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- Effect of glide on neuromuscular adaptation in breaststroke swimming: a case study of an elite swimmerPublication . Conceição, Ana; Frédéric, Puel; Louro, Hugo; Morgado, Sónia; Seifert, LudovicThe aim of this case study was to examine the upper and lower limbs muscular responses of one elite breaststroke swimmer at three different glide and speed conditions, to understand how strength and condition could be optimized during training. Surface electromyograms (sEMG) were collected in biceps brachii (BB), biceps femoris (BF), deltoid anterior (DA), gastrocnemius medialis (GM), pectoralis major (PM) rectus femoris (RF), tibialis anterior (TA), and tríceps brachii (TB) during 18 x 25 m breaststroke trials performed at three different glide( normal, maximal, minimal) and speed (70, 80 and 90% of maximal speed) conditions. Each trial required an individually imposed swimming speed corresponding to 70, 80 and 90% of the swimmer maximal speed and a specific glide condition: minimal glide, normal glide and maximal glide. In maximal glide, higher participation of TB and DA and TA, RF, and GM muscles. In normal glide, a significant higher participation of all the muscles occurred, except for GM. In minimal glide, a significant higher participation of all the muscles occurred, except for the PM. We have also found that swimming at 90% of maximal speed led to significant higher use of the BB and PM muscles, for the upper limbs and BF and TA muscles for the lower limbs. In conclusion, the swimmer recruited different muscles as increasing his swimming speed and when gliding differently than normally. It suggested that strength and condition should be trained for various swimming speeds associated to various conditions of glide to ensure behavioral adaptability in competition.
- Angiotensin-converting enzyme genotype affects skeletal muscle strength in elite athletesPublication . Costa, Aldo; Silva, António; Garrido, Nuno; Louro, Hugo; Marinho, Daniel; Marques, Mário; Breitenfeld, LuisaPrevious studies have associated angiotensin-converting enzyme (ACE) D allele with variability in the skeletal muscle baseline strength, though conclusions have been inconsistent across investigations. The purpose of this study was to examine the possible association between ACE genotype and skeletal muscle baseline strength in elite male and female athletes involved in different event expertise. A group of 58 elite athletes, designated as Olympic candidates, were studied: 35 swimmers (19 males and 16 females, 18.8 ± 3.2 years) and 23 triathletes (15 males and 8 females, 18.7 ± 3.0 years). The athletes were classified as: short (≤ 200m) and middle (400m to 1500m) distance athletes, respectively. For each subject the grip strength in both hands was measure using an adjustable mechanical hand dynamometer. The maximum height in both squat jump (SJ) and counter movement jump (CMJ) were also assessed, using a trigonometric carpet (Ergojump Digitime 1000; Digitest, Jyvaskyla, Finland). DNA extraction was obtained with Chelex 100® and genotype determination by PCR-RFLP methods. Both males and females showed significantly higher right grip strength in D allele carriers compared to II homozygote’s. We found that allelic frequency differs significantly by event distance specialization in both genders (p < 0.05). In fact, sprinter D allele carriers showed the superior scores in nearly all strength measurements (p < 0.05), in both genders. Among endurance athletes, the results also demonstrated that female D allele carriers exhibited the higher performance right grip and CMJ scores (p < 0.05). In conclusion, the ACE D allele seems associated with skeletal muscle baseline strength in elite athletes, being easily identified in females.
