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Beach handball athletes experience an overlap during their preparation phase for the beach and the indoor season for several weeks. This transition phase from playing on an indoor surface to a sand surface is crucial for players’ performance levels both on the sand and indoor surfaces, but coaches and athletes alike are concerned about possible performance impairments when training on a sand surface while still playing indoors. Therefore, we aimed to evaluate the effects of a specific transition phase from the indoor to the beach season in elite beach handball athletes. With 29 elite athletes participating in the study, we evaluated their jumping (countermovement and drop jump) and sprinting (5–10–20 m) performances and conducted a handball-specific agility test on both rigid and sand surfaces. In addition, we evaluated a drop long jump on a sand surface. Vertical jumping performance was analyzed using a 3D marker-based system on both rigid and sand surfaces under standardized laboratory conditions. All tests took place directly before and after a 6-week intervention program. The results showed that athletes in the intervention group significantly improved their performance in jumping (countermovement and drop long jump) compared to the control group. Furthermore, performance on a rigid surface was not only maintained for all tests but also significantly increased for the countermovement jump. Therefore, the intervention program is effective at improving performance during the transition from indoor to beach seasons without impairing indoor performance.

In response to the Coronavirus Disease 2019 (COVID-19) pandemic, various measures were taken to contain its spread, including restrictions on physical education and sports clubs. These measures substantially limited children's physical activity behaviors and may have compromised their motor development. Such compromising effects may be particularly prevalent among children from lower socioeconomic background (SEB) who tend to be less physically active than higher SEB peers. In this study, the impact of COVID-19 pandemic-related restrictions on children's motor development was investigated with respect to children's SEB within the PESCov DFG project. Data from 68,996 children from a metropolitan region in Germany (Age: 8.83 years +- 0.56, range: 6.4-13 years, 35,270 female, 51.1 %) assessed between 2011/2012 and 2022/2023 were analyzed as part of the longitudinal cohort study “Berlin hat Talent”. Assessment took place before and after the onset of the pandemic using the German Motor Fitness Test. The test includes assessments of various motor skills covering endurance, strength, coordination, and flexibility. Demographic variables (e.g., age, gender) were collected via questionnaires. SEB was derived on school level, which was determined using the official school type classifications of the state of Berlin. Cross-classified linear mixed effect models were fitted to account for hierarchies in the data, with individual test values (level 1) being nested in motor domains (level 2a) and in participants (level 2b) and participants being nested in schools (level 3b). Outcome measure was motor skill performance transformed from German reference percentiles to z-scores per motor skill. The effects of Time (pre, post LD I, post LD II), Motor Domain, and SEB (continuous, -2 - 2) were estimated while controlling for Age, Gender, and Secular Trends. Main effects of Motor Domain, Time, and SEB were significant. Further, a significant Time x Motor Domain interaction revealed that motor skills differentially developed from during the pandemic. Coordination, strength, and flexibility decreased, while endurance increased. SEB had a negative effect on overall motor development of third graders. However, this effect varied between motor domains (coordination = endurance > strength > flexibility). Totally, motor skills were on average about 4 percentile points lower after lockdown I, and the effect of the pandemic was stronger after controlling for secular trend. Results suggest highly differential effects of the pandemic on children's motor development, which should be considered when recovering motor skills in the post-pandemic era. To avert these trends and the lifelong consequences of impaired motor development in childhood, comprehensive monitoring of children’s motor performance levels is needed as well as support programs for children with compromised motor performance, particularly for children from low SEBs.

Childhood obesity is associated with various adverse health outcomes. Restrictive measures to contain the spread of the Coronavirus Disease 2019 (COVID-19) pandemic, like lockdowns and school closures, affected children’s daily structure, physical activity, dietary habits, and sleep quality, possibly exacerbating risk factors for childhood obesity and higher body mass index (BMI) in children. In particular, as poor socioeconomic conditions tend to favor obesogenic environments, children from lower socioeconomic backgrounds (SEBs) may have been at relatively higher risk for elevated BMI levels following pandemic measures. In this study, the impact of measures related to the COVID-19 pandemic on the BMI of third graders was investigated with regard to children’s SEB. Data from 41,728 children (8.84 ± 0.56 years, 20,431 female) were collected in the context of the longitudinal cohort study “Berlin hat Talent” and analyzed as part of the PESCov DFG project. Children were tested either before the pandemic (preCOVID: Sept2017 - March2020, n = 26,314), or following the first (post_"LD I" : Aug2020 - Dec2020, n = 6,657) or second lockdown in Germany (post_"LD II" : Aug2021 - Jan2022, n = 8,757). Demographic variables were collected via questionnaires. SEB was based on the official school type classification of the state of Berlin. Linear mixed effect models were computed to account for the hierarchical nature of the data, i.e. children (level 1) nested in schools (level 2). Outcome measures were age- and sex-adjusted BMI standard deviation scores (SDS). Independent variables were Time (preCOVID, post_"LD I" , post_"LD II" ), SEB (continuous, -2 - 2), and the interaction thereof. Covariates were Age, Gender, and Month of Test. Significant effects of Time (p < .05) and SEB (p < .001) revealed elevated BMIs in post_"LD I" and post_"LD II" compared to preCOVID cohorts and higher BMIs for children with lower SEB. A significant Time x SEB interaction (p < .01) indicated that the effect of SEB on children’s BMI increased in response to lockdowns, especially in post_"LD II" . Results suggest that the COVID-19-related measures lead to increased BMI in children, and that children of lower SEB were at particular risk for higher BMIs following lockdowns. These findings denote an alarming trend and emphasize the necessity for countermeasures to reduce lockdown-related BMI increments in children, particularly in low SEB areas. Authorities are called into action to promote physical activity of children and establish post-pandemic offers to counteract the risk of increasing rates of childhood obesity and related adverse health outcomes.

