{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T17:28:47Z","timestamp":1785432527761,"version":"3.56.0"},"reference-count":31,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2026,7,18]],"date-time":"2026-07-18T00:00:00Z","timestamp":1784332800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100008530","name":"ERDF","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100008530","id-type":"DOI","asserted-by":"crossref"}]},{"id":[{"id":"https:\/\/ror.org\/01rkhv978","id-type":"ROR","asserted-by":"publisher"}]},{"name":"Regional Government of Castilla-La Mancha"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JFMK"],"abstract":"<jats:p>Background: This study aimed to identify the field-based technical and biomechanical variables that best discriminate and predict competitive performance in 11\u201312-year-old swimmers. Methods: Seventy-two federated swimmers were assessed during a controlled technical evaluation session conducted four weeks prior to the Under-13 (U\u201313) Regional Championship. Variables measured included 25 m freestyle time and velocity, 25 m kick time and velocity, turn time and velocity using the 5 m in\u20135 m out criterion, stroke count, stroke length, and swimming efficiency index. Aqua Points were obtained from official championship results held one month after testing. Swimmers were categorized into three performance groups according to Aqua Points classification: low, medium, and high competitive level. A multiple linear regression analysis was performed to identify predictors of competitive performance. Results: Significant differences were observed between competitive levels for 25 m freestyle time and velocity, kick performance, turn time and velocity, and swimming efficiency (p &lt; 0.05), with progressive improvements as Aqua Points increased. Significant differences were also observed for stroke count and stroke length, suggesting that stroke mechanics contributed to performance differentiation within this age group. In the regression analysis, 25 m freestyle velocity and turn velocity emerged as the strongest predictors of competitive performance, while sex was a significant covariate. The final model explained a large proportion of the variance in Aqua Points (R2 = 0.846, adjusted R2 = 0.832, p &lt; 0.001). Conclusions: Competitive level in 11\u201312-year-old swimmers is strongly associated with technical proficiency, particularly short-distance swimming speed and turn execution. These findings highlight the importance of technical development during formative stages and provide practical insights for coaching strategies.<\/jats:p>","DOI":"10.3390\/jfmk11030278","type":"journal-article","created":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T02:32:08Z","timestamp":1784514728000},"page":"278","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Effect of Aqua Points Level on Speed, Efficiency, and Turn Performance in Youth Swimmers Aged 11\u201312 Years"],"prefix":"10.3390","volume":"11","author":[{"given":"Alejandro","family":"L\u00f3pez-Hern\u00e1ndez","sequence":"first","affiliation":[{"name":"Sport Training Laboratory, Faculty of Sports Sciences, University of Castilla-La Mancha, 45071 Toledo, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-0616-1980","authenticated-orcid":false,"given":"Jos\u00e9 Francisco","family":"Alonso Ramos","sequence":"additional","affiliation":[{"name":"Sport Training Laboratory, Faculty of Sports Sciences, University of Castilla-La Mancha, 45071 Toledo, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5851-523X","authenticated-orcid":false,"given":"Juan \u00c1ngel","family":"Sim\u00f3n Piqueras","sequence":"additional","affiliation":[{"name":"Faculty of Education of Albacete, University of Castilla-La Mancha, 02071 Albacete, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Miriam","family":"De la Torre Maroto","sequence":"additional","affiliation":[{"name":"Castilla-la-Mancha Swimming Federation, Castilla-la-Mancha, 02001 Albacete, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5953-4742","authenticated-orcid":false,"given":"Jos\u00e9 Mar\u00eda","family":"Gonz\u00e1lez Rav\u00e9","sequence":"additional","affiliation":[{"name":"Sport Training Laboratory, Faculty of Sports Sciences, University of Castilla-La Mancha, 45071 Toledo, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"262","DOI":"10.1016\/j.jsams.2009.01.003","article-title":"Energetics and biomechanics as determining factors of swimming performance: Updating the state of the art","volume":"13","author":"Barbosa","year":"2010","journal-title":"J. Sci. Med. Sport"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"8","DOI":"10.2165\/00007256-199213010-00002","article-title":"Biomechanics of competitive front crawl swimming","volume":"13","author":"Toussaint","year":"1992","journal-title":"Sports Med."