title: Tracking the performance, energetics and biomechanics of international versus national level swimmers during a competitive season.
abstract: The purpose of this study was to track and compare the changes of performance, energetic and biomechanical profiles of international (Int) and national (Nat) level swimmers during a season. Ten Portuguese male swimmers (four Int and six Nat level subjects) were evaluated on three different time periods (TP(1), TP(2), TP(3)) of the 2009-2010 season. Swimming performance was assessed based on official time's lists of the 200-m freestyle event. An incremental set of 7 × 200 m swims was applied to assess the energetic and biomechanical data. Measurements were made of: (1) velocity at the 4 mmol of lactate levels (V4), stroke index at V4 (SI@V4) and propelling efficiency at V4 (η (p)@V4), as energetic estimators; (2) stroke length at V4 (SL@V4) and stroke frequency at V4 (SF@V4), as biomechanical variables. The results demonstrated no significant variations in all variables throughout the season. The inter-group comparison pointed out higher values for Int swimmers, with statistical differences for the 200 m performance in all time periods. Near values of the statistical significance were demonstrated for the SI@V4 in TP(1) and TP(3). The tracking based on K values was high only for the SI@V4. It is concluded that a high stability can be observed for elite swimmers performance, energetic and biomechanical profiles throughout a single season. Int swimmers are able to maintain a higher energetic and biomechanical capacity than Nat ones at all times. The SI@V4 may be used as an indicator of performance variation.
authors.affiliation: Sport Sciences Department, Polytechnic Institute of Bragança, Campus Sta. Apolónia, Ap. 1101-75, 5300 Bragança, Portugal. mario.costa@ipb.pt
authors.forename: Mário J
authors.initials: MJ
authors.lastname: Costa
authors.forename: José A
authors.initials: JA
authors.lastname: Bragada
authors.forename: Jean E
authors.initials: JE
authors.lastname: Mejias
authors.forename: Hugo
authors.initials: H
authors.lastname: Louro
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Marinho
authors.forename: António J
authors.initials: AJ
authors.lastname: Silva
authors.forename: Tiago M
authors.initials: TM
authors.lastname: Barbosa
mesh_terms: D000293:Adolescent; D000328:Adult; D056352:Athletes; D054874:Athletic Performance / Q000502:physiology*; D001696:Biomechanical Phenomena / Q000502:physiology*; D003163:Competitive Behavior / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D006801:Humans; D038622:Internationality; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods; D011174:Portugal; D012621:Seasons; D013550:Swimming / Q000502:physiology*; D055815:Young Adult