Seasonal changes in physical fitness and body composition and their associations with external match load in elite youth football players
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Purpose: To compare seasonal changes in body composition and physical fitness and examine their associations with external match load in elite youth football players. Methods: Twenty-nine players from the U18 (n = 14) and U21 (n = 15) squads were assessed during two competitive periods (First and Second Phase). Body composition included muscle mass (%MM), fat mass (%FM), and the sum of 6 skinfolds (6skf). Physical fitness assessments comprised countermovement jump (CMJ), 10-m (T10) and 30-m sprint time (T30), change-of-direction ability (COD), kicking velocity (KV), and maximal oxygen uptake (VO2max). External match load was quantified using GPS technology. Results: Both categories showed significant improvements in body composition, with higher %MM and lower %FM and 6skf (p < .05). CMJ, T30, and KV also improved significantly, whereas VO2max remained unchanged. Correlation analyses identified significant associations between physical fitness, body composition, and external match load, with more relationships observed in U18 than U21 players. Conclusions: Elite youth football players improved primarily in neuromuscular performance and body composition across the season. The greater number of associations observed in U18 players represents an exploratory pattern and should not be interpreted as evidence of stronger relationships between physical qualities and match performance compared with U21 players.
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Bangsbo, J., Mohr, M., & Krustrup, P. (2006). Physical and metabolic demands of training and match-play in the elite football player. Journal of Sports Sciences, 24(7), 665–674. https://doi.org/10.1080/02640410500482529 DOI: https://doi.org/10.1080/02640410500482529
Buchheit, M., & Mendez-Villanueva, A. (2013). Reliability and stability of anthropometric and performance measures in highly-trained young soccer players: Effect of age and maturation. Journal of Sports Sciences, 31(12), 1332–1343. https://doi.org/10.1080/02640414.2013.781662 DOI: https://doi.org/10.1080/02640414.2013.781662
Clemente, F. M., Nikolaidis, P. T., Rosemann, T., & Knechtle, B. (2019). Dose-response relationship between external load variables, body composition, and fitness variables in professional soccer players. Frontiers in Physiology, 10, Article 443. https://doi.org/10.3389/fphys.2019.00443 DOI: https://doi.org/10.3389/fphys.2019.00443
Clemente, F. M., Silva, R., Castillo, D., Los Arcos, A., Mendes, B., & Afonso, J. (2020). Weekly load variations of distance-based variables in professional soccer players: A full-season study. International Journal of Environmental Research and Public Health, 17(9), Article 3300. https://doi.org/10.3390/ijerph17093300 DOI: https://doi.org/10.3390/ijerph17093300
Cummins, C., Orr, R., O'Connor, H., & West, C. (2013). Global positioning systems (GPS) and microtechnology sensors in team sports: A systematic review. Sports Medicine, 43(10), 1025–1042. https://doi.org/10.1007/s40279-013-0069-2 DOI: https://doi.org/10.1007/s40279-013-0069-2
Díez-Fernández, D. M., Rodríguez-Rosell, D., Gazzo, F., Giráldez, J., Villaseca-Vicuña, R., & González-Jurado, J. A. (2022). Can the Supido radar be used for measuring ball speed during soccer kicking? A reliability and concurrent validity study of a new low-cost device. Sensors, 22(18), Article 7046. https://doi.org/10.3390/s22187046 DOI: https://doi.org/10.3390/s22187046
Djaoui, L., Chamari, K., Owen, A. L., & Dellal, A. (2017). Maximal sprinting speed of elite soccer players during training and matches. Journal of Strength and Conditioning Research, 31(6), 1509–1517. https://doi.org/10.1519/JSC.0000000000001642 DOI: https://doi.org/10.1519/JSC.0000000000001642
Dos'Santos, T., Thomas, C., Comfort, P., & Jones, P. A. (2018). The effect of angle and velocity on change of direction biomechanics: An angle-velocity trade-off. Sports Medicine, 48(10), 2235–2253. https://doi.org/10.1007/s40279-018-0968-3 DOI: https://doi.org/10.1007/s40279-018-0968-3
Ford, P. R., Hodges, N. J., Broadbent, D., O'Connor, D., Scott, D., Datson, N., Andersson, H. A., & Williams, A. M. (2020). The developmental and professional activities of female international soccer players from five high-performing nations. Journal of Sports Sciences, 38(11–12), 1432–1440. https://doi.org/10.1080/02640414.2020.1789384 DOI: https://doi.org/10.1080/02640414.2020.1789384
Gualtieri, A., Rampinini, E., Dello Iacono, A., & Beato, M. (2023). High-speed running and sprinting in professional adult soccer: Current thresholds definition, match demands and training strategies. A systematic review. Frontiers in Sports and Active Living, 5, Article 1116293. https://doi.org/10.3389/fspor.2023.1116293 DOI: https://doi.org/10.3389/fspor.2023.1116293
Kobal, R., Loturco, I., Gil, S., Cal Abad, C. C., Cuniyochi, R., Barroso, R., & Tricoli, V. (2016). Comparison of physical performance among Brazilian elite soccer players of different age-categories. Journal of Sports Medicine and Physical Fitness, 56(4), 376–382.