- Análise da qualidade do sistema de observação do comportamento técnico de bruçosPublication . Matos, Telmo; Silva, António; Conceição, Ana; Freitas, João; Campaniço, Jorge; Louro, HugoO presente estudo teve como objetivo o processo de construção e validação de um instrumento de observação. Neste contexto, centrámos a análise num requisito fundamental – a validade e fiabilidade do instrumento, instrumento este que servirá de base ao registo dos comportamentos observados durante a execução de vinte ciclos gestuais na técnica de bruços. O instrumento foi composto por um sistema de Formatos de Campo (Oliveira, Campaniço & Anguera, 2001), com base em referências da metodologia observacional e modelos biomecânicos da Natação (Colman & Persyn, 1993; Silva & Alves, 2000; Louro, Garrido, Ferraz, Marinho, Conceição, Tolentino, Barbosa & Silva, 2009), dando especial evidência a cinco critérios taxionómicos que agregam, na forma de códigos alfa-numéricos, a informação decisiva para descrever comportamentos que definem a técnica de bruços. Para garantir o rigor e objectividade do instrumento, foi efectuada a análise à qualidade e validade do instrumento recorrendo ao Índice de Kappa (Anguera, 1993; Blanco 1993, 1997), com base nos registos de cinco observadores treinados (inter-observadores, 96.9%) e, para efeitos de precisão, de mais um perito (intra-observador, 97.8%). Como conclusão, é possível apurar que a valência deste instrumento qualitativo é bem evidente pelos elevados valores de concordância, tornando-se um instrumento adequado para observar os comportamentos técnicos dos nadadores em bruços. - The aim of this study was the process of construction and validation of an observation instrument. In this context, we focused the analysis on a fundamental requirement - the validity and reliability of the instrument. This instrument will serve as basis for the registration of behaviors observed during the execution of twenty gestural cycles of the breaststroke technique. The instrument consisted of a Field Formats system (Oliveira, Campaniço & Anguera, 2001), based on references of the observational methodology and Swimming biomechanical models (Persyn & Colman, 1993; Silva & Alves, 2000; Louro, Garrido, Ferraz, Marinho, Conceição, Tolentino, Barbosa & Silva, 2009), giving special emphasis to five taxonomic criteria that aggregate, in the form of alpha-numeric codes, crucial information to describe behaviors that define the breaststroke technique. To ensure the instrument’s accuracy and objectivity, an analysis of the instrument’s quality and validity was made, using the Kappa Index (Anguera, 1993; Blanco 1993, 1997). This analysis was based on records of five trained observers (inter-observer, 96.9%) and, for accuracy purposes, another expert (intraobserver, 97.8%). In conclusion, it is possible to determine that, given the high reliability values, the validity of this qualitative instrument is evident, making it a suitable instrument to observe the technical behavior in breaststroke swimmers.
- Relação entre expectativas e perceção de treinadores futebol sobre o conteúdo da instrução em competiçãoPublication . Santos, Fernando; Louro, Hugo; Lopes, Hélder; Rodrigues, JoséA presente investigação pretende estudar as expectativas e a perceção de treinadores sobre o conteúdo da instrução em competição e verificar de que forma se relacionam. Foram questionados antes e no fim da competição, 4 treinadores de futebol jovem que orientavam equipas que disputavam os campeonatos nacionais de Portugal. Utilizamos para o efeito questionários adaptados e validados para este estudo (Mesquita, Isidro, & Rosado, 2010; Hill & Hill, 2009; Tuckman, Manual of Research in Education, 2002). Os resultados demonstram que os treinadores têm expectativas e auto perceção de emissão durante a competição de instrução com conteúdo psicológico e tático. Apesar de terem sido registadas algumas correlações entre as variáveis estudadas, verifica-se pouca congruência ao nível do pensamento do treinador.
- Neuromuscular Fatigue during 200 M BreaststrokePublication . Conceição, Ana; Silva, António; Barbosa, Tiago; Karsai, Istvan; Louro, HugoThe aims of this study were: i) to analyze activation patterns of four upper limb muscles (duration of the active and non-active phase) in each lap of 200m breaststroke, ii) quantify neuromuscular fatigue, with kinematics and physiologic assessment. Surface electromyogram was collected for the biceps brachii, deltoid anterior, pectoralis major and triceps brachii of nine male swimmers performing a maximal 200m breaststroke trial. Swimming speed, SL, SR, SI decreased from the 1st to the 3rd lap. SR increased on the 4th lap (35.91 ± 2.99 stroke·min-1). Peak blood lactate was 13.02 ± 1.72 mmol·l-1 three minutes after the maximal trial. The EMG average rectified value (ARV) increased at the end of the race for all selected muscles, but the deltoid anterior and pectoralis major in the 1st lap and for biceps brachii, deltoid anterior and triceps brachii in the 4th lap. The mean frequency of the power spectral density (MNF) decreased at the 4th lap for all muscles. These findings suggest the occurrence of fatigue at the beginning of the 2nd lap in the 200m breaststroke trial, characterized by changes in kinematic parameters and selective changes in upper limb muscle action. There was a trend towards a non-linear fatigue state.
