Our aim was to characterize front crawl swimming performed at very high intensity by young practitioners. 114 swimmers 11–13 years old performed 25 m front crawl swimming at 50 m pace. Two underwater cameras was used to assess general biomechanical parameters (velocity, stroke rate, stroke length and stroke index) and interarm coordination (Index of Coordination), being also identified each front crawl stroke phase. Swimmers presented lower values in all biomechanical parameters than data presented in studies conducted with older swimmers, having the postpubertal group closest values to adult literature due to their superior anthropometric and maturational characteristics. Boys showed higher velocity and stroke index than girls (as reported for elite swimmers), but higher stroke rate than girls (in opposition to what is described for adults). In addition, when considering the total sample, a higher relationship was observed between velocity and stroke length (than with stroke rate), indicating that improving stroke length is a fundamental skill to develop in these ages. Furthermore, only catch-up coordination mode was adopted (being evident a lag time between propulsion of the arms), and the catch and the pull phases presented the highest and smallest durations, respectively.
Ana Silva, Pedro Figueiredo, Susana Soares, Ludovic Seifert, João Paulo Vilas-Boas and Ricardo J. Fernandes
Matheus Hausen, Pedro Paulo Soares, Marcus Paulo Araujo, Débora Esteves, Hilbert Julio, Roberto Tauil, Marcus Junca, Flávia Porto, Emerson Franchini, Craig Alan Bridge and Jonas Gurgel
Purpose: To propose and validate new taekwondo-specific cardiopulmonary exercise tests. Methods: Twelve male national-level taekwondo athletes (age 20  y, body mass 67.5 [5.7] kg, height 175  cm, and training experience 7  y) performed 3 separate exercise tests in a randomized counterbalanced order: (1) a treadmill running cardiopulmonary exercise test (CPET) and (2) continuous and (3) interval taekwondo-specific cardiopulmonary exercise tests (cTKDet and iTKDet, respectively). The CPET was administered using an individualized ramp protocol. Taekwondo tests comprised sequences of turning kicks performed on a stationary target. The impacts were recorded via an electronic scoring sensor used in official competition. Stages on the cTKDet and iTKDet lasted 1 min and progressively reduced the kick interval duration. These were guided by a sound signal, starting with 4.6 s between kicks and reducing by 0.4 s every minute until the test ended. Oxygen uptake (