@misc{NevillNegraMyersetal.2021, author = {Nevill, Alan M. and Negra, Yassine and Myers, Tony D. and Duncan, Michael J. and Chaabene, Helmi and Granacher, Urs}, title = {Are Early or Late Maturers Likely to Be Fitter in the General Population?}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {695}, issn = {1866-8364}, doi = {10.25932/publishup-48992}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-489928}, pages = {18}, year = {2021}, abstract = {The present study aims to identify the optimal body-size/shape and maturity characteristics associated with superior fitness test performances having controlled for body-size, sex, and chronological-age differences. The sample consisted of 597 Tunisian children (396 boys and 201 girls) aged 8 to 15 years. Three sprint speeds recorded at 10, 20 and 30 m; two vertical and two horizontal jump tests; a change-of-direction and a handgrip-strength tests, were assessed during physical-education classes. Allometric modelling was used to identify the benefit of being an early or late maturer. Findings showed that being tall and light is the ideal shape to be successful at most physical fitness tests, but the height-to-weight "shape" ratio seems to be test-dependent. Having controlled for body-size/shape, sex, and chronological age, the model identified maturity-offset as an additional predictor. Boys who go earlier/younger through peak-height-velocity (PHV) outperform those who go at a later/older age. However, most of the girls' physical-fitness tests peaked at the age at PHV and decline thereafter. Girls whose age at PHV was near the middle of the age range would appear to have an advantage compared to early or late maturers. These findings have important implications for talent scouts and coaches wishing to recruit children into their sports/athletic clubs.}, language = {en} } @misc{GebelLuederGranacher2019, author = {Gebel, Arnd and L{\"u}der, Benjamin and Granacher, Urs}, title = {Effects of Increasing Balance Task Difficulty on Postural Sway and Muscle Activity in Healthy Adolescents}, series = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe}, number = {583}, issn = {1866-8364}, doi = {10.25932/publishup-43921}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-439211}, pages = {15}, year = {2019}, abstract = {Evidence-based prescriptions for balance training in youth have recently been established. However, there is currently no standardized means available to assess and quantify balance task difficulty (BTD). Therefore, the objectives of this study were to examine the effects of graded BTD on postural sway, lower limb muscle activity and coactivation in adolescents. Thirteen healthy high-school students aged 16 to 17 volunteered to participate in this cross-sectional study. Testing involved participants to stand on a commercially available balance board with an adjustable pivot that allowed six levels of increasing task difficulty. Postural sway [i.e., total center of pressure (CoP) displacements] and lower limb muscle activity were recorded simultaneously during each trial. Surface electromyography (EMG) was applied in muscles encompassing the ankle (m. tibialis anterior, medial gastrocnemius, peroneus longus) and knee joint (m. vastus medialis, biceps femoris). The coactivation index (CAI) was calculated for ankle and thigh muscles. Repeated measures analyses of variance revealed a significant main effect of BTD with increasing task difficulty for postural sway (p < 0.001; d = 6.36), muscle activity (p < 0.001; 2.19 < d < 4.88), and CAI (p < 0.001; 1.32 < d < 1.41). Multiple regression analyses showed that m. tibialis anterior activity best explained overall CoP displacements with 32.5\% explained variance (p < 0.001). The observed increases in postural sway, lower limb muscle activity, and coactivation indicate increasing postural demands while standing on the balance board. Thus, the examined board can be implemented in balance training to progressively increase BTD in healthy adolescents.}, language = {en} } @misc{PutaSteidtenBaumbachetal.2018, author = {Puta, Christian and Steidten, Thomas and Baumbach, Philipp and W{\"o}hrl, Toni and May, Rico and Kellmann, Michael and Herbsleb, Marco and Gabriel, Brunhild and Weber, Stephanie and Granacher, Urs and Gabriel, Holger H. W.}, title = {Standardized assessment of resistance training}, series = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe}, number = {542}, issn = {1866-8364}, doi = {10.25932/publishup-42628}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-426289}, pages = {11}, year = {2018}, abstract = {From a health and performance-related perspective, it is crucial to evaluate subjective symptoms and objective signs of acute training-induced immunological responses in young athletes. The limited number of available studies focused on immunological adaptations following aerobic training. Hardly any studies have been conducted on resistance-training induced stress responses. Therefore, the aim of this observational study was to investigate subjective symptoms and objective signs of immunological stress responses following resistance training in young athletes. Fourteen (7 females and 7 males) track and field athletes with a mean age of 16.4 years and without any symptoms of upper or lower respiratory tract infections participated in this study. Over a period of 7 days, subjective symptoms using the Acute Recovery and Stress Scale (ARSS) and