@article{MoranPaxtonJonesetal.2020,
  author    = {Moran, Jason and Paxton, Kevin and Jones, Ben and Granacher, Urs and Sandercock, Gavin Rh and Hope, Edward and Ramirez-Campillo, Rodrigo},
  title     = {Variable long-term developmental trajectories of short sprint speed and jumping height in English Premier League academy soccer players: an applied case study},
  series = {Journal of sports sciences},
  volume    = {38},
  journal   = {Journal of sports sciences},
  number    = {22},
  publisher = {Routledge, Taylor \& Francis Group},
  address   = {London},
  issn      = {0264-0414},
  doi       = {10.1080/02640414.2020.1792689},
  pages     = {2525 -- 2531},
  year      = {2020},
  abstract  = {Growth and maturation affect long term physical performance, making the appraisal of athletic ability difficult. We sought to longitudinally track youth soccer players to assess the developmental trajectory of athletic performance over a 6-year period in an English Premier League academy. Age-specific z-scores were calculated for sprint and jump performance from a sample of male youth soccer players (n = 140). A case study approach was used to analyse the longitudinal curves of the six players with the longest tenure. The trajectories of the sprint times of players 1 and 3 were characterised by a marked difference in respective performance levels up until peak height velocity (PHV) when player 1 achieved a substantial increase in sprint speed and player 3 experienced a large decrease. Player 5 was consistently a better performer than player 2 until PHV when the sprint and jump performance of the former markedly decreased and he was overtaken by the latter. Fluctuations in players' physical performance can occur quickly and in drastic fashion. Coaches must be aware that suppressed, or inflated, performance could be temporary and selection and deselection decisions should not be made based on information gathered over a short time period.},
  language  = {en}
}
@misc{LesinskiSchmelcherHerzetal.2020,
  author    = {Lesinski, Melanie and Schmelcher, Alina and Herz, Michael and Puta, Christian and Gabriel, Holger and Arampatzis, Adamantios and Laube, Gunnar and B{\"u}sch, Dirk and Granacher, Urs},
  title     = {Maturation-, age-, and sex-specific anthropometric and physical fitness percentiles of German elite young athletes},
  series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe},
  number    = {662},
  issn      = {1866-8364},
  doi       = {10.25932/publishup-48026},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-480268},
  pages     = {21},
  year      = {2020},
  abstract  = {The aim of this study was to establish maturation-, age-, and sex-specific anthropometric and physical fitness percentile reference values of young elite athletes from various sports. Anthropometric (i.e., standing and sitting body height, body mass, body mass index) and physical fitness (i.e., countermovement jump, drop jump, change-of-direction speed [i.e., T-test], trunk muscle endurance [i.e., ventral Bourban test], dynamic lower limbs balance [i.e., Y-balance test], hand grip strength) of 703 male and female elite young athletes aged 8-18 years were collected to aggregate reference values according to maturation, age, and sex. Findings indicate that body height and mass were significantly higher (p<0.001; 0.95≤d≤1.74) in more compared to less mature young athletes as well as with increasing chronological age (p<0.05; 0.66≤d≤3.13). Furthermore, male young athletes were significantly taller and heavier compared to their female counterparts (p<0.001; 0.34≤d≤0.50). In terms of physical fitness, post-pubertal athletes showed better countermovement jump, drop jump, change-of-direction, and handgrip strength performances (p<0.001; 1.57≤d≤8.72) compared to pubertal athletes. Further, countermovement jump, drop jump, change-of-direction, and handgrip strength performances increased with increasing chronological age (p<0.05; 0.29≤d≤4.13). In addition, male athletes outperformed their female counterpart in the countermovement jump, drop jump, change-of-direction, and handgrip strength (p<0.05; 0.17≤d≤0.76). Significant age by sex interactions indicate that sex-specific differences were even more pronounced with increasing age. Conclusively, body height, body mass, and physical fitness increased with increasing maturational status and chronological age. Sex-specific differences appear to be larger as youth grow older. Practitioners can use the percentile values as approximate benchmarks for talent identification and development.},