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1007\/s00421-004-1281-4","article-title":"An energy balance of front crawl","volume":"94","author":"Zamparo","year":"2005","journal-title":"Eur. J. Appl. Physiol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"311","DOI":"10.1016\/0021-9290(92)90028-Y","article-title":"Active drag, useful mechanical power output, and hydrodynamic force coefficient in different swimming strokes at maximal velocity","volume":"25","author":"Kolmogorov","year":"1992","journal-title":"J. Biomech."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Sorgente, V., Agudo-Ortega, A., Lopez-Hernandez, A., Santos del Cerro, J., Minciacchi, D., and Gonz\u00e1lez Rav\u00e9, J.M. (2023). Relationship between Maximum Force\u2013Velocity Exertion and Swimming Performances among Four Strokes over Medium and Short Distances: The Stronger on Dry Land, the Faster in Water?. J. Funct. Morphol. Kinesiol., 8.","DOI":"10.3390\/jfmk8010020"},{"key":"ref_6","first-page":"189","article-title":"Analysis of 50-, 100-, and 200-m freestyle swimmers at the 1992 Olympic Games","volume":"10","author":"Arellano","year":"1994","journal-title":"J. Appl. Biomech."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1080\/14763140208522784","article-title":"Swimming: Biomechanical analysis of the grab, track and handle swimming starts: An intervention study","volume":"1","author":"Blanksby","year":"2002","journal-title":"Sport Biomech."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"766","DOI":"10.1080\/02640414.2015.1069382","article-title":"Underwater and surface strategies of 200 m world-level swimmers","volume":"34","author":"Veiga","year":"2016","journal-title":"J. Sports Sci."},{"key":"ref_9","first-page":"7","article-title":"A kinematic and kinetic analysis of the freestyle and butterfly turns","volume":"12","author":"Lyttle","year":"1997","journal-title":"J. Sci. Med. Sport"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1080\/14763141.2016.1179782","article-title":"Effect of the starting and turning performances on the subsequent swimming parameters of elite swimmers","volume":"16","author":"Veiga","year":"2017","journal-title":"Sports Biomech."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Malina, R.M., Bouchard, C., and Bar-Or, O. (2004). Growth, Maturation, and Physical Activity, Human Kinetics. [2nd ed.].","DOI":"10.5040\/9781492596837"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"61","DOI":"10.1519\/SSC.0b013e31825760ea","article-title":"The youth physical development model: A new approach to long-term athletic development","volume":"34","author":"Lloyd","year":"2012","journal-title":"Strength. Cond. J."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"198","DOI":"10.1123\/ijspp.2015-0420","article-title":"Determinant factors of long-term performance development in young swimmers","volume":"12","author":"Morais","year":"2017","journal-title":"Int. J. Sports Physiol. Perform."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"767","DOI":"10.1007\/s00421-010-1696-z","article-title":"An energy balance of the 200 m front crawl race","volume":"111","author":"Figueiredo","year":"2011","journal-title":"Eur. J. Appl. Physiol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"349","DOI":"10.1007\/s42978-020-00082-1","article-title":"Investigating the Modulatory Role of Chronological and Biological Age on Performance Predictors in Youth Swimmers","volume":"2","author":"McNarry","year":"2020","journal-title":"J. Sci. Sport Exerc."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"85","DOI":"10.5114\/hm.2023.117469","article-title":"Contribution of biological maturation and power of upper and lower limbs to crawl swimming performance in young swimmers","volume":"24","author":"Silva","year":"2022","journal-title":"Hum. Mov."},{"key":"ref_17","unstructured":"(2026, July 07). World Aquatics. Swimming Points. Available online: https:\/\/www.worldaquatics.com\/swimming\/points."