Browsing by Author "Fernandes, Ricardo J."
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- Acute effects of the use of a biofeedback system for the technical training in breaststroke swimmingPublication . Lima, António B.; Capitão, Fátima; Morouço, Pedro; Gonçalves, Pedro; Fernandes, Ricardo J.; Barbosa, Tiago M.; Velhote, Miguel C.; Tani, G.; Vilas-Boas, João PauloThe purpose of this research was to develop, validate, and evaluate a biofeedback system for the technical training in breaststroke swimming. The system lied on the assessment of speed fluctuation curves of an anatomical landmark of the swimmer(hip).
- Aportaciones desde la biomecánica de la natación de competiciónPublication . Vilas-Boas, João Paulo; Barbosa, Tiago M.; Lima, António B.; Soares, Susana; Fernandes, Ricardo J.A natação é uma modalidade individual, cíclica e fechada, pelo que, no respectivo quadro de factores determinantes do sucesso competitivo, a optimização do gesto técnico desempenha um papel determinante.
- Assessment of time limit at lowest speed corresponding to maximal oxygen consumption in the four competitive swimming strokesPublication . Fernandes, Ricardo J.; Cardoso, Carla; Silva, José; Vilar, Sónia; Colaço, Paulo; Barbosa, Tiago M.; Keskinen, Kari L.; Vilas-Boas, João PauloTime limit at lowest speed of maximal oxygen consumption (TLim-v O2max) was characterized in the 4 swimming strokes, and related with O2max and anaerobic threshold (AnT). 23 elite swimmers performed an incremental protocol for v O2max assessment. 48 hours later, Tlim-v O2max was assessed. O2 was directly measured BxB (K4 b2, Cosmed, Italy) and AnT was assessed individually (YSI 1500L Sport, USA). Tlim-v O2max values were 238.8±39.0, 246.1±51.9, 277.6±85.6 and 331.4±82.7 s in crawl, backstroke, butterfly, and breaststroke (no differences observed). No correlations were found between Tlim-v O2max and O2max, and AnT. However, inverse relationships were observed between Tlim-v O2max and v O2max (r=-0.63, p<0.01) and vAnT (r=-0.52, p=0.01), pointing out that the higher the velocities commonly related to aerobic proficiency, the lower the TLim- v O2max.
- Assessment of time limit at VO2max velocity in the 4 competitive swimming techniquesPublication . Fernandes, Ricardo J.; Cardoso, Carla; Silva, José; Vilar, Sónia; Colaço, Paulo; Barbosa, Tiago M.; Keskinen, Kari L.; Vilas-Boas, João PauloTime limit at the minimum velocity that elicits maximal oxygen consumption (TLim-v O2max) was studied both in flume (Billat et al., 1996) and in normal swimming conditions (Fernandes et al., 2003). While no studies have been carried out based on other swimming techniques than freestyle, the purpose of this experiment was to characterize, and compare, TLim-v O2max in the four competitive strokes, as well as to observe its relationships with two major performance determinants: O2max and anaerobic threshold (AnT).
- Bioenergetical profile of elite swimmersPublication . Barbosa, Tiago M.; Fernandes, Ricardo J.; Keskinen, Kari L.; Colaço, Paulo; Cardoso, Carla; Silva, José; Vilas-Boas, João Paulo
- Comparison of a continuous and intermittent triangular protocols for direct VO2max assessementPublication . Cardoso, Carla; Fernandes, Ricardo J.; Magalhães, Juan; Santos, Paulo; Colaço, Paulo; Soares, Susana; Carmo, Carla; Barbosa, Tiago M.; Vilas-Boas, João PauloThe purpose of this study was to compare two incremental protocols for V02max assessment and minimum swimming velocity that elicits V02max (vV02max). The sample comprised 11 Portuguese swimmers: 6 females (2 1.00± 1. 79 years, 54.83±3.71 kg, and 163.83±1.47 cm) and 5 males (25.40±2.79 years, 69.00±9.03 kg, and 175.00±9.03 cm). They performed two incremental protocols (starting at 0.9 m.s'\ with increments of 0.05 m.s,l per 200-m stage) for freestyle V02max assessment, with a 48h interval and in the same general conditions. One protocol was a continuous test and the other an intermittent one, with 30-s rest between incremental stages for [La-] assessment. Mean values of V02max, vV02max, VE, R, HR and [La-] for continuous and intermittent protocol, were respectively 52.5±9.44 m1.kg'l.min'l and 53.4±8.74 rnl.kg'l.min'l, 1.16±O.099 m.s) and 1.15±O.099 m.s-l, 95.3±26.32l.min,l and 95.8±26.60 l.min'l, 1.00±0.044 and 1.00±0.053, 183.l±9.47b.min'l and 187.5±8.44 b.min'l, 7.36±Ll313mM.rl and 8.86± 1.93hnM.r1. [La-] was the only different parameter between both protocols (p 0.05). Resnlts pointed out that both protocols were suitable for V02max and vV02max assessment in swimming.