Zusammenfassung Hintergrund Im Sport wird angenommen, dass ein dynamischer Knievalgus bei einbeinigen Landungen einen relevanten Verletzungsmechanismus des vorderen Kreuzbands darstellt. Während bestehende effektive Präventionsprogramme zur Reduktion des Knievalgus primär auf die Verbesserung allgemeiner konditioneller und/oder koordinativer Einflussgrößen ausgerichtet sind, fokussiert ein Video-Feedback-Training die Korrektur individueller Defizite in der sportlichen Technik, um u. a. ein potenzielles Verletzungsrisiko zu reduzieren. Ziel Evaluation der kurz- und insbesondere mittel- und langfristigen Wirksamkeit eines Video-Feedback-Trainings zur Veränderung des frontalen Kniewinkels bei einbeinigen Landungen. Methode Im Rahmen einer exploratorischen Studie wurden 10 sportlich aktive Personen (Alter: 25 ± 5 Jahre, Größe: 170,8 ± 4,5 cm) getestet. Diese führten in Anlehnung an das Landing Error Scoring System (LESS-Test) einbeinige Drop-Jumps in einem Pretest, in einer Aneignungsphase mit Video-Feedback und 2 Retentionstests 2 und 6 Wochen nach der Aneignungsphase ohne Video-Feedback aus. Das Video-Feedback wurde in der Aneignungsphase bei jedem zweiten Sprung und zusätzlich selbstbestimmt auf Nachfrage über ein Expertenmodell mit neutraler Kniestellung im Overlay-Modus aus der Frontalperspektive gegeben. Ergebnisse Die Ergebnisse wurden nach Sprung- und Nichtsprungbein der Proband*innen differenziert. Sie zeigen eine bedeutsame Verringerung des frontalen Kniewinkels für das Sprungbein (F1, 9 = 10,43, p = 0,01, η2 p = 0,54, 95 % CI [0,04; 0,74]) bei einbeinigen Landungen in der Aneignungsphase, jedoch keine statistisch bedeutsame Verringerung für das Nichtsprungbein (F1, 9 = 4,07, p = 0,08, η2 p = 0,31, 1-β = 0,44). Im Retentionstest nach 6 Wochen nähert sich der frontale Kniewinkel beidseitig dem Ausgangsniveau aus dem Pretest wieder an. Schlussfolgerung Ein Video-Feedback-Training bietet sich als einfach durchzuführendes, alternatives Verletzungspräventionsprogramm an. Eine fehlende mittel- und langfristige Veränderung und hohe Variabilität des frontalen Kniewinkels lassen eine mehrfache und/oder regelmäßige Durchführung eines Video-Feedback-Trainings sinnvoll erscheinen. In weiteren Studien mit Kontrollgruppendesign und unterschiedlichen Feedback-Prozeduren wird systematisch zu prüfen sein, ob eine längerfristige Reduktion eines potenziellen Verletzungsrisikos des vorderen Kreuzbands erreicht werden kann.

Dynamic postural control is one of the essential factors in situations where non-contact injuries mainly occur, i.e., landing, cutting, or stopping. Therefore, testing of dynamic postural control should be implemented in injury risk assessment. Moreover, non-contact injuries mainly occur under loaded conditions when the athlete is physically stressed. Therefore, risk factors and mechanisms of these injuries should also be regarded under loading conditions and not only when the athlete is recovered. Current studies examining the influence of physical load on risk factors, such as dynamic postural control, often use cycling protocols to stress the participants. Nevertheless, most types of sports require running as a central element and the induced internal load after cycling might not be the same after running. Therefore, the current study aimed to examine the influence of a running and a cycling protocol on dynamic postural control and to determine the potential injury risk under representative conditions. In total, 128 sport students (64 males and 64 females, age: 23.64 ± 2.44, height: 176.54 ± 8.96 cm, weight: 68.85 ± 10.98 kg) participated in the study. They were tested with the Y Balance Test before and after one loading protocol. A total of 64 participants completed a protocol on a cycle ergometer and the other 64 on a treadmill. A mixed ANOVA showed significant interactions of time and load type. Dynamic postural control was reduced immediately after cycling but did not change after running. These findings indicate a load type dependence of dynamic postural control that must be considered while assessing an athlete’s potential injury risk and they support the need for more representative designs.

Correct decision-making under physical load is a central challenge for referees in sports games. Handball referees are assumed to make both a decision (calling a foul or no foul) and to call its reasonings (type of foul, punishments). However, the impact of physical load on these two aspects has not been differentiated so far. Here, in two studies, we aimed to investigate the hypothesised impact of physical load on both referees’ decisions and reasonings. To this end, N = 66 (study 1) and N = 73 (study 2) top-class handball referees performed the Yo-Yo Intermittent Recovery Test combined with a video-based decision-making test. Referees’ decisions improved from initial to medium physical load and they deteriorated under maximal physical load in study 1, whereas in study 2 the quality of the decisions was constant across physical load conditions. The percent of correct reasonings decreased from initial to medium physical load in study 1, whereas the opposite pattern was found in study 2. In both studies, reasoning performance did not change from medium to maximal physical load. Moreover, referees demonstrated better endurance performance in study 2 than in study 1. Despite some methodological limitations (e.g. familiarisation with the experimental setup in referees who participated in both studies), the present findings tentatively indicate that a well-trained endurance capacity may support referees’ decision-making, i.e. to make correct decisions and reasonings. Specifically, enhanced endurance capacity may lead to lower subjectively perceived fatigue, resulting in larger cognitive capacities that may facilitate referees’ decision-making.

