@article{KahlertBrand2011,
  author    = {Kahlert, Daniela and Brand, Ralf},
  title     = {Questionnaires for assessing physical activity different response scale categories influence responses concerning health- and sport-related cognitions},
  series = {Zeitschrift f{\"u}r Gesundheitspsychologie},
  volume    = {19},
  journal   = {Zeitschrift f{\"u}r Gesundheitspsychologie},
  number    = {2},
  publisher = {Hogrefe},
  address   = {G{\"o}ttingen},
  issn      = {0943-8149},
  doi       = {10.1026/0943-8149/a000044},
  pages     = {96 -- 100},
  year      = {2011},
  abstract  = {The present study examines whether the use of different frequency scales in questionnaires about physical activity influences respondents' own estimation of their activity, as well as subsequent measurements of health- und sport-related cognitions and evaluations. Using a randomized research design we recruited a sample of 118 participants. One group received a high frequency scale for assessing their exercise frequency with the response categories "never", "less often", "once a month", "once a week", or "most days." The other group answered with a medium frequency scale with the alternatives "never", "less often", " once every few months", "once a month", and " once a week or more often." As dependent variables all participants judged the subjective importance of physical activity and their health-related quality of life (WHO-QOL-bref). Results indicate the expected response errors, owing to the fact that using a high-frequency scale produces higher levels of self-reported physical activity (Cramer's V = .30). Corresponding to this the subjective importance of physical activity increased (d = .37) and the health-related quality of life was judged to be better (d = .36). Such artefacts might be eliminated by using standardized formulations such as "I exercise... times per week/month for... minutes."},
  language  = {de}
}
@phdthesis{Hoehne2011,
  author    = {H{\"o}hne, Janet},
  title     = {Aktivit{\"a}ts- und Herzfrequenz-Monitoring zur Erfassung der Bewegungszeit und der Bewegungsintensit{\"a}t im schulischen und außerschulischen Kontext von Grundsch{\"u}lern im Land Brandenburg},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57937},
  school      = {Universit{\"a}t Potsdam},
  year      = {2011},
  abstract  = {"Kinderwelt ist Bewegungswelt" (Schmidt, 1997, S. 156, zitiert nach Schmidt, Hartmann-Tews \& Brettschneider, 2003, S. 31). Das kindliche Bewegungsverhalten hat sich bereits im Grundschulalter ver{\"a}ndert, so dass sich Bewegungsaktivit{\"a}ten von Kindern erheblich unterscheiden und keineswegs mehr verallgemeinert werden k{\"o}nnen. Richtet man den Fokus auf die Frage „Wie bewegt sind unsere Kinder?" so scheint diese von den Medien bereits beantwortet zu sein, da dort von ansteigendem Bewegungsmangel der heutigen Kinder gegen{\"u}ber fr{\"u}heren Generationen berichtet wird. Wenn es in den Diskussionen um den Gesundheitszustand unserer Kinder geht, nimmt die k{\"o}rperlich-sportliche Aktivit{\"a}t eine entscheidende Rolle ein. Bewegungsmangel ist hierbei ein zentraler Begriff der in der {\"O}ffentlichkeit diskutiert wird. Bei der Betrachtung der einzelnen Studien f{\"a}llt auf, dass deutliche Defizite in der Messung der k{\"o}rperlich-sportlichen Aktivit{\"a}t bestehen. Zentraler Kritikpunkt in den meisten Studien ist die subjektive Erfassung der k{\"o}rperlich-sportlichen Aktivit{\"a}t. Ein Großteil bisheriger Untersuchungen zum Bewegungsverhalten basiert auf Beobachtungen, Befragungen oder Bewegungstageb{\"u}chern. Diese liefern ausschließlich zum Teil subjektive Einsch{\"a}tzungen der Kinder oder Eltern {\"u}ber die tats{\"a}chliche Bewegungszeit und -intensit{\"a}t. Das objektive Erfassen der Aktivit{\"a}t bzw. Inaktivit{\"a}t ist zwar seit einigen Jahren zentraler Gegenstand vieler Studien, dennoch gilt es, dieses noch sachkundiger zu l{\"o}sen, um subjektive und objektive Daten zu vergleichen. Um dem Bewegungsmangel der heutigen Kinder entgegenzuwirken, sind empirisch abgesicherte Erkenntnisse {\"u}ber die Bedingungsfaktoren und die Folgen des ver{\"a}nderten Bewegungsverhaltens dringend n{\"o}tig. Die Quer- und L{\"a}ngsschnittuntersuchung umfasst die Bereiche Anthropometrie, die Erfassung der k{\"o}rperlich-sportlichen Aktivit{\"a}t und die Herzfrequenzmessung {\"u}ber 24h. F{\"u}r die Studie konnten 106 Jungen und M{\"a}dchen im Zeitraum von Januar 2007 bis April 2009 rekrutiert und {\"u}berpr{\"u}ft werden. Die physiologischen Parameter wurden mit Hilfe des ACTIHEART-Messsytems aufgezeichnet und berechnet. Die Ergebnisse zur k{\"o}rperlich-sportlichen Aktivit{\"a}t wurden in die Untersuchungsabschnitte Schulzeit gesamt, Pause, Sportunterricht, Nachmittag und 24h unterteilt. Durch das Messsystem werden die Bewegungsaktivit{\"a}t und die Herzfrequenz synchron aufgezeichnet. Das System nimmt die Beschleunigungswerte des K{\"o}rpers auf und speichert sie im frei w{\"a}hlbaren Zeitintervall, Short oder Long Term, in Form von „activity counts" ab. Das Messsytem berechnet weiterhin die Intensit{\"a}t k{\"o}rperlicher Aktivit{\"a}t.},
  language  = {de}
}
@article{JekaucWagnerKahlertetal.2013,
