Early sports specialization in Japanese young soccer players and related factors

• Yasuharu Nagano ,

  Roles Conceptualization, Data curation, Formal analysis, Funding acquisition, Investigation, Methodology, Validation, Writing – original draft

  * E-mail: nagano.yasuharu@jwcpe.ac.jp

  Affiliation Department of Sports and Health Science, Japan Women’s College of Physical Education, Setagaya, Tokyo, Japan

  https://orcid.org/0000-0001-6964-2245

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• Shogo Sasaki,

  Roles Data curation, Formal analysis, Funding acquisition, Writing – review & editing

  Affiliation Department of Competitive Sports, School of Physical Education, Tokai University, Hiratsuka, Kanagawa, Japan

  https://orcid.org/0000-0002-0424-2416

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• Ayako Higashihara,

  Roles Methodology, Validation, Writing – review & editing

  Affiliation Institute of Physical Education, Keio University, Yokohama, Kanagawa, Japan

  https://orcid.org/0000-0002-8634-0959

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• Takashi Oyama

  Roles Conceptualization, Data curation, Writing – review & editing

  Affiliation Faculty of Economics, Teikyo University, Hachioji, Tokyo, Japan

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