{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T03:34:34Z","timestamp":1760240074607,"version":"build-2065373602"},"reference-count":22,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2019,3,4]],"date-time":"2019-03-04T00:00:00Z","timestamp":1551657600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sports"],"abstract":"<jats:p>Physiological responses related to 400-m front crawl performance were examined in a 11-week training macrocycle in children 11.6 \u00b1 1.2 years old. Fourteen girls and twenty-nine boys completed a maximum intensity 400-m test, at the beginning (\u03a41) and at the end of four weeks of general preparation (\u03a42), four weeks of specific preparation (\u03a43), and three weeks of the competitive period (\u03a44). Blood lactate (La), blood glucose (Glu) and heart rate were measured post effort. Stroke rate (SR), stroke length (SL) and stroke index (SI) were measured during the test. The 400-m time was decreased at T2, T3, and T4 compared to T1 by 4.2 \u00b1 4.9, 7.5 \u00b1 7.0, and 8.6 \u00b1 7.3% (p &lt; 0.05) and at T3 and T4 compared to T2 by 3.1 \u00b1 4.3 and 4.2 \u00b1 4.6%, respectively (p &lt; 0.05). La was not different between tests (p &gt; 0.05) and Glu was decreased at T3 compared to other testing moments (p &lt; 0.05). SR, SL, and SI were higher at T3 and T4 compared to T1 (p &lt; 0.05). SL and SI were also increased at T4 compared to T2 (p &lt; 0.05). Performance changes from T1 to T2 were related to SL and SI changes (r = 0.45 and 0.83, p &lt; 0.05), and subsequent changes between T2 to T3 were related to SR, SI, La, and Glu changes (r = 0.48, 0.68, 0.34, and 0.42, p &lt; 0.05). Performance change from T3 to T4 was related to SL, SI, and La modifications (r = 0.34, 0.70, and 0.53, p &lt; 0.05). Performance gains may be related to various biomechanical or physiological changes according to training macrocycle structure.<\/jats:p>","DOI":"10.3390\/sports7030057","type":"journal-article","created":{"date-parts":[[2019,3,4]],"date-time":"2019-03-04T05:22:26Z","timestamp":1551676946000},"page":"57","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Physiological and Biomechanical Evaluation of a Training Macrocycle in Children Swimmers"],"prefix":"10.3390","volume":"7","author":[{"given":"Sara","family":"Ferreira","sequence":"first","affiliation":[{"name":"Centre of Research, Education, Innovation and Intervention in Sport, Faculty of Sport, University of Porto, 4200-450 Porto, Portugal"},{"name":"Porto Biomechanics Laboratory, University of Porto, 4200-450 Porto, Portugal"}]},{"given":"Diogo","family":"Carvalho","sequence":"additional","affiliation":[{"name":"Centre of Research, Education, Innovation and Intervention in Sport, Faculty of Sport, University of Porto, 4200-450 Porto, Portugal"},{"name":"Porto Biomechanics Laboratory, University of Porto, 4200-450 Porto, Portugal"}]},{"given":"Ana","family":"Monteiro","sequence":"additional","affiliation":[{"name":"Centre of Research, Education, Innovation and Intervention in Sport, Faculty of Sport, University of Porto, 4200-450 Porto, Portugal"},{"name":"Porto Biomechanics Laboratory, University of Porto, 4200-450 Porto, Portugal"}]},{"given":"Jos\u00e9 Arturo","family":"Abraldes","sequence":"additional","affiliation":[{"name":"Faculty of Sport Science, University of Murcia, 30720 San Javier, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4109-2939","authenticated-orcid":false,"given":"Jo\u00e3o","family":"Vilas-Boas","sequence":"additional","affiliation":[{"name":"Centre of Research, Education, Innovation and Intervention in Sport, Faculty of Sport, University of Porto, 4200-450 Porto, Portugal"},{"name":"Porto Biomechanics Laboratory, University of Porto, 4200-450 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2040-354X","authenticated-orcid":false,"given":"Argyris","family":"Toubekis","sequence":"additional","affiliation":[{"name":"School of P.E. & Sport Science, National and Kapodistrian University of Athens, 17237 Athens, Greece"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5811-0443","authenticated-orcid":false,"given":"Ricardo","family":"Fernandes","sequence":"additional","affiliation":[{"name":"Centre of Research, Education, Innovation and Intervention in Sport, Faculty of Sport, University of Porto, 4200-450 Porto, Portugal"},{"name":"Porto Biomechanics Laboratory, University of Porto, 4200-450 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2019,3,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1103","DOI":"10.2165\/00007256-200333150-00003","article-title":"A framework for understanding the training process leading to elite performance","volume":"33","author":"Smith","year":"2003","journal-title":"Sports Med."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1183","DOI":"10.1080\/02640414.2011.587196","article-title":"Stability of elite freestyle performance from childhood to adulthood","volume":"29","author":"Costa","year":"2011","journal-title":"J. Sports Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"409","DOI":"10.1123\/pes.24.3.409","article-title":"Front crawl technical characterization of 11- to 13-year-old swimmers","volume":"24","author":"Silva","year":"2012","journal-title":"Pediatr. Exerc. Sci."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1016\/j.humov.2014.07.005","article-title":"Longitudinal modeling in sports: Young swimmers\u2019 performance and biomechanics profile","volume":"37","author":"Morais","year":"2014","journal-title":"Hum. Mov. Sci."