  language  = {en}
}
@article{LesinskiSchmelcherHerzetal.2020,
  author    = {Lesinski, Melanie and Schmelcher, Alina and Herz, Michael and Puta, Christian and Gabriel, Holger and Arampatzis, Adamantios and Laube, Gunnar and B{\"u}sch, Dirk and Granacher, Urs},
  title     = {Maturation-, age-, and sex-specific anthropometric and physical fitness percentiles of German elite young athletes},
  series = {Plos One},
  volume    = {15},
  journal   = {Plos One},
  number    = {8},
  publisher = {Plos One},
  address   = {San Francisco, California},
  issn      = {1932-6203},
  doi       = {10.1371/journal.pone.0237423},
  pages     = {19},
  year      = {2020},
  abstract  = {The aim of this study was to establish maturation-, age-, and sex-specific anthropometric and physical fitness percentile reference values of young elite athletes from various sports. Anthropometric (i.e., standing and sitting body height, body mass, body mass index) and physical fitness (i.e., countermovement jump, drop jump, change-of-direction speed [i.e., T-test], trunk muscle endurance [i.e., ventral Bourban test], dynamic lower limbs balance [i.e., Y-balance test], hand grip strength) of 703 male and female elite young athletes aged 8-18 years were collected to aggregate reference values according to maturation, age, and sex. Findings indicate that body height and mass were significantly higher (p<0.001; 0.95≤d≤1.74) in more compared to less mature young athletes as well as with increasing chronological age (p<0.05; 0.66≤d≤3.13). Furthermore, male young athletes were significantly taller and heavier compared to their female counterparts (p<0.001; 0.34≤d≤0.50). In terms of physical fitness, post-pubertal athletes showed better countermovement jump, drop jump, change-of-direction, and handgrip strength performances (p<0.001; 1.57≤d≤8.72) compared to pubertal athletes. Further, countermovement jump, drop jump, change-of-direction, and handgrip strength performances increased with increasing chronological age (p<0.05; 0.29≤d≤4.13). In addition, male athletes outperformed their female counterpart in the countermovement jump, drop jump, change-of-direction, and handgrip strength (p<0.05; 0.17≤d≤0.76). Significant age by sex interactions indicate that sex-specific differences were even more pronounced with increasing age. Conclusively, body height, body mass, and physical fitness increased with increasing maturational status and chronological age. Sex-specific differences appear to be larger as youth grow older. Practitioners can use the percentile values as approximate benchmarks for talent identification and development.},
  language  = {en}
}
@article{VockPenkKoeller2014,
  author    = {Vock, Miriam and Penk, Christiane and Koeller, Olaf},
  title     = {Who skips a grade? Findings concerning grade acceleration in German schools},
  series = {Psychologie in Erziehung und Unterricht : Zeitschrift f{\"u}r Forschung und Praxis},
  volume    = {61},
  journal   = {Psychologie in Erziehung und Unterricht : Zeitschrift f{\"u}r Forschung und Praxis},
  number    = {3},
  publisher = {Reinhardt},
  address   = {M{\"u}nchen},
  issn      = {0342-183X},
  doi       = {10.2378/peu2013.art22d},
  pages     = {153 -- 164},
  year      = {2014},
  abstract  = {This study examines how often and in which form students use the option of gradeskipping in Germany and what characterizes those students. The database was derived from a sample of N = 4,103 students (grades 8-10), who were tested within the standardisation process of the national educational standards in mathematics. For these students data existed on their mathematical competence (educational standard items) and intelligence (subtests word analogies and figural analogies of the KFT 4-12 + R). Furthermore, we identified n = 33 (0,8\%) students by questionnaire, who had already skipped one grade. Those accelerated students are predominantly boys, had skipped the grade during their first years at school and performed only slightly above-average on two cognitive ability scales. At the time the survey was conducted, 39\% did not attend a Gymnasium and 34 \% had to repeat one grade after having been accelerated. While they report average grades in relation to their peers, their mathematical competence is well above average.},
  language  = {de}
}