objective signs of immunological responses using capillary blood markers were taken each morning and after the last training session. Differences between morning and evening sessions and associations between subjective and objective parameters were analyzed using generalized estimating equations (GEE). In post hoc analyses, daily change-scores of the ARSS dimensions were compared between participants and revealed specific changes in objective capillary blood samples. In the GEE models, recovery (ARSS) was characterized by a significant decrease while stress (ARSS) showed a significant increase between morning and evening-training sessions. A concomitant increase in white blood cell count (WBC), granulocytes (GRAN) and percentage shares of granulocytes (GRAN\%) was found between morning and evening sessions. Of note, percentage shares of lymphocytes (LYM\%) showed a significant decrease. Furthermore, using multivariate regression analyses, we identified that recovery was significantly associated with LYM\%, while stress was significantly associated with WBC and GRAN\%. Post hoc analyses revealed significantly larger increases in participants' stress dimensions who showed increases in GRAN\%. For recovery, significantly larger decreases were found in participants with decreases in LYM\% during recovery. More specifically, daily change-scores of the recovery and stress dimensions of the ARSS were associated with specific changes in objective immunological markers (GRAN\%, LYM\%) between morning and evening-training sessions. Our results indicate that changes of subjective symptoms of recovery and stress dimensions using the ARSS were associated with specific changes in objectively measured immunological markers.}, language = {en} } @misc{Rollfing2018, type = {Master Thesis}, author = {Rollfing, Petra}, title = {Kommunale Kinder- und Jugendgremien im Land Brandenburg}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-419645}, school = {Universit{\"a}t Potsdam}, pages = {III, 115}, year = {2018}, abstract = {Kommunale Kinder- und Jugendgremien sind eine M{\"o}glichkeit, junge Menschen in der Kommune zu beteiligen. Die Masterarbeit besch{\"a}ftigt sich mit den kommunalen Kinder- und Jugendgremien im Land Brandenburg, {\"u}ber die es in der wissenschaftlichen Literatur nur wenige Erkenntnisse gibt. Die Arbeit gibt einen {\"U}berblick {\"u}ber die bestehenden Gremien und zeigt, welche Kinder und Jugendliche sich beteiligen und wie der Entwicklungsstand der Gremien ist. Ausgehend von der Partizipationsleiter von Hart geht die Arbeit zudem in zwei Fallstudien in Senftenberg und Oranienburg der Frage nach, ob es sich bei den Kinder- und Jugendgremien um ernstgemeinte Partizipation handelt.}, language = {de} } @misc{SlimaniParavlicGranacher2018, author = {Slimani, Maamer and Paravlic, Armin and Granacher, Urs}, title = {A Meta-Analysis to Determine Strength Training Related Dose-Response Relationships for Lower-Limb Muscle Power Development in Young Athletes}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {472}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-417738}, pages = {14}, year = {2018}, abstract = {It is well-documented that strength training (ST) improves measures of muscle strength in young athletes. Less is known on transfer effects of ST on proxies of muscle power and the underlying dose-response relationships. The objectives of this meta-analysis were to quantify the effects of ST on lower limb muscle power in young athletes and to provide dose-response relationships for ST modalities such as frequency, intensity, and volume. A systematic literature search of electronic databases identified 895 records. Studies were eligible for inclusion if (i) healthy trained children (girls aged 6-11 y, boys aged 6-13 y) or adolescents (girls aged 12-18 y, boys aged 14-18 y) were examined, (ii) ST was compared with an active control, and (iii) at least one proxy of muscle power [squat jump (SJ) and countermovement jump height (CMJ)] was reported. Weighted mean standardized mean differences (SMDwm) between subjects were calculated. Based on the findings from 15 statistically aggregated studies, ST produced significant but small effects on CMJ height (SMDwm = 0.65; 95\% CI 0.34-0.96) and moderate effects on SJ height (SMDwm = 0.80; 95\% CI 0.23-1.37). The sub-analyses revealed that the moderating variable expertise level (CMJ height: p = 0.06; SJ height: N/A) did not significantly influence ST-related effects on proxies of muscle power. "Age" and "sex" moderated ST effects on SJ (p = 0.005) and CMJ height (p = 0.03), respectively. With regard to the dose-response relationships, findings from the meta-regression showed that none of the included training modalities predicted ST effects on CMJ height. For SJ height, the meta-regression indicated that the training modality "training duration" significantly predicted the observed gains (p = 0.02), with longer training durations (>8 weeks) showing larger improvements. This meta-analysis clearly proved the general effectiveness of ST on lower-limb muscle power in young athletes, irrespective of the moderating variables. Dose-response analyses revealed that longer training durations (>8 weeks) are more effective to improve SJ height. No such training modalities were found for CMJ height. Thus, there appear to be other training modalities besides the ones that were included in our analyses that may have an effect on SJ and particularly CMJ height. ST monitoring through rating of perceived exertion, movement velocity or force-velocity profile could be promising monitoring tools for lower-limb muscle power development in young athletes.