ZusammenfassungAufgrund ihrer Einfachheit und Nutzerfreundlichkeit wird für die Erfassung der subjektiven Beanspruchungswahrnehmung in Training und Wettkampf bevorzugt die Category Ratio Scale (CR10-Skala) oder eine daran angelehnte Ein-Item-Skala eingesetzt. Die CR10-Skala stellt eine nicht-lineare, leicht positiv beschleunigte Funktion bezogen auf die Beanspruchung dar, die in der autorisierten deutschen Fassung mit „Anstrengungsempfinden“ übersetzt wird. Allerdings ist festzuhalten, dass die existierenden Skalen keine vollständigen Stufenbezeichnungen beinhalten und/oder die Stufenbezeichnungen Überschneidungen mit verwandten Konstrukten, z. B. Ermüdung zulassen. Die Anstrengungsskala Sport (ASS) zeichnet sich demgegenüber durch vollständige Stufenbezeichnungen und begriffliche Klarheit mit der komparativen Deklination des Adjektivs anstrengend aus. Auf der Grundlage einer rationalen Konstruktionsstrategie sowie einer systematischen Item-Analyse kann gezeigt werden, dass die Voraussetzungen für die Verwendung der ASS als Verhältnisskala gegeben sind, die eine zuverlässige und inhaltlich eindeutige Messung der Anstrengung gestattet.

Verletzungen der ischiokruralen Muskulatur sind ein immer wiederkehrendes Thema im Sport. Sie sind schmerzhaft, häufig und bremsen die Karriere. Man kann daher nicht oft genug darüber schreiben, denn je mehr man darüber weiß, umso besser kann man damit umgehen – und das Risiko für solche Verletzungen vermindern.

Clinical Scenario: Reduced bone mineral density (BMD) is a serious condition in older adults. The mild form, osteopenia, is often a precursor of osteoporosis. Osteoporosis is a pathological condition and a global health problem as it is one of the most common diseases in developed countries. Finding solutions for prevention and therapy should be prioritized. Therefore, the critically appraised topic focuses on strength training as a treatment to counteract a further decline in BMD in older adults. Clinical Question: Is strength training beneficial in increasing BMD in older people with osteopenia or osteoporosis? Summary of Key Findings: Four of the 5 reviewed studies with the highest evidence showed a significant increase in lumbar spine BMD after strength training interventions in comparison with control groups. The fifth study confirmed the maintenance of lumbar spine density due to conducted exercises. Moreover, 3 reviewed studies revealed increasing BMD at the femoral neck after strength training when compared with controls, which appeared significant in 2 of them. Clinical Bottom Line: The findings indicate that strength training has a significant positive influence on BMD in older women (ie, postmenopausal) with osteoporosis or osteopenia. However, it is not recommended to only rely on strength training as the increase of BMD may not appear fast enough to reach the minimal desired values. A combination of strength training and supplements/medication seems most adequate. Generalization of the findings to older men with reduced BMD should be done with caution due to the lack of studies. Strength of Recommendation: There is grade B of recommendation to support the validity of strength training for older women in postmenopausal phase with reduced BMD.

Referees in sports games have a high level of responsibility as they have to make correct and appropriate decisions at any point during a match. Regarding referees’ decision-making (RDM) as a perceptual-cognitive process, evidence suggests that physical load might reduce cognitive performance and thus might reduce RDM performance as well. In consideration of increasing game dynamics, referees have to cope with high physical load, but they have to make correct and appropriate decisions further on. Here, we review the current state of research on the relationship between physical load and RDM. A scoping review was performed, in accordance with the PRISMA guidelines, using the following databases: Scopus, PubMed, Web of Science (all databases), SURF and SPONET (both with an English and German search). Only primary studies written in English or German that investigated the relationship between physical load and RDM in sports games were included. Eleven studies included in the review investigated six physical parameters and RDM: match period, velocity, blood lactate, running time, heart rate, distance covered. Most findings of the studies showed no relationship between physical load and RDM (n = 18). Thirteen findings suggest a negative relationship and three findings indicate a positive relationship between physical load and RDM. Results of the scoping review show contradictory evidence across and within investigated different physical parameters. As RDM consists of multi-factorial components, it is recommended to conduct systematic research programs – field as well as experimental studies – to resolve the missing control of potential confounding variables and to consider the difference of internal and external load.

Zum Talentscreening im Sport werden Testbatterien eingesetzt, die unterschiedliche sportmotorische Fertigkeiten sowie entwicklungsrelevante Parameter erheben. Standardauswertungsverfahren fuhren in der Regel zur Einordnung der Getesteten in zumeist funfstufige Leistungsklassen. Insbesondere bei grosen Stichproben werden allerdings Verfahrensweisen benotigt, die auch innerhalb der „besten Gruppe“ und „schwachsten Gruppe“ noch zuverlassig differenzieren. Dies gelingt z. B. im Projekt BERLIN HAT TALENT mit Verfahren, die auf multikriteriellen und unscharfen mathematischen Theorien und Methoden beruhen. Dabei ist hervorzuheben, dass subjektive Theorien und Wissensstande von Trainer*innen, Lehrer*innen und Sportwissenschaftler*innen explizit mit einbezogen werden konnen. Dies geschieht auf Basis diskursiver Validierungen und der Konstruktion von Bewertungsfunktionen, die auch als sogenannte Zugehorigkeitsfunktionen fur Fuzzy-Sets interpretiert werden konnen. Die vorgestellten multiattributiven Entscheidungsmodelle zeigen unter Einbeziehung des Expertenwissens den Mehrwert dieses Vorgehens auf und konnen mit Hilfe einer interaktiven Software transparent nachvollzogen werden.

