THE INFLUENCE OF THIRD GENERATION ARTIFICIAL SOCCER TURF CHARACTERISTICS ON GROUND REACTION FORCES DURING RUNNING

The aim of this study was to determine the effect of different artificial soccer turf pitches on the ground reaction forces of running soccer players. For this purpose ground reaction forces were determined for twenty soccer players while they ran at three different speeds across a 25 meter long track covered with a third generation artificial soccer turf. Three different pitches, two FIFA 1star and one FIFA 2star, were examined. There was no difference between the two 1star systems in the peak vertical and horizontal ground reactions forces. Data on the 2star system was equivocal due to a too small sample size. It is concluded that surface characteristics influence the loading of the human muscle-skeletal system more subtly than initially anticipated. A more detailed biomechanical analysis of the events during impact is required to identify the critical loading parameters

Estimating VO_2peak in 18–90 Year-Old Adults:Development and Validation of the FitMáx©-Questionnaire

Purpose: Cardiorespiratory fitness (CRF) plays an essential role in health outcomes and quality of life. However, it is often not assessed nor estimated. Objective CRF assessment is costly, labour intensive and not widely available. Patient-reported outcome measures estimate CRF more cost-efficiently, but current questionnaires lack accuracy. The aim of this study is to develop a new self-reported questionnaire to estimate CRF.</p

Decline in physical activity during adolescence is not associated with changes in mental health

The majority of studies investigating associations between physical activity and mental health in adolescents have been cross-sectional in design. Potential associations between physical activity and mental health may be better examined longitudinally as physical activity levels tend to decrease in adolescence. Few studies have investigated these associations longitudinally in adolescents and none by measuring physical activity objectively. A total of 158 Dutch adolescents (mean age 13.6 years, 38.6 % boys, grades 7 and 9 at baseline) participated in this longitudinal study. Physical activity, depressive symptoms and self-esteem were measured at baseline and at the 1-year follow-up. Physical activity was objectively measured with an ActivPAL3™ accelerometer during one full week. Depressive symptoms were measured with the Center for Epidemiologic Studies Depression Scale (CES-D) and self-esteem was assessed with the Rosenberg Self-Esteem Scale (RSE). Results were analysed using structural equation modelling

Physical activity and school absenteeism due to illness in adolescents

BACKGROUND: Knowledge about the beneficial role of physical activity (PA) for health and school performance is growing. Studies investigating the link between PA and school absenteeism due to illness are lacking. Therefore, we investigated associations between habitual PA and school absenteeism due to illness in adolescents and explored whether mental health and cardiovascular fitness mediated this association. METHODS: We studied 328 students in grades 7 and 9 (mean age 13.8 years; 49% boys). The PA was measured objectively by an ActivPAL3™ accelerometer attached on the thigh during 1 full week (24 hours/day). Depressive symptoms and self-esteem were self-reported by the Center for Epidemiologic Studies Depression Scale (CES-D) and Rosenberg Self-Esteem Scale, respectively, and included as a proxy for mental health in the analyses. Cardiovascular fitness was measured by the 20-m shuttle-run test. School absenteeism due to illness data was provided by the school administration. RESULTS: The PA was not significantly associated with school absenteeism, though there was an indirect association between PA and school absenteeism by cardiovascular fitness. CONCLUSIONS: Cardiovascular fitness mediates the association between PA and school absenteeism due to illness. Thus, cardiovascular fitness of students should be improved to reduce school absenteeism due to illness

The Effect of Standing Versus Sitting on Creativity in Adolescents—A Crossover Randomized Trial:The PHIT2LEARN Study

Creativity is important for school performance. As several brain mechanisms involved in creativity are stimulated by low-intensity physical activity, standing might influence creativity. Few studies on the relationship between standing and creativity have been executed, and none among vocational education and training (VET) students. Therefore, the aim of this study was to investigate whether standing influences creativity in VET students. In a randomized crossover study, 192 VET students were randomly allocated to standing or sitting (i.e., control) for 30 min. After 15 min, they performed two creativity tests: Guilford's Alternative Uses Test (divergent thinking) and Remote Associates Test (convergent thinking). Subsequently, conditions were switched, and the procedure was repeated. Multilevel analyses showed no significant effect of standing on divergent or convergent thinking test performance. Our results show that 30 min of standing does not affect creativity in VET students.</p