The evaluation of swimming technique is one of the main aspects to be considered in any training program, with biomechanics being an important source of knowledge. It was our objective to characterize the biomechanical parameters (SL and SF) relating them to the swimming velocity (v) at different intensities and to analyze within each swimming stroke cycle the intra-cyclic velocity variation (IVV) in a group of motor disabled swimmers. Eight disabled male swimmers (25.83 ± 2.93 years old, 72.45 ± 9.26 kg body mass and 1.79 ± 0.11 m of height) of the following functional classes: S6 (n = 1), S8 (n = 2) and S9 (n = 5) participated in this study. Swimmers were evaluated in the kinematic parameters v, stroke frequency (SF) and stroke length (SL) along with an incremental protocol of 6 x 200 m in the the crawl stroke. Data were registered in each step at the distances of 100 and 175 m. With increasing velocity, the mean values of SL decreased while the mean values of SF increased. To achieve higher swimming velocities, swimmers compensated the lack of the propulsive segment increasing SF to increase swimming speed. For the mean values of IVV at 100m distance, a decrease between the first and second levels, followed by a tendency to stabilize from the 2nd to the 6th level is presented. For the 175 m distance, there was a decrease in IVV with an increase in swimming velocity. Stroke frequency is directly related to the magnitude of IVV, which directly influences swimming performance.

INTRODUÇÃO: Tradicionalmente, os estudos da cinética do consumo de oxigênio são conduzidos a intensidades de exercício baixas, bem distintas daquelas em que o desempenho desportivo acontece. OBJETIVO: Considerando que a magnitude da cinética deste parâmetro fisiológico depende da intensidade a que o esforço é realizado, pretendeu-se com este trabalho comparar a cinética do consumo de oxigênio em 200 m crowl nadados a duas intensidades distintas: moderada e extrema. MÉTODOS: Dez nadadores do sexo masculino, de nível internacional, realizaram dois testes separados: (i) protocolo progressivo e intervalado de7 x200 m, com 30 segundos de intervalo e incrementos de 0,05 m.s-1 para determinação do patamar correspondente ao limiar anaeróbio; e (ii) 200 m à máxima velocidade. Em ambos, realizou-se uma recolha contínua de gases expirados respiração-a-respiração. RESULTADOS: Diferenças significativas foram obtidas na amplitude e constante temporal determinadas nos 200 m nadados à intensidade extrema e moderada, respectivamente: 38,53 ± 5,30 versus 26,32 ± 9,73 ml. kg-1.min-1 e 13,21 ± 5,86 versus 18,89 ± 6,53 s (p ≤ 0,05). Não foram encontradas diferenças no atraso temporal (9,47 ± 6,42 versus 12,36 ± 6,62 s (p ≤ 0,05), à intensidade extrema e moderada, respectivamente. O atraso temporal correlacionou-se negativamente com a constante temporal à intensidade moderada (r = -0,74, p ≤ 0,05). CONCLUSÕES: Ambas as intensidades estudadas foram bem descritas por aproximações mono-exponenciais, tendo-se verificado diferenças significativas entre as mesmas no que concerne à amplitude e constante temporal.

INTRODUCTION: Traditionally, studies regarding oxygen consumption kinetics are conducted at lower intensities, very different from those in which the sports performance occurs. OBJECTIVE: Knowing that the magnitude of this physiological parameter depends on the intensity in which the effort occurs, it was intended with this study compare the oxygen consumption kinetics in the 200 m front crawl at two different intensities: moderate and extreme. METHODS: Ten international male level swimmers two separate tests by 24h: (i) progressive and intermittent protocol of 7 x 200 m, with 30 seconds intervals and with increments of 0.05m.s-1, to determine the anaerobic threshold correspondent step; and, (ii) 200 m at maximal velocity: in both expiratory gases were continuously collected breath-by-breath. RESULTS: Significant differences were obtained between amplitude and time constant determine in the 200 m at extreme and moderate intensities, respectively (38,53 ± 5,30 ml. kg-1.min-1 versus 26,32 ± 9,73 ml. kg-1.min-1 e 13,21 ± 5,86 s versus 18,89 ± 6,53 s (p ≤ 0,05). No differences were found in time delay (9,47 ± 6,42 s versus 12,36 ± 6,62 s, at extreme and moderate intensity, respectively (p ≤ 0.05). A negative correlation between time delay and time constant at the moderate intensity was reported (r = - 0,74, p ≤ 0,05). CONCLUSIONS: Both intensities were well described by double-exponential fittings, and there were significant differences between them in terms of amplitude and time constant.

O presente estudo discute a necessidade de se repensar a abordagem tradicional do ensino da Natação. A Natação, como disciplina desportiva, é uma actividade multidisciplinar, a qual pode ser extremamente rica ao nível da experimentação motora e variação de práticas desportivas aquáticas. É neste contexto que se confronta a realidade actual do ensino da Natação com uma realidade mais desejada, de âmbito multidisciplinar. Na sequência da análise efectuada, enfatizou-se, sobretudo, a orientação e adequação dos conteúdos de ensino da Natação para crianças e jovens, população específica nas suas características e necessidades de desenvolvimento. No sentido de se atender a este grupo especifico, após se ter salientado a pertinência da multidisciplinaridade, efectua-se uma proposta de abordagem de habilidades motoras aquáticas básicas envolvendo a natação pura, o pólo aquático, a natação sincronizada e os saltos para a água, considerando a fase de ensino inicial da Natação - a Adaptação ao Meio. Esta proposta visa divulgar a implementação do ensino multidisciplinar da Natação, o qual se considera ser cada vez mais urgente, particularmente pela pouca expressão que as modalidades aquáticas tradicionalmente consideradas como satélites da Natação - pólo aquático, natação sincronizada e saltos para a água - têm tido no contexto desportivo nacional.

The present study proposes a new multidisciplinary approach related to teaching in swimming. Swimming is an interdisciplinary physical activity, which can be truly important at the level of the motor learning and experimentation in aquatic activities. In the present manuscript, it was compared the present reality of teaching in Swimming with a new perspective, this one with a multidisciplinary scope. Following the referred analysis, it was presented a discussion about the orientation and adequacy of the contents of the Swimming curriculum for children and youngsters, which are populations with specific characteristics and development necessities. In this sense, after stating the relevance of a multidisciplinary perspective, it was proposed a new approach for basic aquatic motor skills acquisition based on four disciplines: swimming, water polo, synchronised swimming and platform diving. This was made taking into account the initial stage of swimming teaching, i.e., aquatic readiness. This proposal aims mainly at implementing the teaching of Swimming at a multidisciplinary point of view that, in our opinion, is urgent, namely due to the small expression that the aquatic modalities traditionally considered as swimming satellites (water polo, synchronised swimming and platform diving) have in the Portuguese sports context.