  author    = {Jekauc, Darko and Wagner, Matthias O. and Kahlert, Daniela and Woll, Alexander},
  title     = {Reliability and validity of MoMo-Physical-Activity-Questionnaire for Adolescents (MoMo-AFB)},
  series = {Diagnostica},
  volume    = {59},
  journal   = {Diagnostica},
  number    = {2},
  publisher = {Hogrefe},
  address   = {G{\"o}ttingen},
  issn      = {0012-1924},
  doi       = {10.1026/0012-1924/a000083},
  pages     = {100 -- 111},
  year      = {2013},
  abstract  = {This paper presents the psychometric properties of the MoMo-AFB (Bos, Worth, Opper, Oberger \& Woll, 2009), a questionnaire designed to measure the physical activity of children and adolescents. The MoMo-AFB consists of 28 items, covering the fields of everyday physical activity, sports within and outside of organised clubs, physical education as well as compliance with physical activity guidelines. A study was conducted with 109 boys and 87 girls aged between 9 and 17 years. The MoMo-AFB was given on two separate occasions to evaluate reliability and was compared with accelerometry data of ActiGraph GT1X to evaluate validity. The overall kappa/weighted kappa coefficient for the one-week testretest reliability was .66 (SD = .19) and the overall intraclass correlation (ICC) .68. Self-reported and accelerometer-measured average weekly time spent performing moderate to vigorous physical activity were significantly correlated (Spearman r = .29). Regarding reliability and validity, the MoMo-AFB is comparable with other international published physical activity questionnaires for adolescents.},
  language  = {de}
}
@phdthesis{Rietsch2013,
  author    = {Rietsch, Katrin},
  title     = {Body composition especially external skeletal robustness in association with physical activity and recreation in pre-pubertal children : a national and international investigation},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-66913},
  school      = {Universit{\"a}t Potsdam},
  year      = {2013},
  abstract  = {In children the way of life, nutrition and recreation changed in recent years and as a consequence body composition shifted as well. It is established that overweight belongs to a global problem. In addition, German children exhibit a less robust skeleton than ten years ago. These developments may elevate the risk of cardiovascular diseases and skeletal modifications. Heredity and environmental factors as nutrition, socioeconomic status, physical activity and inactivity influence fat accumulation and the skeletal system. Based on these negative developments associations between type of body shape, skeletal measures and physical activity; relations between external skeletal robustness, physical activity and inactivity, BMI and body fat and also the progress of body composition especially external skeletal robustness in comparison in Russian and German children were investigated. In a cross-sectional study 691 German boys and girls aged 6 to 10 years were examined. Anthropometric measurements were taken and questionnaires about physical activity and inactivity were answered by parents. Additionally, pedometers were worn to determinate the physical activity in children. To compare the body composition in Russian and German children data from the years 2000 and 2010 were used. The study has shown that pyknomorphic individuals exhibit the highest external skeletal robustness and leptomorphic ones the lowest. Leptomorphic children may have a higher risk for bone diseases in adulthood. Pyknomorphic boys are more physically active by tendency. This is assessed as positive because pyknomorphic types display the highest BMI and body fat. Results showed that physical activity may reduce BMI and body fat. In contrast physical inactivity may lead to an increase of BMI and body fat and may rise with increasing age. Physical activity encourages additionally a robust skeleton. Furthermore external skeletal robustness is associated with BMI in order that BMI as a measure of overweight should be consider critically. The international 10-year comparison has shown an increase of BMI in Russian children and German boys. Currently, Russian children exhibit a higher external skeletal robustness than the Germans. However, in Russian boys skeleton is less robust than ten years ago. This trend should be observed in the future as well in other countries. All in all, several measures should be used to describe health situation in children and adults. Furthermore, in children it is essential to support physical activity in order to reduce the risk of obesity and to maintain a robust skeleton. In this way diseases are able to prevent in adulthood.},
  language  = {en}
}
@article{MeyerErnstSchottetal.2015,
  author    = {Meyer, Ursina and Ernst, Dominique and Schott, Silvia and Riera, Claudia and Hattendorf, Jan and Romkes, Jacqueline and Granacher, Urs and G{\"o}pfert, Beat and Kriemler, Susi},
  title     = {Validation of two accelerometers to determine mechanical loading of physical activities in children},
  series = {Journal of sports sciences},
  volume    = {33},
  journal   = {Journal of sports sciences},
  number    = {16},
