TY - JOUR A1 - Kahlert, Daniela A1 - Brand, Ralf T1 - Comparing self-report and accelerometry data a contribution to the validation of the MoMo-Physical activity questionnaire for children and adolescents JF - Deutsche Zeitschrift für Sportmedizin : offizielles Organ der Deutschen Gesellschaft für Sportmedizin und Prävention (Deutscher Sportärztebund) e.V. (DGSP) und Weiterbildungsorgan der Österreichischen Gesellschaft für Sportmedizin und Prävention N2 - According to the results of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) published in 2009, only 5% to 8% of the 15-17-year-old adolescents reach the current recommendations on health-enhancing physical activity This result (besides others in the survey) rests on data measured with the 25-item physical activity questionnaire for children and adolescents (MoMo-AFB). The present study compares two different methods of assessing physical activity with the purpose of testing the validity of the MoMo-AFB self-report. First, we measured the physical activity status of 73 15 to 18-year-old pupils (32 boys and 41 girls) over seven days via objective accelerometry (ActiGraph GT1M), then the pupils completed the MoMo-AFB for the same (previous) period. Results show that using the MoMo-AFB leads to higher levels of self-reported physical activity than measuring it with accelerometers. Furthermore, only the MoMo-AFB subscale MVPA (moderate-to-vigorous physical activity), that uses two single items to decide whether the health-enhancing physical activity recommendation is reached or failed, corresponds statistically significantly with the accelerometry data. For all other subscales (e.g. school- or leisure time activity), we found no agreement. Further research, first of all on the measurement quality of the MoMo-AFB but also on the physical (in)activity status of children and adolescents, is needed. KW - Physical activity KW - means of measurement KW - physical activity questionnaires KW - accelerometry KW - adolescents Y1 - 2011 SN - 0344-5925 VL - 62 IS - 2 SP - 36 EP - + PB - WWF-Verl.-Ges. CY - Greven ER - TY - JOUR A1 - Müller, Juliane A1 - Müller, Steffen A1 - Stoll, Josefine A1 - Baur, Heiner A1 - Mayer, Frank T1 - Trunk extensor and flexor strength capacity in healthy young elite athletes aged 11-15 Years JF - Journal of strength and conditioning research : the research journal of the NSCA N2 - Mueller, J, Mueller, S, Stoll, J, Baur, H, and Mayer, F. Trunk extensor and flexor strength capacity in healthy young elite athletes aged 11-15 years. J Strength Cond Res 28(5): 1328-1334, 2014-Differences in trunk strength capacity because of gender and sports are well documented in adults. In contrast, data concerning young athletes are sparse. The purpose of this study was to assess the maximum trunk strength of adolescent athletes and to investigate differences between genders and age groups. A total of 520 young athletes were recruited. Finally, 377 (n = 233/144 M/F; 13 +/- 1 years; 1.62 +/- 0.11 m height; 51 +/- 12 kg mass; training: 4.5 +/- 2.6 years; training sessions/week: 4.3 +/- 3.0; various sports) young athletes were included in the final data analysis. Furthermore, 5 age groups were differentiated (age groups: 11, 12, 13, 14, and 15 years; n = 90, 150, 42, 43, and 52, respectively). Maximum strength of trunk flexors (Flex) and extensors (Ext) was assessed in all subjects during isokinetic concentric measurements (60 degrees center dot s(-1); 5 repetitions; range of motion: 55 degrees). Maximum strength was characterized by absolute peak torque (Flex(abs), Ext(abs); N center dot m), peak torque normalized to body weight (Flex(norm), Ext(norm); N center dot m center dot kg(-1) BW), and Flex(abs)/Ext(abs) ratio (RKquot). Descriptive data analysis (mean +/- SD) was completed, followed by analysis of variance (alpha = 0.05; post hoc test [Tukey-Kramer]). Mean maximum strength for all athletes was 97 +/- 34 N center dot m in Flex(abs) and 140 +/- 50 N center dot m in Ext(abs) (Flex(norm) = 1.9 +/- 0.3 N center dot m center dot kg(-1) BW, Ext(norm) = 2.8 +/- 0.6 N center dot m center dot kg(-1) BW). Males showed statistically significant higher absolute and normalized values compared with females (p < 0.001). Flex(abs) and Ext(abs) rose with increasing age almost 2-fold for males and females (Flex(abs), Ext(abs): p < 0.001). Flex(norm) and Ext(norm) increased with age for males (p < 0.001), however, not for females (Flex(norm): p = 0.26; Ext(norm): p = 0.20). RKquot (mean +/- SD: 0.71 +/- 0.16) did not reveal any differences regarding age (p = 0.87) or gender (p = 0.43). In adolescent athletes, maximum trunk strength must be discussed in a gender- and age-specific context. The Flex(abs)/Ext(abs) ratio revealed extensor dominance, which seems to be independent of age and gender. The values assessed may serve as a basis to evaluate and discuss trunk strength in athletes. KW - core KW - adolescents KW - isokinetic KW - strength