}, language = {en} } @misc{GolleGranacherHoffmannetal.2014, author = {Golle, Kathleen and Granacher, Urs and Hoffmann, Martin and Wick, Ditmar and M{\"u}hlbauer, Thomas}, title = {Effect of living area and sports club participation on physical fitness in children}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-401418}, pages = {8}, year = {2014}, abstract = {Background: Cross-sectional studies detected associations between physical fitness, living area, and sports participation in children. Yet, their scientific value is limited because the identification of cause-and-effect relationships is not possible. In a longitudinal approach, we examined the effects of living area and sports club participation on physical fitness development in primary school children from classes 3 to 6. Methods: One-hundred and seventy-two children (age: 9-12 years; sex: 69 girls, 103 boys) were tested for their physical fitness (i.e., endurance [9-min run], speed [50-m sprint], lower- [triple hop] and upper-extremity muscle strength [1-kg ball push], flexibility [stand-and-reach], and coordination [star coordination run]). Living area (i.e., urban or rural) and sports club participation were assessed using parent questionnaire. Results: Over the 4 year study period, urban compared to rural children showed significantly better performance development for upper- (p = 0.009, ES = 0.16) and lower-extremity strength (p < 0.001, ES = 0.22). Further, significantly better performance development were found for endurance (p = 0.08, ES = 0.19) and lower-extremity strength (p = 0.024, ES = 0.23) for children continuously participating in sports clubs compared to their non-participating peers. Conclusions: Our findings suggest that sport club programs with appealing arrangements appear to represent a good means to promote physical fitness in children living in rural areas.}, language = {en} } @phdthesis{Fricke2012, author = {Fricke, Caroline}, title = {Politisch bedingte Konflikte von Jugendlichen im Bezirk Schwerin 1971 - 1989}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-71090}, school = {Universit{\"a}t Potsdam}, year = {2012}, abstract = {„Alle Kinder m{\"u}ssen zu wertvollen Menschen erzogen werden", forderte Margot Honecker, Erziehungsminister der DDR von 1963 bis 1989. W{\"a}hrend liberale Jugendsoziologen die Jugendphase als Moratorium begreifen und damit Heranwachsenden Freir{\"a}ume zubilligen, geltende soziale Normen infrage zu stellen und selbstbestimmte Lebensentw{\"u}rfe zu erproben, ohne ihr Handeln in gleicher Weise verantworten zu m{\"u}ssen wie Erwachsene, wurden Jugendliche in der DDR danach beurteilt, inwieweit sie dem Ideal der „allseitig gebildeten sozialistischen Pers{\"o}nlichkeit" entsprachen. Nach Honeckers Ansicht w{\"a}re die freie Entfaltung des Individuums erst im Kommunismus m{\"o}glich. Individuelle Entfaltung besaß f{\"u}r sie keinen eigenen Wert. Der politische Erziehungsanspruch erstreckte sich grunds{\"a}tzlich auf alle Lebenswelten von Jugendlichen. Freir{\"a}ume zur Selbstentfaltung waren in der DDR sowohl materiell als auch ideell eng umgrenzt, ein Umstand den der bundesdeutsche Bildungssoziologe J{\"u}rgen Zinnecker als „Jugendmoratorium in kasernierter Form" bezeichnete. Dem politischen Anpassungsdruck waren Kinder und Jugendliche in besonders starkem Maße ausgesetzt. Zwar richtete sich der Erziehungsanspruch der SED grunds{\"a}tzlich auf alle B{\"u}rger, doch anders als Erwachsene hatten Kinder und Jugendliche noch keine eigenst{\"a}ndige Stellung innerhalb des sozialen und gesellschaftlichen Gef{\"u}ges gefunden und deshalb weniger M{\"o}glichkeiten, sich der politischen Einwirkung zu entziehen. Mit dem Jugendgesetz von 1974 wurde die sozialistische Pers{\"o}nlichkeit als Erziehungsziel festgelegt, dem auch die Eltern zu folgen hatten. Bildungschancen wurden schon fr{\"u}hzeitig von der Anpassung an vorgegebene Normen abh{\"a}ngig gemacht, abweichendes Verhalten konnte rigide bestraft werden und gravierende Folgen f{\"u}r den weiteren Lebensweg haben. Auch wenn die meisten Jugendlichen die Forderungen des Staates zu erf{\"u}llen schienen und ihre Verbundenheit mit der Politik der SED wann immer gefordert bezeugten, standen sie dieser Politik tats{\"a}chlich mindestens gleichg{\"u}ltig gegen{\"u}ber. Der „Widerspruch zwischen Wort und Tat" war eines der gravierenden Probleme der Herrschenden im Umgang mit Heranwachsenden. Es gab aber auch Jugendliche, die bewusst Einschr{\"a}nkungen in Kauf nahmen, um ihre Vorstellungen eines selbstbestimmten Lebens verwirklichen zu k{\"o}nnen. Schon bei geringf{\"u}giger Abweichung von ausdr{\"u}cklichen oder unausgesprochenen Vorgaben mussten sie mit erheblichen staatlichen Eingriffen in ihr pers{\"o}nliches Dasein rechnen. Die {\"a}ußerste Form der Abweichung waren Ausreiseersuchen und Fluchtversuche. Jugendliche waren unter Antragstellern und „Republikfl{\"u}chtigen" {\"u}berproportional vertreten. Die Dissertation beleuchtet das Spannungsverh{\"a}ltnis zwischen staatlich vorgegebenen Lebenswegen und eigen-sinniger Gestaltung verschiedener Lebensbereiche von Kindern und Jugendlichen f{\"u}r die Jahre der Honecker-Herrschaft zwischen 1971 bis 1989 im Bezirk Schwerin.}, language = {de} }