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Silva, A., Figueiredo, P., Ribeiro, J., Alves, F., Vilas-Boas, J.P., Seifert, L., and Fernandes, R. (2019). Integrated analysis of young swimmers\u2019 sprint performance. Motor Control.","DOI":"10.1123\/mc.2018-0014"},{"key":"ref_6","first-page":"761","article-title":"Do traditional and reverse swimming training periodizations lead to similar aerobic performance improvements?","volume":"58","author":"Fernandes","year":"2018","journal-title":"J. Sports Med. Phys. Fit."},{"key":"ref_7","first-page":"e184","article-title":"Hydrodynamic profile of young swimmers: Changes over a competitive season","volume":"25","author":"Barbosa","year":"2016","journal-title":"Scand. J. Med. Sci. Sports"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1029","DOI":"10.1007\/s00421-010-1586-4","article-title":"High-intensity interval training improves VO2peak, maximal lactate accumulation, time trial and competitive performance in 9\u201311 year-old swimmers","volume":"110","author":"Sperlich","year":"2010","journal-title":"Eur. J. Appl. Physiol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1519\/JSC.0000000000001879","article-title":"Effect of an 11-week in-water training program with increased resistance on the swimming performance and the basic kinematic characteristics of the front crawl stroke","volume":"33","author":"Gourgoulis","year":"2019","journal-title":"J. Strength Cond. Res."},{"key":"ref_10","unstructured":"Zacca, R., Azevedo, R., Chainok, P., Vilas-Boas, J.-P., Castro, F.A.S., Pyne, D.B., and Fernandes, R.J. (2018). Monitoring age-group swimmers over a training macrocycle: Energetic, technique, and anthropometrics. J. Strength Cond. Res."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Zacca, R., Azevedo, R., Ramos, V.R., Abraldes, J.A., Vilas-Boas, J.-P., Castro, F.A.S., Pyne, D.B., and Fernandes, R.J. (2019). Biophysical follow-up of age-group swimmers during a traditional three-peak preparation program. J. Strength Cond. Res.","DOI":"10.1519\/JSC.0000000000002964"},{"key":"ref_12","first-page":"117","article-title":"Physical development and swimming performance during biological maturation in young female swimmers","volume":"1","author":"Latt","year":"2009","journal-title":"Coll. Anthropol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"297","DOI":"10.2466\/pms.108.1.297-307","article-title":"Longitudinal development of physical and performance parameters during biological maturation of young male swimmers","volume":"108","author":"Latt","year":"2009","journal-title":"Percept. Mot. Skills"},{"key":"ref_14","first-page":"373","article-title":"Does energy cost of swimming affect time to exhaustion at the individual\u2019s maximal oxygen consumption velocity?","volume":"46","author":"Fernandes","year":"2006","journal-title":"J. Sports Med. Phys. Fit."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"90","DOI":"10.1055\/s-2001-11343","article-title":"Effect of aerobic training and detraining on left ventricular dimensions and diastolic function in prepubertal boys and girls","volume":"22","author":"Obert","year":"2001","journal-title":"Int. J. Sports Med."},{"key":"ref_16","unstructured":"Tanner, J.M., and Whitehouse, R.H. (1982). Atlas of Children\u2019s Growth Normal Variation and Growth Disorders, Academic Press."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1249\/00005768-198205000-00012","article-title":"Psychophysical bases of perceived exertion","volume":"14","author":"Borg","year":"1982","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"S17","DOI":"10.1139\/h2004-055","article-title":"Changes in physiological and stroke parameters during a maximal 400-m free swimming test in elite swimmers","volume":"29","author":"Laffite","year":"2004","journal-title":"Can. Appl. Physiol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"835","DOI":"10.1055\/s-0031-1279778","article-title":"Glucose response after a ten-week training in swimming","volume":"32","author":"Sengoku","year":"2011","journal-title":"Int. J. Sports Med."},{"key":"ref_20","first-page":"319","article-title":"Different levels of hydration following a training session on swimming performance","volume":"6","author":"Toubekis","year":"2006","journal-title":"Port. J. Sport Sci."},{"key":"ref_21","first-page":"335","article-title":"Effect of dietary carbohydrate content on blood glucose levels of swimmers during training","volume":"48","author":"Soultanakis","year":"2008","journal-title":"J. Sports Med. Phys. Fit."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"601","DOI":"10.1249\/MSS.0b013e3181621ec4","article-title":"Determinants of heart rate recovery following exercise in children","volume":"40","author":"Singh","year":"2008","journal-title":"Med. Sci. Sports Exerc."}],"container-title":["Sports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-4663\/7\/3\/57\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T12:36:02Z","timestamp":1760186162000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-4663\/7\/3\/57"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,3,4]]},"references-count":22,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2019,3]]}},"alternative-id":["sports7030057"],"URL":"https:\/\/doi.org\/10.3390\/sports7030057","relation":{},"ISSN":["2075-4663"],"issn-type":[{"type":"electronic","value":"2075-4663"}],"subject":[],"published":{"date-parts":[[2019,3,4]]}}}