Lloyd, R. S., Oliver, J. L., Faigenbaum, A. D., Howard, R., De Ste Croix, M. B. A., Williams, C. A., Best, T. M., Alvar, B. A., Micheli, L. J., Thomas, D. P., Hatfield, D. L., Cronin, J. B., & Myer, G. D. (2015). Long-term athletic development: Part 1: A pathway for all youth. Journal of Strength and Conditioning Research, 29(5), 1439–1450. https://doi.org/10.1519/JSC.0000000000000756 DOI: https://doi.org/10.1519/JSC.0000000000000756
Malone, J. J., Di Michele, R., Morgans, R., Burgess, D., Morton, J. P., & Drust, B. (2015). Seasonal training-load quantification in elite English Premier League soccer players. International Journal of Sports Physiology and Performance, 10(4), 489–497. https://doi.org/10.1123/ijspp.2014-0352 DOI: https://doi.org/10.1123/ijspp.2014-0352
Malone, J. J., Lovell, R., Varley, M. C., & Coutts, A. J. (2017). Unpacking the black box: Applications and considerations for using GPS devices in sport. International Journal of Sports Physiology and Performance, 12(Suppl. 2), S2-18–S2-26. https://doi.org/10.1123/ijspp.2016-0236 DOI: https://doi.org/10.1123/ijspp.2016-0236
Moran, J., Parry, D. A., Lewis, I., Collison, J., Rumpf, M. C., & Sandercock, G. R. H. (2018). Maturation-related adaptations in running speed in response to sprint training in youth soccer players. Journal of Science and Medicine in Sport, 21(5), 538–542. https://doi.org/10.1016/j.jsams.2017.09.012 DOI: https://doi.org/10.1016/j.jsams.2017.09.012
Pareja-Blanco, F., Sánchez-Medina, L., Suárez-Arrones, L., & González-Badillo, J. J. (2017). Effects of velocity loss during resistance training on performance in professional soccer players. International Journal of Sports Physiology and Performance, 12(4), 512–519. https://doi.org/10.1123/ijspp.2016-0170 DOI: https://doi.org/10.1123/ijspp.2016-0170
Pareja-Blanco, F., Walker, S., & Häkkinen, K. (2020). Validity of using velocity to estimate intensity in resistance exercises in men and women. International Journal of Sports Medicine, 41(14), 1047–1055. https://doi.org/10.1055/a-1171-2287 DOI: https://doi.org/10.1055/a-1171-2287
Pérez-Contreras, J., Villaseca-Vicuña, R., Miarka, B., Merino-Muñoz, P., Hermosilla-Palma, F., & Aedo-Muñoz, E. (2024). Intratest reliability of the modified 505 test in adult male professional soccer players. Journal of Physical Education and Sport, 24(2), 407–411. https://doi.org/10.7752/jpes.2024.02049 DOI: https://doi.org/10.7752/jpes.2024.02049
Pérez-Contreras, J., Villaseca-Vicuña, R., Zapata-Huenullán, C., Benavides-Roca, L., Merino-Muñoz, P., & Vidal-Maturana, F. (2022). Condición física de futbolistas adultos y jóvenes de un equipo profesional de Nicaragua. Revista Ciencias de la Actividad Física, 23(2), 1–14. https://doi.org/10.29035/rcaf.23.2.4 DOI: https://doi.org/10.29035/rcaf.23.2.4
Rada, A., Kuvačić, G., De Giorgio, A., Sellami, M., Ardigò, L. P., Bragazzi, N. L., & Padulo, J. (2019). The ball kicking speed: A new, efficient performance indicator in youth soccer. PLOS ONE, 14(5), Article e0217101. https://doi.org/10.1371/journal.pone.0217101 DOI: https://doi.org/10.1371/journal.pone.0217101
Rios-Limas, I., Herrera-Amante, C. A., Carvajal-Veitía, W., Yáñez-Sepúlveda, R., Ayala-Guzmán, C. I., Ortiz-Hernández, L., López-Sagarra, A., Lorente-Solá, P., & López-Gil, J. F. (2025). Relating anthropometric profile to countermovement jump performance and external match load in Mexican national team soccer players: An exploratory study. Sports, 13(7), Article 236. https://doi.org/10.3390/sports13070236 DOI: https://doi.org/10.3390/sports13070236
