Artigos em revistas internacionais - ESDRM
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- Osteogenic index of step exercise depending on choreographic movements, session duration, and stepping ratePublication . Santos-Rocha, Rita; Oliveira, Carla; Veloso, António PrietoStep exercise has been promoted as a low impact physical activity recommended for the improvement of cardiorespiratory and muscular fitness. This recreational activity might also be recommended to improve bone health since mechanical load plays an important role in the normal development of the skeleton.
- Comparative study of plantar pressure during step exercise in different floor conditionsPublication . Santos-Rocha, Rita; Veloso, António PrietoMechanical load has been estimated during step exercise based on ground reaction force (GRF) obtained by force platforms. It is not yet accurately known whether these measures reflect foot contact forces once the latter depend on footwear and are potentially modified by the compliant properties of the step bench. The aim of the study was to compare maximal and mean plantar pressure (PP), and maximal GRF obtained by pressure insoles after performing seven movements both over two metal force platforms and over the step bench. Fifteen step-experienced females performed the movements at the cadences of 130 and 140 beats per minute. PP and GRF (estimated from PP) obtained for each floor condition were compared. Maximal PP ranged from 29.27 +/- 9.94 to 47.07 +/- 12.88 N/cm2 as for metal platforms, and from 28.20 +/- 9.32 to 43.00 +/- 13.80 N/cm2 as for the step bench. Mean PP ranged from 11.09 +/- 1.62 to 14.32 +/- 2.06 N/cm2 (platforms) and from 10.71 +/- 1.54 to 14.22 +/- 1.77 N/cm2 (step bench). GRF (normalized body weight) ranged from 1.43 +/- 0.14 to 2.41 +/- 0.24 BW (platforms) and from 1.38 +/- 0.14 to 2.36 +/- 0.19 BW (step bench). No significant statistical differences were obtained for most of the comparisons between the two conditions tested. The results suggest that metal force platform surfaces are suitable to assess mechanical load during this physical activity. The forces applied to the foot are similar to the softer step bench and the hard force platform surface. This may reflect the ability of the performers to adapt their movement patterns to normalize the impact forces in different floor conditions.
- Comportamento pedagógico dos instrutores de aulas de fitness de localizadaPublication . Franco, Susana; Rodrigues, José; Castañer i Balcells, MartaEste estudo teve como objetivo realizar uma aplicação piloto do novo instrumento desenvolvido, Sistema de Observação do Comportamento dos Instrutores de Fitness – Aulas de Grupo (SOCIF), pretendendo-se identifi car e descrever quais as tendências comportamentais dos instrutores de fi tness nas aulas de grupo, designadamente de localizada. Materiais e Métodos: Foram observadas sessões de localizada, com conteúdo de treino de resistência muscular. Foi efetuado o registro da duração dos comportamentos, através do instrumento SOCIF. Resultados: Foram encontrados valores excelentes de fi delidade intra-observador. Discussão: Verifi cou-se que: quando confrontados os resultados deste estudo com os de outros estudos, independente do contexto, os dois principais comportamentos dos professores, treinadores ou instrutores são a informação e/ou observação, parecendo que os comportamentos restantes apresentam variações em termos de ocorrência; existem alguns comportamentos que os sujeitos nunca manifestaram; os comportamentos positivos predominam em relação aos negativos; as instrutoras utilizam comportamentos que são importantes como estratégias pedagógicas para reter os alunos à prática de exercício, quais sejam, a Afetividade positiva, avaliação positiva, pressão e conversas com alunos. Os comportamentos evidenciam uma variação na sua ocorrência, de sujeito para sujeito. Os comportamentos parecem mudar a sua ocorrência de acordo com as fases da aula. Os comportamentos aparentam ser infl uenciados pela posição de realização dos exercícios. As instrutoras, durante a aula, passam a maioria do seu tempo a realizar exercício físico.Introduction: The aim of this pilot study is to make an application of the new developed instrument Fitness Instructors’ Behaviour Observation System – Group Classes (SOCIF), and to describe which, in Resistance Training classes, the behaviour instructor’s tendencies are. Materials and Methods:There were observed Resistance Training sessions, in group classes, with the content of resistance strength. We registered the behaviours duration through an observation system of the instructors (SOCIF). Results: It was guaranteed excellent values of reliability intra -observer. Discussion: We have concluded that: When we confronted the results of this study with other studies, independently of the context, the two principal behaviours of the teachers, coaches or instructors are Information and/or observation, and the other behaviours present an variable occurrence; there are some behaviours that are never manifested by the instructors; the positive behaviours prevail in relation to the negatives; the instructors use behaviours that are important as pedagogical strategies to retain the participants to the exercise practice, such as positive affectivity, praise, hustle and conversation with participants. The behaviours seem to vary between instructors; the instructors’ behaviour seems to change their occurrence in agreement with the class’ phases. The instructors’ behaviour seems to be influenced by the position of the exercises. The instructors, during the class, spend most of the time in exercise.