- Stability of behaviour patterns in the 200m breaststrokePublication . Louro, Hugo; Silva, António; Campaniço, Jorge; Matos, Telmo; Conceição, AnaThe aim of this study was to analyse the stability of the breaststroke technique in five elite swimmers in a 200m event using a qualitative analysis. The codification of the behaviour of each swimmer during the execution of 20 cycles was achieved using an ad hoc observational instrument comprised of a system of categories and field formats to detect the behavioural patterns (T-patterns); software was used for identifying the technical behaviour of stable structures. The results showed that the stability behaviour varied depending on the swimmer, as the variations of codes in each round produced distinct configurations to determine the differences between cycles for the same swimmer. It was concluded that the instrument used in this study plays an important role through the existence of stable behaviour in the breaststroke technique. It was also concluded that there are distinct patterns and behaviours between swimmers during each lap of the race.
- Occlusion technique in swimming: a training method to improve exchange block time in swimming relaysPublication . Conceição, Ana; Costa, Aldo M; Silva, António J; Sobreiro, Pedro; Louro, HugoSwimming relay events have the concern regarding a good start is shared between the incoming and outgoing swimmers. The aim of this study was to evaluate changes in exchange block time (eBT) for swimming relay events as a result of a four-week training program using the occlusion technique. MeThodS: Twenty-eight national swimmers, 12 males (age: 17±1.83 years) and 16 females (age: 19.94±5.65 years) participated in this study. Subjects were required to undergo a training program on visual perception in relay swimming over the course of four weeks; they watched videos corresponding to the last movements of a swimmer during a 4×100m freestyle relay event. The videos were presented with temporal occlusion corresponding to predetermined approaching distances (7.5 m, 5.0 m, and 2.5 m). Swimmers were required to simulate a typical position for exiting the block and to estimate the time-to-contact of the incoming swimmer. The eBT was collected during a real 4×100-m freestyle competition before and after the application of the training program. RESULTS: Female swimmers showed a decreased in EBT, with an improvement of 1.42%, despite there not being a signifcant difference (p=0.68). The male swimmers had a higher improvement in eBT after the training, with a decrease of 13.34% (p=0.68). coNcluSioNS: Visual perception practice using video occlusion techniques seems to have a positive effect. on eBT in swimming relay events, particularly in female swimmers
- Strategy operationalization in a Taekwondo FederationPublication . Sobreiro, Pedro; Sousa, José; Louro, Hugo; Conceição, Ana
- Análise da percepção visual nas rendições em natação pura desportivaPublication . Fonseca, Andreia; Louro, Hugo; Conceição, AnaNo âmbito das estafetas em NPD existe uma escassez de investigação sobre as rendições. Um dos desafios é minimizar o tempo de saída do atleta do bloco com o outro que toca na parede, focamo-nos assim no estudo das habilidades visuais nas rendições, verificando a ação motora através da aplicação de um programa de treino de perceção visual nas rendições. O objetivo é verificarmos em que medida é que através da utilização de um programa de treino, a técnica da rendição nas estafetas traz melhorias no tempo de reação. A amostra foi composta por 28 Rev UIIPS. 2019; 7(2): 181-193 182 nadadores com idade 16.36±4.49 anos. Nos resultados sobre a diferença de tempos, as nadadoras em comparação com os nadadores apresentaram melhorias para cada distância de oclusão e sobre a diferença do tempo de reação, as nadadoras apresentaram um efeito positivo no TR após, no entanto os nadadores apresentaram melhorias maiores no TR após a competição.
- Neuromuscular and motor patterns in breaststroke techniquePublication . Conceição, Ana; Silva, António; Barbosa, Tiago; Campaniço, Jorge; Louro, HugoAbstract – Te aim of this study was to analyze the inter-temporal neuromuscular and motor patterns in breaststroke technique. Five national level male swimmers performed 200 m breaststroke at maximal effort. Electromyography data onbiceps brachii, deltoid anterior, pectoralis major and triceps brachiiwere analysed. Te relative duration of active and non-active phase and the average rectifed value for the neuromuscular patterns were recorded. Te swim bouts were videotaped in sagittal plane with a pair of cameras and the Teme software 5.0 was used toanalyse the detected patterns in each swimmer. Te neuromuscular pattern revealed that by the average rectifed value the biceps brachiiand triceps brachiiwere increased at the end of the test for swimmers 1 and 5, while biceps brachii, deltoid anteriorand pectoralis majorwere increased for swimmers 2 and 4. Different motor patterns between cycles, and between swimmers were observed.We found similarities between the swimmers, adjusting their style to the technical model. Te absence of a neuromuscular pattern for all swimmers could be related to different technical models used by each swimmer, as presented in the motor patterns. Tese fndings suggested that each swimmers adapted their own motor and neuromuscular pattern in a unique and distinct way