Youth coaches take a significant role in the athlete’s network and represent an influencing factor on doping prevention, which has been investigated insufficiently by empirical research in young elite sports. Especially, combat sports are characterized by a multitude of doping opportunities to enhance the chance of winning. In order to deduce an effective and efficient doping prevention within the setting of combat sports, which is acknowledged by the protagonists, an examination of the coaches’ baseline concerning doping and prevention was assessed as a necessary precondition. Sixty-nine German coaches (89.9% male, 76.8% holding the highest license level in boxing, fencing, judo or wrestling) took part in an online survey, which focused on the coaches’ existing knowledge, doping perceptions, attitudes and prevention needs. The participating coaches in combat sports regard doping as an international problem. Independent of their type of sports, the coaches indicate a very critical position concerning doping attitudes and moral disengagement and indicate a satisfying knowledge concerning doping substances. Support is needed in the handling of supplements which are assumed to have a gateway function to doping. Several coaches request doping prevention on a regular basis that is embedded in their own coaching courses and tailored to their specific needs. Thus, participating coaches in combat sports have favorable preconditions in their interaction with young athletes and for the implementation and further expansion of doping prevention measures. Effectiveness of coaches’ doping prevention needs to be evaluated.

Anticipation in sports is commonly investigated using perception-action uncoupled methods, thus raising questions regarding transferability of findings to the field. The aim of this study was to investigate the influence of different degrees of perception-action coupling on anticipation in handball goalkeeping. Advanced, intermediate and novice handball goalkeepers watched videos of throws on the goal and were asked to anticipate throw direction via key press (perception-action artificial condition) and via natural movement response (perception-action simulated condition). Results reveal overall superior performance in the artificial compared to the simulated condition. Skill-based differences, however, were descriptively more pronounced in the simulated condition compared to the artificial condition. The findings further highlight the importance of more representative research methods to unravel perceptual-cognitive skill in sports.

Die Muskelkraft stellt eine wesentliche Grundlage der korperlichen Leistungsfahigkeit dar, um sport- und alltagsmotorische Bewegungsfertigkeiten zu erlernen, auszufuhren und zu verbessern. Gleichzeitig bedingt ein effektives und gesundheitsforderliches Training der Kraft eine korrekte Ausfuhrung der Trainingsubungen bzw. der Bewegungskoordination. Ohne ausreichende Kraft ware es auch nicht moglich, eine Ausdauerleistung okonomisch und gesundheitssteigernd zu erbringen. Die Diagnostik und das Training der Kraft sowie der Schnelligkeit, die eine aus Kraft und Koordination zusammengesetzte Einflussgrose der korperlichen Leistungsfahigkeit darstellt, sind bedeutsame Komponenten fur eine wunschenswerte langfristige korperliche Entwicklung von Kindern und Jugendlichen. In diesem Kapitel werden die wesentlichen Leistungs- und Entwicklungskriterien sowie Trainingsempfehlungen zusammengefasst.

Despite the importance of technique and tactics for athlete performance, there has been surprisingly little research on the value of these skills in talent identification and development. This study investigated the relationship between coaches' early notational analyses of female youth handball players and the long-term success of these athletes. Participants included sixty-eight female handball players involved in a talent selection camp in Germany when they were between 12 and 14 years of age (mean = 14.42

Background Non-contact injuries such as anterior cruciate ligament ruptures often occur during physical load toward the end of a match. This is ascribed to emerging processes due to exercise-induced fatigue. Moreover, non-contact injuries often occur during dynamic actions such as landing or cutting movements. Inter-limb asymmetries are suggested as one possible cause for those injuries based on findings indicating that asymmetries between limbs are associated with a higher injury risk. Hence, assessing inter-limb asymmetry during physical load in the condition of exercise-induced fatigue is warranted to identify potentially relevant precursors for non-contact injuries. Objective The objective of this study was to overview the current state of evidence concerning the influence of exercise-induced fatigue on inter-limb asymmetries through a systematic review. Methods A systematic literature search was conducted using the databases Web of Science, Scopus, PubMed, SURF, and SPONET to identify studies that assessed inter-limb asymmetries of healthy people, calculated with an asymmetry equation, before and after, or during a loading protocol. Results Thirteen studies were included in the systematic review. The loading protocols involved running, race walking, jumping, squatting, soccer, rowing, and combinations of different exercises. Moreover, different tasks/procedures were used to assess inter-limb asymmetries, e.g., squats, single-leg countermovement jumps, gait analysis, or isokinetic strength testing. The results seem to depend on the implemented loading protocol, the tasks/procedures, and the measured parameters. Conclusions Future research needs more systematization and consistency, assessing the effect of exercise-induced fatigue on inter-limb asymmetries. Moreover, the emergence of inter-limb asymmetries should be regarded in the context of sport-specific movements/tasks. Testing before, after, and during a physical loading protocol is advisable to consider the influence of exercise-induced fatigue on sport-specific tasks and to identify the possible mechanisms underlying load-dependent inter-limb asymmetries with regard to risk of non-contact injury.

Fitness training to attain the lean body ideal is becoming increasingly popular among women. However, it remains unclear how the drive for leanness (DL), as compared to the drives for thinness (DT) and muscularity (DM), relates to body image pathology and substance use in female weight-trainers. Participants (N = 168) completed a survey assessing DL, DT, DM, eating and body dysmorphic disorder pathology, and substance use. DT and DM were related to eating disorder and body dysmorphic disorder symptoms (allr ≥ .29; allps r = .19,p r = .17 and .55; bothp r ≥ .21; bothp