- 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.
- Can the curriculum be used to estimate critical velocity in young competitive swimmers?Publication . Costa, Aldo; Silva, António; Louro, Hugo; Reis, Victor; Garrido, Nuno; Marques, Mário; Marinho, DanielThe aims of the present study were to assess critical velocity using the swimmer curriculum in front crawl events and to compare critical velocity to the velocity corresponding to a 4 mmol·l-1 of blood lactate concentration and to the velocity of a 30 min test. The sample included 24 high level male swimmers ranged between 14 and 16 years old. For each subject the critical velocity, the velocity corresponding to a 4 mmol·l-1 of blood lactate concentration and the mean velocity of a 30 min test were determined. The critical velocity was also estimated by considering the best performance of a swimmer over several distances based on the swimmer curriculum. Critical velocity including 100, 200 and 400 m events was not different from the velocity of 4 mmol·l-1 of blood lactate concentration. Critical velocity including all the swimmer events was not different from the velocity of a 30 min test. The assessment of critical velocity based upon the swimmer curriculum would therefore seem to be a good approach to determine the aerobic ability of a swimmer. The selection of the events to be included in critical velocity assessment must be a main concern in the evaluation of the swimmer.
- O Feedback Pedagógico em Instrutores de Ginástica Localizada com Diferentes Níveis de Experiência ProfissionalPublication . Simões, Vera; Franco, Susana; Rodrigues, JoséO presente estudo visa caracterizar o feedback pedagógico (feedback) emitido pelos instrutores de Fitness na actividade de Localizada; verificar se existem diferenças significativas, na frequência da emissão de feedbacks em instrutores com diferentes níveis de experiência profissional (instrutor de Fitness com ≤ 3 anos de experiência (grupo A); com > 3 a 5 anos de experiência (grupo B); com > 5 anos de experiência (grupo C)). Materiais e Métodos: a amostra foi constituída por 62 instrutores. Foram realizadas filmagens das aulas, sendo utilizado um sistema de observação composto por 7 dimensões e 24 categorias. Resultados: verificou-se existirem diferenças significativas relativamente à frequência de emissão de feedbacks/minuto, o grupo C foi o que mais emitiu e o grupo B o que menos emitiu. Quanto à emissão de feedback, tanto no grupo A como no grupo C, constatou-se que os tipos de feedback mais emitidos e menos emitidos foram os mesmos. A emissão no grupo B, foi semelhante ao dos grupos A e B, à excepção na categoria prescritivo positivo. Foram encontradas diferenças significativas entre os grupos nas categorias quinestésico e interrogativo. Discussão: foi o grupo B que mais se diferenciou dos outros grupos, no comportamento de feedback observado.
- Association between ACE D allele and elite short distance swimmingPublication . Costa, Aldo Matos; Silva, António José; Garrido, Nuno Domingos; Louro, Hugo; de Oliveira, Ricardo Jacó; Breitenfeld, LuizaThe influence of ACE gene on athletic performance has been widely explored, and most of the published data refers to an I/D polymorphism leading to the presence (I allele) or absence (D allele) of a 287-bp sequence in intron 16, determining ACE activity in serum and tissues. A higher I allele frequency has been reported among elite endurance athletes, while the D allele was more frequent among those engaged in more power-orientated sports. However, on competitive swimming, the reproducibility of such associations is controversial. We thus compared the ACE genotype of elite swimmers with that of non-elite swimming cohort and of healthy control subjects. We thus sought an association of the ACE genotype of elite swimmers with their competitive distance. 39 Portuguese Olympic swimming candidates were classified as: short (<200 m) and middle (400-1,500 m) distance swimmers, respectively. A group of 32 non-elite swimmers were studied and classified as well, and a control group (n = 100) was selected from the Portuguese population. Chelex 100 was used for DNA extraction and genotype was determined by PCR-RFLP methods. We found that ACE genotype distribution and allelic frequency differs significantly by event distance only among elite swimmers (P < or = 0.05). Moreover, the allelic frequency of the elite short distance swimmers differed significantly from that of the controls (P = 0.021). No associations were found between middle distance swimmers and controls. Our results seem to support an association between the D allele and elite short distance swimming.
