacted positively on sleep and psychological functioning in healthy adolescents compared with control subjects. Running is inexpensive and easy to implement during school schedules, and as both objective and subjective improvements were observed within 3 weeks, regular physical exercise should be promoted.

Are Adolescents With High Mental Toughness Levels More Resilient Against Stress

Mental toughness has been explored predominantly within sport contexts. Nevertheless, it is difficult to conceive mental toughness as only applicable to athletes. This study examines whether mentally tough participants exhibit resilience against stress. This is a cross-sectional study based on two different samples: Sample 1 consisted of 284 high school students (99 males, 185 females, M = 18.3 years). Sample 2 consisted of 140 first through fifth semester undergraduate students (53 males, 87 females, M = 20.0 years). Participants provided information about their level of perceived stress (10-item Perceived Stress Scale), mental toughness (48-item Mental Toughness Questionnaire) and depressive symptoms (Beck Depression Inventory). Consistent across the two samples, mental toughness mitigated the relationship between high stress and depressive symptoms. The interaction between stress and mental toughness explained 2% of variance in the adolescent sample and 10% of variance among young adults. The promotion of protective factors that foster resilient adaptation is a relevant issue. Mental toughness may appeal to individuals that are typically difficult to be reached with health interventions. Because mental toughness is part of young peoples daily speech, it may serve as a less academic resource than other health psychology concepts.

Fitness and exercise as correlates of sleep complaints: is it all in our minds?

PURPOSE Restoring sleep is associated with psychological well-being. In contrast, poor sleep leads to impaired daily cognitive, emotional, and social functioning. Both commonplace and expert opinion hold that exercise has a favorable impact on preventing poor sleep and improving its quality. However, the scientific basis for this opinion remains limited, and results are mixed. The aim of the present study, therefore, was to explore the impact of perceived physical fitness, exercise, and a perceived lack of activity on sleep in early adulthood. Gender-related patterns were also examined. METHODS A total of 862 participants (639 females and 223 males; mean +/- SD = 24.67 +/- 5.91 yr) took part in the study. Respondents completed a series of self-report questionnaires assessing perceived physical fitness, exercise, perceived lack of physical activity, insomnia (Insomnia Severity Index), dysfunctional sleep-related thoughts (Fragebogen zur Erfassung allgemeiner Persönlichkeitsmerkmale Schlafgestörter), and quality of sleep (Pittsburgh Sleep Quality Index). RESULTS High perceived physical fitness, but not exercise, was associated with favorable scores for various sleep indicators. A perceived lack of physical activity was associated with poor sleep. Perceived physical fitness and exercise were moderately correlated. Compared with males, females reported more sleep difficulties and also more dysfunctional sleep-related thoughts. CONCLUSIONS For early adulthood, findings did not support commonplace or expert opinion that exercise behavior has a favorable influence on sleep. Rather, the findings lend support to the importance of cognitive processes in the onset and maintenance of sleep complaints.

Increased self-reported and objectively assessed physical activity predict sleep quality among adolescents

Both scientists and the general public assume that physical activity (PA) is an effective, non-pharmacological approach to improvement in sleep quality. However, objective and reliable data on this relationship are scarce, particularly for adolescents. Therefore, the aims of the present study were to test the relationship by assessing both PA and sleep subjectively and objectively. A total of 56 adolescent vocational school students (Mean age=17.98, SD=1.36; 28 males, 28 females) participated in the study. Sleep and PA were subjectively assessed via questionnaires. Accelerometers objectively assessed PA, while sleep-EEG devices objectively assessed sleep. The data supported our prediction that adolescents with high PA levels would have longer TST, fewer wakening at night (WASO), fewer symptoms of insomnia, and higher sleep quality. However, gender influenced this pattern of results in that significant findings were only found between high self-reported PA levels and shorter perceived sleep onset latency (SOL). Though self-reported PA levels were a better predictor of good sleep than objectively assessed PA levels, gender was associated with sleep complaints; females reported more sleep complaints. Results indicate that among a non-clinical sample of adolescents increased PA is favorably associated with restoring sleep. Therefore, PA seems beneficial not only for physical and mental health, but also for sleep restoration.

“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.

Increased objectively assessed vigorous-intensity exercise is associated with reduced stress, increased mental health and good objective and subjective sleep in young adults

The role of physical activity as a factor that protects against stress-related mental disorders is well documented. Nevertheless, there is still a dearth of research using objective measures of physical activity. The present study examines whether objectively assessed vigorous physical activity (VPA) is associated with mental health benefits beyond moderate physical activity (MPA). Particularly, this study examines whether young adults who accomplish the American College of Sports Medicines (ACSM) vigorous-intensity exercise recommendations differ from peers below these standards with regard to their level of perceived stress, depressive symptoms, perceived pain, and subjective and objective sleep. A total of 42 undergraduate students (22 women, 20 men; M=21.24years, SD=2.20) volunteered to take part in the study. Stress, pain, depressive symptoms, and subjective sleep were assessed via questionnaire, objective sleep via sleep-EEG assessment, and VPA via actigraphy. Meeting VPA recommendations had mental health benefits beyond MPA. VPA was associated with less stress, pain, subjective sleep complaints and depressive symptoms. Moreover, vigorous exercisers had more favorable objective sleep pattern. Especially, they had increased total sleep time, more stage 4 and REM sleep, more slow wave sleep and a lower percentage of light sleep. Vigorous exercisers also reported fewer mental health problems if exposed to high stress. This study provides evidence that meeting the VPA standards of the ACSM is associated with improved mental health and more successful coping among young people, even compared to those who are meeting or exceeding the requirements for MPA.

Acute effects of moderate aerobic exercise on specific aspects of executive function in different age and fitness groups: A meta‐analysis

Whereas a wealth of studies have investigated acute effects of moderate aerobic exercise on executive function, the roles of age, fitness, and the component of executive function in this relationship still remain unclear. Therefore, the present meta-analysis investigates exercise-induced benefits on specific aspects of executive function in different age and aerobic fitness subgroups. Based on data from 40 experimental studies, a small effect of aerobic exercise on time-dependent measures (g = .35) and accuracy (g = .22) in executive function tasks was confirmed. The results further suggest that preadolescent children (g = .54) and older adults (g = .67) compared to other age groups benefit more from aerobic exercise when reaction time is considered as dependent variable. In contrast to age, aerobic fitness and the executive function component had no influence on the obtained effect sizes. Consequently, high aerobic fitness is no prerequisite for temporary improvements of the executive control system, and low- as well as high-fit individuals seem to benefit from exercise in a similar way. However, a higher sensitivity of executive function to acute aerobic exercise was found in individuals undergoing developmental changes. Therefore, preadolescent children and older adults in particular might strategically use a single aerobic exercise session to prepare for a situation demanding high executive control.