Kontinuierliches Monitoring physischer Fitness im Kindesalter ist aus gesellschaftlicher sowie individueller Perspektive bedeutsam, um eine gesunde kindliche Entwicklung zu unterstutzen. Entsprechend wird von der Kultusministerkonferenz (KMK) und dem Deutschen Olympischen Sportbund (DOSB) in gemeinsamen Handlungsempfehlungen (2017, S. 9) der Einsatz motorischer Tests im Schulsport empfohlen, um aus verschiedenen Perspektiven bedarfsorientiert Interventionsmasnahmen ableiten zu konnen. Motorische Testergebnisse werden in Leistungsklassen kategorisiert, um zu vermeiden, dass deskriptive, aber inhaltlich nicht bedeutsame Verbesserungen oder Verschlechterungen zwischen und innerhalb von Personen uberinterpretiert werden. Veranderungen der durchschnittlichen Leistungsfahigkeit uber mehrere Jahre hinweg konnen die Validitat dieser Referenzkategorien beeinflussen. Ziele dieser Studie sind daher, (1) mittelfristige zeitliche Leistungsveranderungen der physischen Fitness im mittleren Kindesalter aufzuzeigen, (2) Auswirkungen von Leistungsveranderungen auf Referenzwerte und die Validitat des Konstrukts physische Fitness zu prufen und (3) valide Referenzwerte fur Acht- und Neunjahrige zur Verfugung zu stellen. Von 2011 bis 2016 nahmen in einem quasilangsschnittlichen Design uber 20.000 DrittklasslerInnen im Projekt „Berlin hat Talent“ am Deutschen Motorik-Test 6–18 teil. Die zeitliche Stabilitat sportmotorischer Leistungen wird mittels Regressionsmodellen und Kreuztabellen gepruft sowie Auswirkungen auf die Konstruktvaliditat der bestehenden Berliner Referenzwerte mittels ordinaler Rasch-Modelle analysiert. Sieben der acht Testaufgaben zeigen zeitlich positive sowie negative Veranderungen. Die Konstruktvaliditat des Deutschen Motorik-Tests kann fur DrittklasslerInnen nach Ausschluss des Items „Balancieren ruckwarts“ bestatigt werden (p > 0,90). Die aufgabenspezifischen Veranderungen der motorischen Leistungsfahigkeit von Kindern in einem relativ kurzen Zeitraum unterstutzen zum einen die Forderung eines flachendeckenden und kontinuierlichen Monitorings, um fruhzeitig Interventionsmasnahmen einleiten zu konnen, und bedingen zum anderen eine kontinuierliche Prufung bzw. Testnormierung von Referenzwerten im DMT mit ausreichend grosen und reprasentativen Stichproben.

Der haufig diskutierte Theorie-Praxis-Graben ist eine Metapher, die aus einer sportwissenschaftlichen Perspektive die schwierige Kommunikation und fehlende Akzeptanz in der Sportpraxis beschreibt. Aus einer sportpraktischen Perspektive handelt es sich um einen Praxis-Theorie-Graben in der Sportwissenschaft, der jedoch mit denselben Schwierigkeiten konfrontiert ist. Der Anspruch einer anwendungsnahen Sportwissenschaft und damit das Uberwinden des Grabens aus beiden Richtungen bedingt die explizite Wertschatzung der jeweils anderen Expertise bzw. domainspezifischen Erfahrung und die Akzeptanz der eigenen Erfahrungsgrenzen in einem konstruktiven und zielfuhrenden Diskurs.

Background: Graft-versus-host disease (GVHD) is a dreaded complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Such inflammatory diseases are fostered by damage to the intestinal barrier after transplantation. Consequently, the integrity and regeneration of the intestinal barrier is a key factor in the prevention of GVHD. On one side the main driver for regeneration of damaged gut epithelium are intestinal stem cells (ISC), but on the other side these cells are themselves primary targets of donor-derived T cells. One known mechanism of T cell mediated damage to the stem cell compartment is through IFN-γ dependent ISC toxicity. Yet, little is known about how T cells are contributing to the regeneration of damaged tissue after allo-HSCT and GVHD. Methods: To address this, we used preclinical models for allo-HSCT and GVHD including transplantation of recipient mice with escalating doses of Wildtype or IFN-γ-deficient allogeneic T cells and in the presence or absence of the JAK-1/2 inhibitor ruxolitinib. Intestinal regeneration was assessed by RNA-seq, flow cytometry and a newly established ex vivo organoid recovery assay. GVHD outcome was assessed by clinical scoring, histology and survival. Additionally, we established an allogeneic co-culture system of murine or human intestinal organoids with CD4+ conventional T cells or T regs -/+ Ruxolitinib. Effects on organoid growth and cell death were assessed by size measurements and manual counting after passaging. Results: We here demonstrate that recipient mice with increasingly dense intestinal infiltration by allogeneic T cells not only developed more severe GVHD (Fig. 1A), but also showed augmented recovery potential early after allo-HSCT (Fig. 1B). This was associated with intestinal gene signatures related to epithelial regeneration and protection from GVHD. Utilizing ex vivo cultures of intestinal organoids generated from murine allo-HSCT recipients, we found that development of GVHD but also regenerative capacity of ISCs were dependent on interferon (IFN)-γ-producing T cells in the intestine (Fig. 2A-B). Mice with fulminant GVHD and enhanced organoid recovery showed accumulation of intestinal regulatory T cells (Tregs) (Fig. 2C). Ex vivo, T regs nurtured growth of intestinal organoids in an IFN-γ dependent manner (Fig. 2D-E). This effect was diminished in intestinal organoids lacking IFNγR signaling, but was independent of T reg intrinsic IFNγR signaling (Fig. 2E-F). Intriguingly, treatment of murine allo-HSCT recipients with the JAK-1/2 inhibitor ruxolitinib enhanced epithelial organoid regeneration and numbers of intestinal Tregs (Fig. 3A-B). Similarily, growth of human intestinal organoids co-cultured with allogeneic T cells could be augmented by ruxolitinib treatment (Fig. 3C). We thus propose that the level and differentiation of infiltrating intestinal T cells determines both ISC damage and epithelial regeneration during immune-mediated tissue injury, leading to a sensitive equilibrium that can be modulated by therapeutic intervention. We also provide evidence that ruxolitinib improves ISC regeneration via IFNγ-producing Treg cells. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Muehlbauer, T, Pabst, J, Granacher, U, and Büsch, D. Validity of the jump-and-reach test in subelite adolescent handball players. J Strength Cond Res 31(5): 1282-1289, 2017-The primary purpose of this study was to examine concurrent validity of the jump-and-reach (JaR) test using the Vertec system and a criterion device (i.e., Optojump system). In separate subanalyses, we investigated the influence of gym floor condition and athletes' sex on the validity of vertical jump height. Four hundred forty subelite adolescent female (n = 222, mean age: 14 ± 1 year, age range: 13-15 years) and male (n = 218, mean age: 15 ± 1 year, age range: 14-16 years) handball players performed the JaR test in gyms with region or point elastic floors. Maximal vertical jump height was simultaneously assessed using the Vertec and the Optojump systems. In general, significantly higher jump heights were obtained for the Vertec compared with the Optojump system (11.2 cm, Δ31%, Cohen's d = 2.58). The subanalyses revealed significantly larger jump heights for the Vertec compared with the Optojump system irrespective of gym floor condition and players' sex. The association between Optojump- and Vertec-derived vertical jump heights amounted to rP = 0.84, with a coefficient of determination (R) of 0.71. The subanalyses indicated significantly larger correlations in males (rP = 0.75, R = 0.56) than in females (rP = 0.63, R = 0.40). Yet, correlations were not significantly different between region (rP = 0.83, R = 0.69) as opposed to point elastic floor (rP = 0.87, R = 0.76). Our findings indicate that the 2 apparatuses cannot be used interchangeably. Consequently, gym floor and sex-specific regression equations were provided to estimate true (Optojump system) vertical jump height from Vertec-derived data.