Romero-Caballero, A., Varela-Olalla, D., & Loëns-Gutiérrez, C. (2021). Fitness evaluation in young and amateur soccer players: Reference values for vertical jump and aerobic fitness in men and women. Science & Sports, 36(2), 141.e1–141.e7. https://doi.org/10.1016/j.scispo.2020.04.004 DOI: https://doi.org/10.1016/j.scispo.2020.04.004
Stevens, T. G. A., de Ruiter, C. J., Twisk, J. W. R., Savelsbergh, G. J. P., & Beek, P. J. (2017). Quantification of in-season training load relative to match load in professional Dutch Eredivisie football players. Science and Medicine in Football, 1(2), 117–125. https://doi.org/10.1080/24733938.2017.1282163 DOI: https://doi.org/10.1080/24733938.2017.1282163
Villaseca-Vicuña, R., Barrera-Díaz, J., Otero-Saborido, F., Zabaloy, S., Palorames, E., & Sarmento, H. (2026). Key performance indicators in elite female football: Associations between sprints, duels, and match results. International Journal of Sports Physiology and Performance, 21(3), 448–455. https://doi.org/10.1123/ijspp.2025-0408 DOI: https://doi.org/10.1123/ijspp.2025-0408
Villaseca-Vicuña, R., Cursach, J., Medrano, V., Lobos, C., Rojas Moya, C., Faúndez Saavedra, D., Merino Muñoz, P., Cortés-Roco, G., Brooklyn Campbell, B., & Pérez-Contreras, J. (2025). Assessment of weekly workload in relation to match workload in U-21 football: Analysis of ten competition microcycles. Journal of Physical Education and Sport, 25(12), 2503–2510. https://doi.org/10.7752/jpes.2025.12277 DOI: https://doi.org/10.7752/jpes.2025.12277
Villaseca-Vicuña, R., Gayán-Candia, A., Gazzo, F., Giráldez, J., Zabaloy, S., & González-Jurado, J. A. (2024). Comparison of two warm-up protocols for physical and technical-decisional performance in young football players. Physical Activity Review, 12(1), 1–12. https://doi.org/10.16926/par.2024.12.01 DOI: https://doi.org/10.16926/par.2024.12.01
Villaseca-Vicuña, R., Medrano, V., Lobos, C., Rojas Moya, C., Cursach, J., Faúndez Saavedra, D., Merino Muñoz, P., Cortés-Roco, G., Brooklyn Campbell, B., & Pérez-Contreras, J. (2025). Comparison of physical fitness and body composition by age categories in young professional football players in Chile. Retos, 72, 445–457. https://doi.org/10.47197/retos.v72.116780 DOI: https://doi.org/10.47197/retos.v72.116780
Villaseca-Vicuña, R., Merino-Muñoz, P., Cortés-Roco, G., Escobar, N., Lara, M. M., Sepúlveda, R. Y., Barrera-Díaz, J., & Pérez-Contreras, J. (2026). Differences in physical performance according to contextual variables in U21 football players. Physiologia, 6(1), Article 8. https://doi.org/10.3390/physiologia6010008 DOI: https://doi.org/10.3390/physiologia6010008
Villaseca-Vicuña, R., Molina-Sotomayor, E., Zabaloy, S., & González-Jurado, J. A. (2021). Anthropometric profile and physical fitness performance comparison by game position in the Chile women's senior national football team. Applied Sciences, 11(5), Article 2004. https://doi.org/10.3390/app11052004 DOI: https://doi.org/10.3390/app11052004
Villaseca-Vicuña, R., Otero-Saborido, F. M., Pérez-Contreras, J., & González-Jurado, J. A. (2021). Relationship between physical fitness and match performance parameters of Chile women's national football team. International Journal of Environmental Research and Public Health, 18(16), Article 8412. https://doi.org/10.3390/ijerph18168412 DOI: https://doi.org/10.3390/ijerph18168412
Winter, E. M., & Maughan, R. J. (2009). Requirements for ethics approvals. Journal of Sports Sciences, 27(10), 985. https://doi.org/10.1080/02640410903178344 DOI: https://doi.org/10.1080/02640410903178344
World Medical Association. (2013). World Medical Association Declaration of Helsinki: Ethical principles for medical research involving human subjects. JAMA, 310(20), 2191–2194. https://doi.org/10.1001/jama.2013.281053 DOI: https://doi.org/10.1001/jama.2013.281053