performance Y1 - 2014 U6 - https://doi.org/10.1519/JSC.0000000000000280 SN - 1064-8011 SN - 1533-4287 VL - 28 IS - 5 SP - 1328 EP - 1334 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Müller, Steffen A1 - Carlsohn, Anja A1 - Müller, Juliane A1 - Baur, Heiner A1 - Mayer, Frank T1 - Influence of Obesity on Foot Loading Characteristics in Gait for Children Aged 1 to 12 Years JF - PLoS one N2 - Background Overweight and obesity are increasing health problems that are not restricted to adults only. Childhood obesity is associated with metabolic, psychological and musculoskeletal comorbidities. However, knowledge about the effect of obesity on the foot function across maturation is lacking. Decreased foot function with disproportional loading characteristics is expected for obese children. The aim of this study was to examine foot loading characteristics during gait of normal-weight, overweight and obese children aged 1-12 years. Methods A total of 10382 children aged one to twelve years were enrolled in the study. Finally, 7575 children (m/f: n = 3630/3945; 7.0 +/- 2.9yr; 1.23 +/- 0.19m; 26.6 +/- 10.6kg; BMI: 17.1 +/- 2.4kg/m(2)) were included for (complete case) data analysis. Children were categorized to normalweight (>= 3rd and <90th percentile; n = 6458), overweight (>= 90rd and <97th percentile; n = 746) or obese (>97th percentile; n = 371) according to the German reference system that is based on age and gender-specific body mass indices (BMI). Plantar pressure measurements were assessed during gait on an instrumented walkway. Contact area, arch index (AI), peak pressure (PP) and force time integral (FTI) were calculated for the total, fore-, mid-and hindfoot. Data was analyzed descriptively (mean +/- SD) followed by ANOVA/Welch-test (according to homogeneity of variances: yes/no) for group differences according to BMI categorization (normal-weight, overweight, obesity) and for each age group 1 to 12yrs (post-hoc Tukey Kramer/Dunnett's C; alpha = 0.05). Results Mean walking velocity was 0.95 +/- 0.25 m/s with no differences between normal-weight, overweight or obese children (p = 0.0841). Results show higher foot contact area, arch index, peak pressure and force time integral in overweight and obese children (p< 0.001). Obese children showed the 1.48-fold (1 year-old) to 3.49-fold (10 year-old) midfoot loading (FTI) compared to normal-weight. Conclusion Additional body mass leads to higher overall load, with disproportional impact on the midfoot area and longitudinal foot arch showing characteristic foot loading patterns. Already the feet of one and two year old children are significantly affected. Childhood overweight and obesity is not compensated by the musculoskeletal system. To avoid excessive foot loading with potential risk of discomfort or pain in childhood, prevention strategies should be developed and validated for children with a high body mass index and functional changes in the midfoot area. The presented plantar pressure values could additionally serve as reference data to identify suspicious foot loading patterns in children. KW - plantar pressure distribution KW - body-mass index KW - prepubescent children KW - overweight children KW - childhood obesity KW - walking KW - speed KW - forces KW - adolescents KW - prevalence Y1 - 2016 U6 - https://doi.org/10.1371/journal.pone.0149924 SN - 1932-6203 VL - 11 IS - 2 PB - Public Library of Science CY - Lawrence, Kan. ER - TY - JOUR A1 - Hammami, Raouf A1 - Granacher, Urs A1 - Makhlouf, Issam A1 - Behm, David George A1 - Chaouachi, Anis T1 - SEQUENCING EFFECTS OF BALANCE AND PLYOMETRIC TRAINING ON PHYSICAL PERFORMANCE IN YOUTH SOCCER ATHLETES JF - Journal of strength and conditioning research : the research journal of the NSCA N2 - Balance training may have a preconditioning effect on subsequent power training with youth. There are no studies examining whether the sequencing of balance and plyometric training has additional training benefits. The objective was to examine the effect of sequencing balance and plyometric training on the performance of 12- to 13-year-old athletes. Twenty-four young elite soccer players trained twice per week for 8 weeks either with an initial 4 weeks of balance training followed by 4 weeks of plyometric training (BPT) or 4 weeks of plyometric training proceeded by 4 weeks of balance training (PBT). Testing was conducted pre- and posttraining and included medicine ball throw; horizontal and vertical jumps; reactive strength; leg stiffness; agility; 10-, 20-, and 30-m sprints; Standing Stork balance test; and Y-Balance test. Results indicated that BPT provided significantly greater improvements with reactive strength index, absolute and relative leg stiffness, triple hop test, and a trend for the Y-Balance test (p = 0.054) compared with PBT. Although all other measures had similar changes for both groups, the average relative improvement for the BPT was 22.4% (d = 1.5) vs. 15.0% (d = 1.1) for