Referees in sports games have a high level of responsibility as they have to make correct and appropriate decisions at any point during a match. Regarding referees’ decision-making (RDM) as a perceptual-cognitive process, evidence suggests that physical load might reduce cognitive performance and thus might reduce RDM performance as well. In consideration of increasing game dynamics, referees have to cope with high physical load, but they have to make correct and appropriate decisions further on. Here, we review the current state of research on the relationship between physical load and RDM. A scoping review was performed, in accordance with the PRISMA guidelines, using the following databases: Scopus, PubMed, Web of Science (all databases), SURF and SPONET (both with an English and German search). Only primary studies written in English or German that investigated the relationship between physical load and RDM in sports games were included. Eleven studies included in the review investigated six physical parameters and RDM: match period, velocity, blood lactate, running time, heart rate, distance covered. Most findings of the studies showed no relationship between physical load and RDM (n = 18). Thirteen findings suggest a negative relationship and three findings indicate a positive relationship between physical load and RDM. Results of the scoping review show contradictory evidence across and within investigated different physical parameters. As RDM consists of multi-factorial components, it is recommended to conduct systematic research programs – field as well as experimental studies – to resolve the missing control of potential confounding variables and to consider the difference of internal and external load.

Background Motor competence and physical fitness are important factors for promoting positive trajectories of health over time. In 2008, Stodden and colleagues developed a model that discussed the role of both factors in physical activity. Furthermore, the authors hypothesized that the relationship between motor competence and physical fitness is reciprocal and changes over time. Objective The aim of the present meta-analysis was to synthesize the evidence on the relationship between motor competence and components of physical fitness from early childhood to early adulthood and the potential influence of age. Methods Scientific databases Web of Science and PubMed were used for literatures search. German as well as English studies were included that assessed typically developing children. In accordance with the PRISMA guidelines, 93 studies between 2005 and June 2018 were screened in full. Nineteen studies comprising of 32 samples, 87 single data points from 15,984 participants aged 4.5 to 20.4 years (Mage = 11.44, SD = 4.77) were included in the analysis. ResultsA random effects model was conducted for the meta-regression with age as moderator variable. The relationship between motor competence and physical fitness was moderate to large (r = .43, p < .001) after controlling for multiple effects, including dependent samples and small sample sizes in the quantitative synthesis. Additionally, age was a small significant positive moderator of the effect size. Conclusions and implicationsThe findings provide support for a moderate to large positive relationship between motor competence and physical fitness that strengthens with increasing age. However, the results also indicate that there may be an overlap in content between motor competence and physical fitness assessments, which warrants further investigation. Further research is needed that assesses the similarities and differences also in terms of the construct structures.

There is little research investigating the maintenance of perceptual-cognitive expertise in general and even less comparing coaches of different ages. The aim of this study was to test for perceptual-cognitive differences between age groups, licence levels, and their interaction. This study investigated differences in skilled performance between young and middle-aged coaches of three different skill levels. Participants performed an accuracy-oriented pattern recall (mean distance in pixel) and a time-oriented flicker test (mean detection time in ms). There were some significant differences between age groups and between skill groups for both tests, but no interactions. For the pattern recall test, the effect sizes were larger for skill level differences, while for the flicker test effects were larger for ageing. These results suggest coaches are able to maintain accuracy skills better than reaction timed tasks. This is in line with findings on speeded performance in general populations, which show declines with age. Moreover, results also support findings on perceptual expertise in skills where accuracy was important.

