{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,7]],"date-time":"2026-05-07T00:30:08Z","timestamp":1778113808818,"version":"3.51.4"},"reference-count":82,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2021,3,30]],"date-time":"2021-03-30T00:00:00Z","timestamp":1617062400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Portuguese Institute of Sports and Youth (IPDJ)","award":["CP\/594\/DD\/2018"],"award-info":[{"award-number":["CP\/594\/DD\/2018"]}]},{"name":"Portuguese Olympic Committee (COP)","award":["--"],"award-info":[{"award-number":["--"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJERPH"],"abstract":"<jats:p>Youth soccer performance is multifaceted, includes physical growth, biological maturation, and physical fitness, and is linked to the sporting environment to which the players are exposed. We aim to describe age-related associations in body physique, body composition, physical performance technical and tactical skills, psychological and club characteristics of male soccer players aged 12 to 14 years. A total of 157 male soccer players clustered into three age-cohorts (12, 13 and 14 years) were recruited from six soccer clubs. Anthropometric, body composition and body physique, biological maturation, physical performance, skill\/game proficiency data, psychological characteristics, and clubs\u2019 characteristics were collected. Group means were compared using analysis of variance and covariance. Fourteen years old players were significantly taller, heavier, leaner, faster, stronger, and technically more skilled than their younger peers (p &lt; 0.05). Differences in physical performance and technical skills (p &lt; 0.05) were found between age groups when adjusting for confounders of soccer training and biological maturation. No significant differences (p &gt; 0.05) between age groups were found in psychological domains. Our findings suggest that age, biological maturation, and training volume are key factors influencing young soccer players\u2019 performance and development. Further, clubs\u2019 conditions provide players with ample resources for their success in training and competition.<\/jats:p>","DOI":"10.3390\/ijerph18073560","type":"journal-article","created":{"date-parts":[[2021,3,30]],"date-time":"2021-03-30T03:29:45Z","timestamp":1617074985000},"page":"3560","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Body Physique, Body Composition, Physical Performance, Technical and Tactical Skills, Psychological Development, and Club Characteristics of Young Male Portuguese Soccer Players: The INEX Study"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7500-9155","authenticated-orcid":false,"given":"Maryam","family":"Abarghoueinejad","sequence":"first","affiliation":[{"name":"Centre of Research, Education, Innovation, and Intervention in Sport (CIFI2D), Faculty of Sport, University of Porto, 4200-450 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2701-2303","authenticated-orcid":false,"given":"Daniel","family":"Barreira","sequence":"additional","affiliation":[{"name":"Centre of Research, Education, Innovation, and Intervention in Sport (CIFI2D), Faculty of Sport, University of Porto, 4200-450 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0418-0056","authenticated-orcid":false,"given":"Cl\u00e1udia","family":"Dias","sequence":"additional","affiliation":[{"name":"Centre of Research, Education, Innovation, and Intervention in Sport (CIFI2D), Faculty of Sport, University of Porto, 4200-450 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5344-9344","authenticated-orcid":false,"given":"Eduardo","family":"Guimar\u00e3es","sequence":"additional","affiliation":[{"name":"Centre of Research, Education, Innovation, and Intervention in Sport (CIFI2D), Faculty of Sport, University of Porto, 4200-450 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0430-0556","authenticated-orcid":false,"given":"Adam D. G.","family":"Baxter-Jones","sequence":"additional","affiliation":[{"name":"College of Kinesiology, University of Saskatchewan, Saskatoon, SK S7N 5B2, Canada"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3273-0046","authenticated-orcid":false,"given":"Jos\u00e9","family":"Maia","sequence":"additional","affiliation":[{"name":"Centre of Research, Education, Innovation, and Intervention in Sport (CIFI2D), Faculty of Sport, University of Porto, 4200-450 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2021,3,30]]},"reference":[{"key":"ref_1","unstructured":"Tanner, J.M. (1962). 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