  publisher = {Routledge, Taylor \& Francis Group},
  address   = {Abingdon},
  issn      = {0264-0414},
  doi       = {10.1080/02640414.2015.1004638},
  pages     = {1702 -- 1709},
  year      = {2015},
  abstract  = {The purpose of this study was to assess the validity of accelerometers using force plates (i.e., ground reaction force (GRF)) during the performance of different tasks of daily physical activity in children. Thirteen children (10.1 (range 5.4-15.7)years, 3 girls) wore two accelerometers (ActiGraph GT3X+ (ACT), GENEA (GEN)) at the hip that provide raw acceleration signals at 100Hz. Participants completed different tasks (walking, jogging, running, landings from boxes of different height, rope skipping, dancing) on a force plate. GRF was collected for one step per trial (10 trials) for ambulatory movements and for all landings (10 trials), rope skips and dance procedures. Accelerometer outputs as peak loading (g) per activity were averaged. ANOVA, correlation analyses and Bland-Altman plots were computed to determine validity of accelerometers using GRF. There was a main effect of task with increasing acceleration values in tasks with increasing locomotion speed and landing height (P<0.001). Data from ACT and GEN correlated with GRF (r=0.90 and 0.89, respectively) and between each other (r=0.98), but both accelerometers consistently overestimated GRF. The new generation of accelerometer models that allow raw signal detection are reasonably accurate to measure impact loading of bone in children, although they systematically overestimate GRF.},
  language  = {en}
}
@article{SalzwedelRabeZahnetal.2017,
  author    = {Salzwedel, Annett and Rabe, Sophie and Zahn, Thomas and Neuwirth, Julia and Eichler, Sarah and Haubold, Kathrin and Wachholz, Anne and Reibis, Rona Katharina and V{\"o}ller, Heinz},
  title     = {User Interest in Digital Health Technologies to Encourage Physical Activity},
  series = {JMIR. Mhealth \& Uhealth},
  volume    = {5},
  journal   = {JMIR. Mhealth \& Uhealth},
  number    = {4},
  publisher = {JMIR Publications},
  address   = {Toronto},
  doi       = {10.2196/mhealth.7192},
  year      = {2017},
  abstract  = {Background: Although the benefits for health of physical activity (PA) are well documented, the majority of the population is unable to implement present recommendations into daily routine. Mobile health (mHealth) apps could help increase the level of PA. However, this is contingent on the interest of potential users. Objective: The aim of this study was the explorative, nuanced determination of the interest in mHealth apps with respect to PA among students and staff of a university. Methods: We conducted a Web-based survey from June to July 2015 in which students and employees from the University of Potsdam were asked about their activity level, interest in mHealth fitness apps, chronic diseases, and sociodemographic parameters. Results: A total of 1217 students (67.30\%, 819/1217; female; 26.0 years [SD 4.9]) and 485 employees (67.5\%, 327/485; female; 42.7 years [SD 11.7]) participated in the survey. The recommendation for PA (3 times per week) was not met by 70.1\% (340/485) of employees and 52.67\% (641/1217) of students. Within these groups, 53.2\% (341/641 students) and 44.2\% (150/340 employees)—independent of age, sex, body mass index (BMI), and level of education or professional qualification—indicated an interest in mHealth fitness apps. Conclusions: Even in a younger, highly educated population, the majority of respondents reported an insufficient level of PA. About half of them indicated their interest in training support. This suggests that the use of personalized mobile fitness apps may become increasingly significant for a positive change of lifestyle.},
  language  = {en}
}
@misc{SalzwedelRabeZahnetal.2017,
  author    = {Salzwedel, Annett and Rabe, Sophie and Zahn, Thomas and Neuwirth, Julia and Eichler, Sarah and Haubold, Kathrin and Wachholz, Anne and Reibis, Rona Katharina and V{\"o}ller, Heinz},
  title     = {User Interest in Digital Health Technologies to Encourage Physical Activity},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-401872},
  pages     = {8},
  year      = {2017},
  abstract  = {Background: Although the benefits for health of physical activity (PA) are well documented, the majority of the population is unable to implement present recommendations into daily routine. Mobile health (mHealth) apps could help increase the level of PA. However, this is contingent on the interest of potential users. Objective: The aim of this study was the explorative, nuanced determination of the interest in mHealth apps with respect to PA among students and staff of a university. Methods: We conducted a Web-based survey from June to July 2015 in which students and employees from the University of Potsdam were asked about their activity level, interest in mHealth fitness apps, chronic diseases, and sociodemographic parameters. Results: A total of 1217 students (67.30\%, 819/1217; female; 26.0 years [SD 4.9]) and 485 employees (67.5\%, 327/485; female; 42.7 years [SD 11.7]) participated in the survey. The recommendation for PA (3 times per week) was not met by 70.1\% (340/485) of employees and 52.67\% (641/1217) of students. Within these groups, 53.2\% (341/641 students) and 44.2\% (150/340 employees)—independent of age, sex, body mass index (BMI), and level of education or professional qualification—indicated an interest in mHealth fitness apps. Conclusions: Even in a younger, highly educated population, the majority of respondents reported an insufficient level of PA. About half of them indicated their interest in training support. This suggests that the use of personalized mobile fitness apps may become increasingly significant for a positive change of lifestyle.},