the PBT. BPT effect sizes were greater with 8 of 13 measures. In conclusion, although either sequence of BPT or PBT improved jumping, hopping, sprint acceleration, and Standing Stork and Y-Balance, BPT initiated greater training improvements in reactive strength index, absolute and relative leg stiffness, triple hop test, and the Y-Balance test. BPT may provide either similar or superior performance enhancements compared with PBT. KW - children KW - adolescents KW - power KW - jumps KW - sprints Y1 - 2016 U6 - https://doi.org/10.1519/JSC.0000000000001425 SN - 1064-8011 SN - 1533-4287 VL - 30 SP - 3278 EP - 3289 PB - Elsevier CY - Philadelphia ER - TY - JOUR A1 - Weber, Stephanie A1 - Puta, Christian A1 - Lesinski, Melanie A1 - Gabriel, Brunhild A1 - Steidten, Thomas A1 - Bär, Karl-Jürgen A1 - Herbsleb, Marco A1 - Granacher, Urs A1 - Gabriel, Holger H. W. T1 - Symptoms of anxiety and depression in young athletes using the hospital anxiety and depression scale JF - Frontiers in physiology N2 - Elite young athletes have to cope with multiple psychological demands such as training volume, mental and physical fatigue, spatial separation of family and friends or time management problems may lead to reduced mental and physical recovery. While normative data regarding symptoms of anxiety and depression for the general population is available (Hinz and Brahler, 2011), hardly any information exists for adolescents in general and young athletes in particular. Therefore, the aim of this study was to assess overall symptoms of anxiety and depression in young athletes as well as possible sex differences. The survey was carried out within the scope of the study "Resistance Training in Young Athletes" (KINGS-Study). Between August 2015 and September 2016, 326 young athletes aged (mean +/- SD) 14.3 +/- 1.6 years completed the Hospital Anxiety and Depression Scale (HAD Scale). Regarding the analysis of age on the anxiety and depression subscales, age groups were classified as follows: late childhood (12-14 years) and late adolescence (15-18 years). The participating young athletes were recruited from Olympic weight lifting, handball, judo, track and field athletics, boxing, soccer, gymnastics, ice speed skating, volleyball, and rowing. Anxiety and depression scores were (mean +/- SD) 4.3 +/- 3.0 and 2.8 +/- 2.9, respectively. In the subscale anxiety, 22 cases (6.7%) showed subclinical scores and 11 cases (3.4%) showed clinical relevant score values. When analyzing the depression subscale, 31 cases (9.5%) showed subclinical score values and 12 cases (3.7%) showed clinically important values. No significant differences were found between male and female athletes (p >= 0.05). No statistically significant differences in the HADS scores were found between male athletes of late childhood and late adolescents (p >= 0.05). To the best of our knowledge, this is the first report describing questionnaire based indicators of symptoms of anxiety and depression in young athletes. Our data implies the need for sports medical as well as sports psychiatric support for young athletes. In addition, our results demonstrated that the chronological classification concerning age did not influence HAD Scale outcomes. Future research should focus on sports medical and sports psychiatric interventional approaches with the goal to prevent anxiety and depression as well as teaching coping strategies to young athletes. KW - youth athletes KW - anxiety KW - depression KW - gender differences KW - late childhood KW - adolescents Y1 - 2018 U6 - https://doi.org/10.3389/fphys.2018.00182 SN - 1664-042X VL - 9 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Chaouachi, Anis A1 - Ben Othman, Aymen A1 - Makhlouf, Issam A1 - Young, James D. A1 - Granacher, Urs A1 - Behm, David George T1 - Global Training Effects of Trained and Untrained Muscles With Youth Can be Maintained During 4 Weeks of Detraining JF - Journal of strength and conditioning research : the research journal of the NSCA N2 - Global (whole-body) effects of resistance training (i.e., cross-education) may be pervasive with children. Detraining induces less substantial deficits with children than adults. It was the objective of this study to investigate the global responses to 4 weeks of detraining after 8 weeks of unilateral leg press (LP) training in 10-13-year-old, pre-peak-height-velocity stage boys. Subjects were randomly separated into 2 unilateral resistance training groups (high load/low repetitions [HL-LR] and low load/high repetitions [LL-HR], and control group). Assessments at pre-training, post-training, and detraining included dominant and nondominant limbs, unilateral, 1 repetition maximum (1RM) and 60% 1RM LP, knee extension, knee flexion, elbow flexion, and handgrip maximal voluntary isometric contraction (MVIC), and countermovement jump (CMJ). All measures significantly increased from pre-test to detraining for both training programs, except for elbow