Pediatric malignancies, in particular Ewing sarcoma (EwS), are characterized by low mutational load, low immunogenicity, and early metastasis. They recapitulate the embryonic immune tolerance setting and remain a challenge for established immunotherapies. These immunotherapies are not sufficient to target metastasis. Ideally, targeted therapies address gene products required for metastasis. We completed in vivo functional analyses for metastasis of 9/37 genes that we had shown to be overexpressed in EwS (Staege at al., Cancer Res 2004) and generated HLA class I restricted cytotoxic T cells against these gene products. All targets were involved in fetal development and 8/9 demonstrated functional relevance for metastasis. Allorepertoire-derived TCRs against 8/9 targets were cloned and sequenced; one target (DKK2) was nonimmunogenic. 7/8 TCRs were crossreactive, caused fratricide, or clonal TCR expansion failed (EZH2, STEAP1, PAPP-A, GPR64, ADRB3, LIPI, HOX-D1). In the tumor microenvironment we found an immunosuppressive (M0 and M2) transcriptomic signature and evidence for an immunosuppressive inflammation-associated activation of endogenous retroviral sequences. Among these most selectively expressed (n=9) and metastasis sustaining (n=8) targets, the BRICHOS chaperon domain containing antiangiogenetic bone protein chondromodulin-I (CHM1) was addressable by a non-crossreactive TCR. CHM1 is a direct downstream target of the oncogenic driver EWS-FLI1. We clinically assessed HLAA* 02:01/CHM1-specific TCR transgenic CD8+ T cells against EwS utilizing a TCR complementary determining region 3 (CDR3) recognition-sequence for the CHM1319 peptide with a Koff half-life of 113.2 ± 38.2 s. The CHM1319 motive was 130 times less homologous as compared to the 9mer ADRB3CHM1295, a crossreactive EwS target identified before. Four refractory HLA-A2+ EwS patients (pts) were treated with CHM1319-specific TCR-CDR3 transgenic T cells. Pt-derived cell lines (PDCL) were established in all cases. Pts received up to 107/kg TCR transgenic CD8+ T cells. All pts were treated with the same TCR-CDR3 recognition-sequence for CHM1. All PDCLs displayed persistent HLA-A2 expression. Transgenic T cells showed specific in vitro lysis of all PDCLs. Therapy was well tolerated and did not cause graft-versus-host disease (GvHD). Pts #1 #3 and #4 showed delayed progression, whereas pt #2, while having bone marrow (BM) involvement and accessible multifocal disease, showed partial metastatic regression associated with T-cell homing to involved lesions. In conclusion, CHM1319-TCR transgenic T cells may home to affected BM and may cause partial remission. CHM1-TCR transgenic T cells address a persistently expressed target required for metastasis, suggesting lack of immunoediting selection pressure. They proliferate in vivo without causing GvHD. This abstract is also being presented as Poster A07. Citation Format: Stefan Burdach, Guenther Richter, David Schirmer, Andreas Kirschner, Sebastian Schober, Valentina Evdokimova, Hendrik Gassmann, Elvira D’Ippolito, Maxim Barenboim, Dirk Busch, Poul Sorensen, Uwe Thiel. T-cell receptor (TCR)-based immunotherapy in pediatric malignancy: Addressing the challenge of early metastasis and low immunogenicity [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr PR05.

Purpose: To examine the effects of drop height on drop-jump (DJ) performance and on associations between DJ and horizontal-jump/sprint performances in adolescent athletes. Methods: Male (n = 119, 2.5 [0.6] y post-peak-height velocity) and female (n = 120, 2.5 [0.5] y post-peak-height velocity) adolescent handball players (national level) performed DJs in randomized order using 3 drop heights (20, 35, and 50 cm). DJ performance (jump height, reactive strength index [RSI]) was analyzed using the Optojump Next system. In addition, correlations were computed between DJ height and RSI with standing-long-jump and 20-m linear-sprint performances. Results: Statistical analyses revealed medium-size main effects of drop height for DJ height and RSI (P d ≤ 0.71). Post hoc tests indicated larger DJ heights from 20 to 35 and 35 to 50 cm (P ≤ .031, 0.33 ≤ d ≤ 0.71) and better RSI from 20- to 35-cm drop height (P d = 0.77). No significant difference was found for RSI between 35- and 50-cm drop height. Irrespective of drop height, associations of DJ height and RSI were small with 5-m-split time (−.27 ≤ r ≤ .05), medium with 10-m-split time (−.44 ≤ r ≤ .14), and medium to large with 20-m sprint time and standing-long-jump distance (−.57 ≤ r ≤ .22). Conclusions: The present findings indicate that, irrespective of sex, 35-cm drop heights are best suited to induce rapid and powerful DJ performance (ie, RSI) during reactive strength training in elite adolescent handball players. Moreover, training-related gains in DJ performance may at least partly translate to gains in horizontal jump and longer sprint distances (ie, ≥20-m) and/or vice versa in male and female elite adolescent athletes, irrespective of drop height.

Reactive strength exercises are characterized by muscle actions in the stretch-shortening cycle (SSC) which is why reactive strength training is a specific form of SSC training. During the SSC, the pre-activated muscle is lengthened in the braking or plyometric phase (i.e., eccentric phase) followed by an immediate muscle shortening in the push off or myometric phase (i.e., concentric phase). However, it is to be assumed that 95% of sport-related movements are conducted in the SSC. Reactive strength training represents an effective mode of exercise to improve in particular throwing and jumping performances. It contributes positively to improved agility, speed of action, and other performance indicators in handball. Furthermore, reactive strength training supports positively the prevention of sport-related injuries, e.g., knee and ankle injuries, and helps to regain pre-injury performance level in athletes. A systematic and progressive training approach is presented during all stages of long-term athlete development to induce adaptive changes following reactive strength training and to increase the likelihood of transferring a talented young player into an elite athlete. The specific training variables of reactive strength training, such as exercise selection, training frequency, exercise order, training load and repetitions, and training volume as well as the technical correctness and movement quality of the exercise, have to be systematically controlled and gradually adjusted according to the development of the athletes.