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Santos, C.C., Garrido, N.D., Cuenca-Fern\u00e1ndez, F., Marinho, D.A., and Costa, M.J. (2023). Performance Tiers within a Competitive Age Group of Young Swimmers Are Characterized by Different Kinetic and Kinematic Behaviors. Sensors, 23.","DOI":"10.3390\/s23115113"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"319","DOI":"10.1007\/s40279-013-0117-y","article-title":"Warm-up and performance in competitive swimming","volume":"44","author":"Neiva","year":"2014","journal-title":"Sports Med."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1186\/s40798-022-00514-y","article-title":"Swimming Warm-Up and Beyond: Dryland Protocols and Their Related Mechanisms-A Scoping Review","volume":"8","author":"Boullosa","year":"2022","journal-title":"Sports Med. Open."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1123\/ijsnem.2014-0047","article-title":"Physical and energy requirements of competitive swimming events","volume":"24","author":"Pyne","year":"2014","journal-title":"Int. J. Sport Nutr. Exerc. Metab."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"426","DOI":"10.1016\/j.humov.2009.11.003","article-title":"Arm coordination, power, and swim efficiency in national and regional front crawl swimmers","volume":"29","author":"Seifert","year":"2010","journal-title":"Hum. Mov. Sci."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"480","DOI":"10.1080\/14763141.2012.670663","article-title":"Power production of the lower limbs in flutter-kick swimming","volume":"11","author":"Gatta","year":"2012","journal-title":"Sports Biomech."},{"key":"ref_24","first-page":"563206","article-title":"Relative Contribution of Arms and Legs in 30 s Fully Tethered Front Crawl Swimming","volume":"2015","author":"Marinho","year":"2015","journal-title":"Biomed. Res. Int."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1080\/14763141.2018.1435713","article-title":"Start and turn performances of elite sprinters at the 2016 European Championships in swimming","volume":"18","author":"Morais","year":"2019","journal-title":"Sports Biomech."},{"key":"ref_26","first-page":"278","article-title":"Relationships of stroke rate, distance per stroke, and velocity in competitive swimming","volume":"11","author":"Craig","year":"1979","journal-title":"Med. Sci. Sports."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1784","DOI":"10.1249\/mss.0b013e3180f62f38","article-title":"Kinematic changes during a 100-m front crawl: Effects of performance level and gender","volume":"39","author":"Seifert","year":"2007","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Matjiur, R., Chainok, P., Lauer, J., Limroongreungrat, W., de Jesus, K., Zacca, R., Fernandes, R.J., and Vilas-Boas, J.P. (2025). Sex-based differences in front crawl and butterfly sprint performance in age-group swimmers. PLoS ONE, 20.","DOI":"10.1371\/journal.pone.0339480"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"653","DOI":"10.1016\/j.psychsport.2006.07.002","article-title":"The ecological dynamics of decision making in sport","volume":"7","author":"Davids","year":"2006","journal-title":"Psychol. Sport Exerc."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"245","DOI":"10.2165\/00007256-200333040-00001","article-title":"Movement systems as dynamical systems: The functional role of variability and its implications for sports medicine","volume":"33","author":"Davids","year":"2003","journal-title":"Sports Med."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"L\u00f3pez-Hern\u00e1ndez, A., Sim\u00f3n-Piqueras, J.\u00c1., Zamorano-Garc\u00eda, D., Pyne, D.B., and Rav\u00e9, J.M.G. (2025). Impact of psychosocial intervention on performance determinants in competitive swimmers: Roles of coach, family, environment, and athlete characteristics. Sports, 13.","DOI":"10.3390\/sports13090314"}],"container-title":["Journal of Functional Morphology and Kinesiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2411-5142\/11\/3\/278\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T04:10:21Z","timestamp":1784520621000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2411-5142\/11\/3\/278"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,18]]},"references-count":31,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["jfmk11030278"],"URL":"https:\/\/doi.org\/10.3390\/jfmk11030278","relation":{},"ISSN":["2411-5142"],"issn-type":[{"value":"2411-5142","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,18]]}}}