flexion MVIC with increases only with HL-LR. All measures except CMJ and handgrip MVIC significantly decreased from post-test to detraining, except for elbow flexion MVIC with decreases only with HL-LR. The dominant trained limb experienced significantly greater LP improvements (pre- to detraining) and decrements (post- to detraining) with LP 1RM and 60% 1RM LP. In conclusion, youth HL-LR and LL-HR global training effects of trained and untrained limbs demonstrate similar benefits (pre- to detraining) and decrements (post- to detraining) with detraining. The findings emphasize that training any muscle group in a child can have positive global implications for improved strength and power that can persist over baseline measures for at least a month. KW - adolescents KW - strength training KW - deconditioning KW - cross-education KW - children Y1 - 2019 U6 - https://doi.org/10.1519/JSC.0000000000002606 SN - 1064-8011 SN - 1533-4287 VL - 33 IS - 10 SP - 2788 EP - 2800 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Chaabene, Helmi A1 - Lesinski, Melanie A1 - Behm, David George A1 - Granacher, Urs T1 - Performance- and healthrelated benefits of youth resistance training T1 - Leistungs- und gesundheitsbezogene Wirkungen von Krafttraining mit Heranwachsenden JF - Sports Orthopaedics and Traumatology N2 - Performance- and healthrelated benefits of yoThere is ample evidence that youth resistance training (RT) is safe, joyful, and effective for different markers of performance (e.g., muscle strength, power, linear sprint speed) and health (e.g., injury prevention). Accordingly, the first aim of this narrative review is to present and discuss the relevance of muscle strength for youth physical development. The second purpose is to report evidence on the effectiveness of RT on muscular fitness (muscle strength, power, muscle endurance), on movement skill performance and injury prevention in youth. There is evidence that RT is effective in enhancing measures of muscle fitness in children and adolescents, irrespective of sex. Additionally, numerous studies indicate that RT has positive effects on fundamental movement skills (e.g., jumping, running, throwing) in youth regardless of age, maturity, training status, and sex. Further, irrespective of age, sex, and training status, regular exposure to RT (e.g., plyometric training) decreases the risk of sustaining injuries in youth. This implies that RT should be a meaningful element of youths’ exercise programming. This has been acknowledged by global (e.g., World Health Organization) and national (e.g., National Strength and Conditioning Association) health- and performance-related organizations which is why they recommended to perform RT as an integral part of weekly exercise programs to promote muscular strength, fundamental movement skills, and to resist injuries in youth.uth resistance training N2 - Die aktuelle Literatur zum Krafttraining mit Kindern und Jugendlichen zeigt eindrücklich, dass ein altersgerechtes und fachlich angeleitetes Krafttraining eine sichere, freudvolle und effektive Maßnahme für die Leistungsentwicklung (z. B. Muskelkraft, Schnellkraft, Sprintgeschwindigkeit) und Gesundheitserhaltung (z. B. Verletzungsprävention) von Heranwachsenden darstellt. Einerseits ist es das Ziel dieses narrativen Übersichtsartikels, die Relevanz der Muskelkraft für die körperliche Entwicklung von Heranwachsenden zu diskutieren. Andererseits sollen aktuelle Befunde zur Effektivität von Krafttraining auf die muskuläre Fitness (Maximal-/Schnellkraft, Kraftausdauer), elementare Bewegungsfertigkeiten (z.B. Springen, Rennen, Werfen) sowie die Verletzungsprävention bei Kindern und Jugendlichen beschrieben werden. Die aktuelle Literatur belegt, dass Krafttraining die Muskelkraft, die Schnellkraft und die Kraftausdauer von Kindern und Jugendlichen unabhängig vom Geschlecht verbessern kann. Weiterhin zeigen Studien, dass trainingsbedingte Verbesserungen der muskulären Fitness auf elementare Bewegungsfertigkeiten transferieren. Diese Wirkungen sind unabhängig vom Alter, der biologischen Reife, dem Trainingsstatus und dem Geschlecht der Trainierenden. Zudem verringert regelmäßiges Krafttraining das Verletzungsrisiko der Heranwachsenden unabhängig von Alter, Geschlecht und Trainingsstatus. Aufgrund dieses breiten Wirkungsspektrums sollte Krafttraining ein elementarer Bestandteil des Trainings von Heranwachsenden darstellen. Nationale (National Strength and Conditioning Association) sowie internationale (Weltgesundheitsorganisation) gesundheits- und leistungsorientierte Standesgesellschaften haben die positiven Wirkungen von Krafttraining erkannt und in ihre Bewegungsempfehlungen für Kinder und Jugendliche übernommen. KW - muscle strength KW - muscle power KW - strength training KW - children KW - adolescents KW - Maximalkraft KW - Schnellkraft KW - Widerstandstraining KW - Kinder KW - Jugendliche Y1 - 2020 VL - 36 IS - 3 PB - Elsevier CY - Amsterdam ER -