  language  = {en}
}
@misc{BordeSmithSutherlandetal.2017,
  author    = {Borde, Ron and Smith, Jordan J. and Sutherland, Rachel and Nathan, Nicole and Lubans, David Revalds},
  title     = {Methodological considerations and impact of school-based interventions on objectively measured physical activity in adolescents: a systematic review and meta-analysis},
  series = {Obesity reviews : an official journal of the International Association for the Study of Obesity},
  volume    = {18},
  journal   = {Obesity reviews : an official journal of the International Association for the Study of Obesity},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {1467-7881},
  doi       = {10.1111/obr.12517},
  pages     = {476 -- 490},
  year      = {2017},
  abstract  = {Objective: The aims of this systematic review and meta-analysis are (i) to determine the impact of school-based interventions on objectively measured physical activity among adolescents and (ii) to examine accelerometer methods and decision rule reporting in previous interventions. Methods: A systematic search was performed to identify randomized controlled trials targeting adolescents (age: >= 10 years), conducted in the school setting, and reporting objectively measured physical activity. Random effects meta-analyses were conducted to determine the pooled effects of previous interventions on total and moderate-to-vigorous physical activity. Potential moderators of intervention effects were also explored. Results: Thirteen articles met the inclusion criteria, and twelve were included in the meta-analysis. The pooled effects were small and non-significant for both total physical activity (standardized mean difference = 0.02 [95\% confidence interval = -0.13 to 0.18]) and moderate-to-vigorous physical activity (standardized mean difference = 0.24 [95\% confidence interval = -0.08 to 0.56]). Sample age and accelerometer compliance were significant moderators for total physical activity, with a younger sample and higher compliance associated with larger effects. Conclusion: Previous school-based physical activity interventions targeting adolescents have been largely unsuccessful, particularly for older adolescents. There is a need for more high-quality research using objective monitoring in this population. Future interventions should comply with best-practice recommendations regarding physical activity monitoring protocols.},
  language  = {en}
}
@misc{JekaucBrand2017,
  author    = {Jekauc, Darko and Brand, Ralf},
  title     = {Editorial: How do Emotions and Feelings Regulate Physical Activity?},
  series = {Frontiers in psychology},
  volume    = {8},
  journal   = {Frontiers in psychology},
  publisher = {Frontiers Research Foundation},
  address   = {Lausanne},
  issn      = {1664-1078},
  doi       = {10.3389/fpsyg.2017.01145},
  pages     = {3},
  year      = {2017},
  language  = {en}
}
@misc{WippertWiebking2018,
  author    = {Wippert, Pia-Maria and Wiebking, Christine},
  title     = {Stress and Alterations in the Pain Matrix},
  series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe},
  number    = {438},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-412058},
  pages     = {11},
  year      = {2018},
  abstract  = {The genesis of chronic pain is explained by a biopsychosocial model. It hypothesizes an interdependency between environmental and genetic factors provoking aberrant long-term changes in biological and psychological regulatory systems. Physiological effects of psychological and physical stressors may play a crucial role in these maladaptive processes. Specifically, long-term demands on the stress response system may moderate central pain processing and influence descending serotonergic and noradrenergic signals from the brainstem, regulating nociceptive processing at the spinal level. However, the underlying mechanisms of this pathophysiological interplay still remain unclear. This paper aims to shed light on possible pathways between physical (exercise) and psychological stress and the potential neurobiological consequences in the genesis and treatment of chronic pain, highlighting evolving concepts and promising research directions in the treatment of chronic pain. Two treatment forms (exercise and mindfulness-based stress reduction as exemplary therapies), their interaction, and the dose-response will be discussed in more detail, which might pave the way to a better understanding of alterations in the pain matrix and help to develop future prevention and therapeutic concepts},
  language  = {en}
}