Sport games are characterized by their play structure. To date, the play structure of volleyball remains poorly understood. The aim of this study was to identify play structure variables that are appropriate for differentiating between top-level teams and second-level teams in elite international men’s volleyball.236 sets played by 14 teams during top international events were video recorded and analysed for variables related to action sequences (attack, counter-attack), attack tempo (fast, medium, slow), attack positions (1-6) and attack combinations (e.g., high passes on position 4 or 5). A discriminant analysis was conducted for the following dependent variables: (1) results (win vs. lose) and (2) team level (top-level teams vs. second-level teams).The best predictors for results and team levels are variables (effectivity of counter-attack, effectivity of medium and slow attack-tempo) related to complex 2 (action sequences of defending, setting and counter-attacking). In contrast, the impact of complex...

Empirische Beobachtungsergebnisse werden mit statistischen Verfahren ausgewertet, um Zusammenhange und Unterschiede zu prufen und sachgerecht interpretieren zu konnen. Die statistisch-methodologische Auswertungsstrategie entspricht einer formalen Sprache, die zu lernen ist, um sich mit anderen Forscher(inne)n verstandigen zu konnen, die aber, wie andere Gegenstandsgebiete auch, durch neue Erkenntnisse im Wandel begriffen ist und damit sich auch entsprechende Empfehlungen zur Verwendung optimaler statistischer Methoden im Laufe der Zeit wandeln. Dieser Gedanke wird in diesem kurzen Diskussionsbeitrag aufgegriffen, und es werden Empfehlungen zu funf zentralen Bereichen gegeben: a) Gerichtetheit der Hypothesen, b) Konfidenzintervalle, c) Effektgrosen, d) Intervall-Effektgrosen und e) praktische Bedeutsamkeit.

Für den aus 8 Items bestehenden Deutschen Motorik-Test 6-18 ( Bös et al., 2009 ) konnte bislang weder ein eindimensionales noch zweidimensionales (Koordination/Kondition) Strukturmodell bestätigt werden. Anhand probabilistischer (Mixed-Rasch-Modell) und klassischer (konfirmatorische Faktorenanalyse) Testmodelle wird geprüft, ob von Bös et al. (2009) empfohlene Normkategorien oder eine alternative Kategorisierung empirische Validität besitzen. Im Kreuzvalidierungsdesign werden für 9 – 10-Jährige mittels zweier Stichproben (N 1 = 1495, N 2 = 1357; 49,2 % weiblich) Analysen mit den Norm-Quintilen und Z-normierten Norm-Leistungsklassen sowie Standardnoten nach T-Transformation der empirischen Daten (eT-Kategorien) durchgeführt. Die Konstruktvalidität bezüglich der beiden publizierten Normkategorisierungen kann nicht nachgewiesen werden. Demgegenüber ergibt die Analyse der eT-Kategorisierung eine Ein-Klassen-Lösung des Mixed-Rasch-Modells, wobei theoriekonform „Rumpfbeuge“ und aufgrund lokaler Modellverletzungen „Balancieren rückwärts“ auszuschließen sind. Die faktorielle Validität dieses eindimensionalen Modells wird bestätigt. Für 9 – 10-Jährige kann demnach Homogenität bezüglich eines eindimensionalen Motorik-Index (mit sechs Items) angenommen werden. Dieser Motorik- resp. Fitness-Index kann aus den sechs homogenen Items gebildet werden und ist für sportmotorische Testungen valide interpretierbar.

This chapter provides a rationale and exemplification on how statistics can be utilized in talent identification with the aim to substantiate practitioners' and researchers' decision making. With the aim to promote adoption of statistical approaches as part of evidence-based practice in talent identification and development, the chapter highlights how statistics can potentially support talent identification and development decision-making. Proficiency levels in sport-specific movement or performance parameters represent key common criteria from which practitioners and researchers decide whether youth athletes are classified as talents. To accurately determine identification and selection decisions, qualitative and/or quantitative criteria are often utilized. The approach to use confidence intervals (CIs) for the evaluation of between-group differences can be translated to two equally and often reported questions in talent research. The first refers to performance changes over time in the group of talent and/or performance potential. The second implies individual and not group-based performance changes.

Background aims. Reactivation of cytomegalovirus (CMV) after hematopoietic stem cell transplantation remains a major cause of morbidity despite improved antiviral drug therapies. Selective restoration of CMV immunity by adoptive transfer of CMV-specific T cells is the only alternative approach that has been shown to be effective and non-toxic. We describe the results of clinical-scale isolations of CMV-specific donor lymphocytes with the use of a major histocompatibility (MHC) class I peptide streptamer-based isolation method that yields minimally manipulated cytotoxic T cells of high purity. Methods. Enrichment of CMV-specific cytotoxic T lymphocytes (CTLs) was performed by labeling 1 � 10 10 leukocytes from a nonmobilized mononuclear cell (MNC) apheresis with MHC class I streptamers and magnetic beads. Thereafter, positively labeled CMV-specific CTLs were isolated through the use of CliniMACS (magnetic-activated cell sorting), and MHC streptamers were released through the use of d-biotin. The purity of enriched CMV-specific CTLs was determined on the basis of MHC streptamer staining and fluorescence-activated cell sorting. Results. A total of 22 processes were performed with the use of five different MHC class I streptamers. The median frequency of CMV-specific CTLs in the starting apheresis product was 0.41% among CD3þ T cells. The isolation process yielded a total of 7.77 � 10 6 CMV-specific CTLs, with a median purity of 90.2%. Selection reagents were effectively removed from the final cell product; the CMV-specific CTLs displayed excellent viability and cytotoxicity and were stable for at least 72 h at 4 � C after MNC collection. Conclusions. Clinical-scale isolation of “minimally manipulated” CMV-specific donor CTLs through the use of MHC class I streptamers is feasible and yields functional CTLs at clinically relevant dosages.