- Contributos da biomecânica para o estudo do rendimento desportivo em nataçãoPublication . Vilas-Boas, João Paulo; Oliveira, Sara; Silva, Diana; Sousa, Ana Francisca; Ribeiro, João; Jesus, Kelly de; Costa, Lígia; Figueiredo, Pedro; Pereira, Suzana Matheus; Lima, António B.; Marinho, D.A.; Morouço, Pedro; Barbosa, Tiago M.; Silva, A.J.; Vaz, Mário; Velhote, Miguel C.; Soares, Susana; Sousa, Filipa; Machado, Leandro; Fernandes, Ricardo J.Na actualidade, o progresso do rendimento desportivo ao mais alto nível só é susceptível de ser conseguido através de uma combinação (que diríamos necessariamente feliz) de um vasto conjunto de factores: é necessário desde logo um pouco de sorte (como em tudo na vida – mesmo que seja para cozinhar a sopa de pedra requerida), mas sobretudo um praticante talentoso e motivado, condições de treino adequadas, um envolvimento global propício, uma equipa directiva competente e motivada e uma equipa técnica pluridisciplinar devidamente habilitada e coordenada. No quadro das habilitações desta deve-se destacar a sua sensibilidade e vocação para a contínua avaliação do seu próprio desempenho e do desempenho do seu nadador, para a consideração, ponderação e experimentação de novas opções, para a inovação tecnológica e científica. Apesar de no universo desportivo a inércia científica (e tecnológica) ser ainda superior à verificada noutros domínios da sociedade contemporânea (às vezes por estrito exercício de um carácter “bota de elástico”), são já muitos (e de há muito) os exemplos frutuosos da sua incorporação no quotidiano, seja como background cultural apenas, seja como prática efectiva. No futuro serão cada vez mais; e serão cada vez menos os espaços para o “por acaso”, para o “surpreendente”, para a geração espontânea do campeão apesar de quem o treina. No futuro – e num futuro que se já vem fazendo presente – não haverá nadadores ou treinadores de sucesso que não apelem, mais ou menos exuberantemente, a auxiliares científicos e tecnológicos para o treino.
- Economia de nado e tempo limite à velocidade mínima de vo2max: novas descobertasPublication . Barbosa, Tiago M.; Fernandes, Ricardo J.; Vilas-Boas, João PauloA economia de nado é uma área de investigação que teve como pioneiros, em Portugal, Vilas- Boas (1993) e Alves (1995). Passada uma década, novos momentos experimentais foram realizados e resultados up to date foram obtidos. As mais recentes metodologias foram empregues e, inclusivamente, uma nova área de treino parece ter emergido - o tempo até à exaustão à intensidade de nado correspondente à Potencia Aeróbia, isto é, ao consumo máximo de oxigénio (VO2max).
- Effects of protocol step length on biomechanical measures in swimmingPublication . Barbosa, Tiago M.; Jesus, Kelly de; Abraldes, J. Arturo; Ribeiro, João; Figueiredo, Pedro; Vilas-Boas, João Paulo; Fernandes, Ricardo J.The assessment of energetic and mechanical parameters in swimming often requires the use of an intermittent incremental protocol, whose step lengths are corner stones for the efficiency of the evaluation procedures. Purpose: To analyze changes in swimming kinematics and interlimb coordination behavior in 3 variants, with different step lengths, of an intermittent incremental protocol. Methods: Twenty-two male swimmers performed n × di variants of an intermittent and incremental protocol (n ≤ 7; d1 = 200 m, d2 = 300 m, and d3 = 400 m). Swimmers were videotaped in the sagittal plane for 2-dimensional kinematical analysis using a dualmedia setup. Video images were digitized with a motion-capture system. Parameters that were assessed included the stroke kinematics, the segmental and anatomical landmark kinematics, and interlimb coordination. Movement efficiency was also estimated. Results: There were no significant variations in any of the selected variables according to the step lengths. A high to very high relationship was observed between step lengths. The bias was much reduced and the 95%CI fairly tight. Conclusions: Since there were no meaningful differences between the 3 protocol variants, the 1 with shortest step length (ie, 200 m) should be adopted for logistical reasons.
- Energy cost and body centre of mass' 3D intracycle velocity variation in swimmingPublication . Figueiredo, Pedro; Barbosa, Tiago M.; Vilas-Boas, João Paulo; Fernandes, Ricardo J.The purpose of this study was to examine the relationship between the energy cost (C) and the 3D intracycle velocity variation (IVV; swimming direction—x, vertical—y and lateral—z axes) throughout the 200 m front crawl event. Ten international level swimmers performed a maximal 200 m front crawl swim followed by 50, 100 and 150 m bouts at the same pace as in the 200 m splits. Oxygen consumption was measured during the bouts and blood samples were collected before and after each one. The C was calculated for each 50 m lap as the ratio of the total energy expenditure (three energy pathways) to the distance. A respiratory snorkel and valve system with low hydrodynamic resistance was used to measure pulmonary ventilation and to collect breathing air samples. Two above water and four underwater cameras videotaped the swim bouts and thereafter APAS was used to assess the centre of mass IVV (x, y and z components). The increase in the C was significantly associated with the increase in the IVV in x for the first 50 m lap (R = −0.83, P < 0.01). It is concluded that the IVV relationship with C in a competitive event does not present the direct relationship found in the literature, revealing a great specificity, which suggests that the relation between these two parameters could not be used as a performance predictor in competitive events.