- Analysis of kinematics of the lower limb during step exercisePublication . Santos-Rocha, RA; Veloso, António; Valamatos, M João; Machado, M Lourdes; André, Helô IsaThe motion of lower extremity joints is one of the mechanisms by which mechanical load is attenuated. The main purposes of this study were to characterize the motion of the right lower limb in a group of 18 women experienced in step exercise, when performing selected step patterns, and to investigate the differences that exist between four stepping rate conditions (125, 130, 135, and 140 beats per minute) and between four step patterns (basic step, knee lift, run step, and knee hop). The parameters explored were the range-of-movement and angular velocity of hip, knee, and ankle joints at initial contact and peak values. The four movement patterns analyzed presented different kinematical profiles, but no profiles were influenced by stepping rate. Stepping rate and step pattern had more effect on range of motion of ankle and knee joints, and on the angular velocity of knee and hip joints. To prevent injury, proper instruction should be provided in relation to foot placement on the step bench and on the ground.
- Stability of patterns of behavior in the butterfly technique of the elite swimmersPublication . Louro, Hugo; Silva, A.; Anguera, T.; Marinho, D.; Conceição, Ana; Campaniço, J.The purpose of this study was to find patterns in the butterfly swimming technique, with an adaptation of the Behavioral Observation System Tech. This, as an instrument for ad-hoc qualitative analysis, enables the study of the stability of the technical implementation. When used in the training of swimmers, analysis can reduce the variability of behavioral tuning swimming technique. Through the analysis of temporal patterns (T-pattern) and a sequence of five cycles running at hand maximum speed, the behavior of four technical Portuguese elite swimmers, with a record of 259 alphanumeric codes and a total of 160 configurations, were studied. The structure of the original instrument, based on a mixed system of categories and formats Field, can record technical features, observed during the execution of hand cycles. The validity was ensured through the index of intra-observer reliability (95%) and inter-observer accuracy (96%). To detect patterns in each swimmer, the Theme 5.0 software was used, which allowed to identify the stable structures of technical performance within a critical interval of time (p <0.05) - t-patterns. The patterns were different, adjusting to the characteristics of technical implementation of the swimmers. It was found that the swimmer can create settings with different levels of structure complexity, depending on the implementation of changes within the hand cycle. Variations of codes in each configuration obtained using the SOCTM, allowed determining the differences between swimmers. However, the records showed a clear behavioral similarity when comparing the result with a general pattern of the butterfly technique. The potential quality of this instrument seems to be important due to the patterns obtained from a temporal sequence.
- Análise comparativa da composição corporal e da distribuição de gordura corporal de sujeitos com doença das artérias coronárias envolvidos num programa de reabilitação cardíaca versus sedentáriosPublication . Pimenta, Nuno; Santa-Clara, Helena; Fragoso, IsabelO objectivo desta investigação foi analisar a composição corporal e a distribuição de gordura corporal de sujeitos com doença das artérias coronárias (DAC) envolvidos num programa estruturado de reabilitação cardíaca (PRC) e sujeitos com DAC que não participam em qualquer PRC. População e métodos: A amostra foi constituída por 62 sujeitos do sexo masculino, caucasianos, com DAC diagnosticada, oriundos de cada um de dois grupos estudados: grupo C/PRC (n=31) foi constituído por sujeitos que participavam na fase IV de um PRC há mais de um ano (idade: 58 + 10 anos); grupo S/PRC (n=31) foi constituído por sujeitos que não participavam em qualquer PRC (idade: 59 + 12 anos). Foi observada a composição corporal e distribuição de gordura corporal dos sujeitos da amostra, através da análise por Densitometria por Raio-X de Dupla Energia (DXA). Foram recolhidas medidas antropométricas.