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- Análise longitudinal da performance em natação pura desportiva: abordagem exploratóriaPublication . Costa, M.J.; Bragada, José A.; Marinho, D.A.; Reis, Victor M.; Silva, A.J.; Barbosa, Tiago M.O estudo teve como objectivo analisar a estabilidade da performance na prova de 400m livres ao longo da carreira desportiva. Foram analisados 45 nadadores masculinos, durante sete épocas consecutivas (desde a categoria de Infantil B até Sénior). A performance foi analisada com recurso ao melhor tempo em cada categoria na prova de 400m Livres em piscina curta. Foi efectuada a análise da estabilidade das médias, pela observação dos quartis ao longo da carreira desportiva, assim como a tendência central (média) e respectiva dispersão (um desvio-padrão). Foi ainda analisada a variação entre valores médios com recurso à ANOVA medidas repetidas e respectivo post-hoc teste (Bonferroni). Analisou-se ainda a estabilidade normativa pela auto-correlação entre as sete categorias (Pearson). Foi calculado o Kappa de Cohen (K) com um intervalo de confiança de 95%. Para todos os procedimentos estatísticos foi utilizado o programa informático SPSS 13,0 à excepção do K, o qual foi calculado através do programa estatístico Longitudinal Data Analysis. Foram verificadas diferenças significativas entre os valores médios de performance entre todas as categorias. Os valores de auto-correlação variaram entre o moderado e o elevado ao longo da carreira desportiva. Constata-se que na passagem de Juvenil B para A, a estabilidade torna-se elevada (>0,60). O valor de K, expressando a estabilidade ao longo de toda a carreira desportiva, é baixo (K = 0.327 ± 0,046). Em síntese, a predição do nível competitivo na categoria sénior com base na performance nas categorias de formação é reduzido. Todavia, a passagem de Juvenil B para A parece ser um momento marcante, onde a capacidade preditiva aumenta de forma acentuada.
- Net heart rate to prescribe physical activity in middle-aged to older active adultsPublication . Bragada, José A.; Magalhães, Pedro; Vasques, Catarina; Barbosa, Tiago M.; Lopes, Vitor P.This study had a twofold purpose: i) to develop a regression equation to estimate metabolic equivalent (MET) in walk/run by heart rate increment above rest (NetHR), and; ii) to determine NetHR thresholds for light, moderate, and vigorous physical activity (PA), from middle aged to elderly. Sample 1 (prediction sample) comprised 39 subjects (19 male and 20 female), with 58.2 ± 11.0 years old. Sample 2 (validation sample) comprised 40 subjects (18 male and 22 female) with 63.3 ± 7.0 years old. Each participant did the following activities in sequence, a 15min rest period in supine position, walk at 3km/h, walk at 4.5km/h, and walk at 6km/h, for 6 min at each walk velocity interval. The oxygen up-take (VO2) and heart rate (HR) were continuously and simultaneously assessed. A hierarchical linear model was used to analyze the relationship between metabolic equivalent (MET) and NetHR. The regression equation for MET prediction was: MET = 1.265780 + 0.109479 NetHR. The NetHR thresholds (upper limit) for light, moderate and vigorous PA were 16 and 35 and 70 bpm, respectively. NetHR is a practical, valid and non-invasive method to prescribe physical activity, taking in account individual characteristics (HR at rest combined with NetHR) in middle-aged to older adults.
- A eficiência propulsiva e a performance em nadadores não expertsPublication . Barbosa, Tiago M.; Lima, V.; Mejias, J. Erik; Costa, M.J.; Marinho, D.A.; Garrido, Nuno D.; Silva, A.J.; Bragada, José A.O estudo da eficiência propulsiva é um dos assuntos mais interessantes para os investigadores em natação pura desportiva, já que apresenta uma relação directa no comportamento biofísico do nadador e na sua performance. Apesar de ser uma variável que tem sido bastante estudada em nadadores de elevado nível competitivo, não há nenhuma investigação sobre esta temática em jovens nadadores não experts. Assim, o objectivo deste estudo foi: (i) estimar a eficiência propulsiva em nadadores não experts; (ii) identificar os factores biomecânicos e antropométricos que estão associados à eficiência propulsiva e; (iii) identificar a associação entre a eficiência propulsiva e a performance. Vinte e oito nadadores não experts, praticantes regulares de natação numa Escola Municipal participaram neste estudo. Foram avaliados a eficiência propulsiva, parâmetros biomecânicos, antropométricos e a performance de nado. Os principais resultados encontrados mostram que a eficiência propulsiva de nadadores não experts é inferior à descrita na literatura para nadadores de outros níveis competitivos e que não há diferenças significativas entre os dois sexos. Foi também verificado que vários parâmetros biomecânicos, antropométricos, assim como, a performance estão associados com a eficiência propulsiva.
- Continuos incremental field test to estimate velocity and maximal oxygen consumption in non-expert runnersPublication . Bragada, José A.; Moreno, Rodolfo; Barbosa, Tiago M.Parameters such as a maximal oxygen uptake (VO2max) and velocity at which VO2max occurs (VelVO2max) are often used to training control purposes to enhance runner’s performance. This study had two purposes: (i) determine the relationship between VelVO2max obtained in continuous incremental filed test (CIFT) and VelVO2max determined on a treadmill in a laboratory; and (II) verify if it is possible to estimate the VO2max based on CIFT velocity
- Actigraph calibration in obese/overweight and type 2 Diabetes Mellitus middle-aged to old adult patientsPublication . Lopes, Vitor P.; Magalhães, Pedro; Bragada, José A.; Vasques, CatarinaBackground: Several methods exist to asses and control physical intensity levels of subjects engaged in physical activities programs, accelerometry is a method that could be easily used in the field. The purposes were: to calibrate Actigraph in middle-aged to old obese/overweight and DM2 adult patients; and to determine the threshold counts for sedentary, light, moderate, and vigorous physical activity (PA). Methods: Sample comprise 26 participants (62.6 ± 6.5 years of age) of both gender. Counts and VO2 were simultaneously assessed during: resting, seating, standing, walking at 2.5 km·h–1, 5 km·h–1, and 6 km·h–1. A hierarchical linear model was used to derive a regression equation between MET and counts. Receiver operating characteristics (ROC) analysis was used to define thresholds for PA levels. Results: The regression equation was: MET = 1.388400490262 + 0.001312683420044 (counts·min–1), r = .867. The threshold counts for sedentary-light, light-moderate and moderate-vigorous PA were: 200, 1240, 2400 counts·min–1 respectively. Conclusion: The Actigraph is a valid and useful device for the assessment of the amount of time spent in each PA intensity levels in obese/overweight and DM2 middle-aged to old adult patients.
- Aerobic performance and morphological modifications after a 4 months's physical activity training program in elderly womenPublication . Monteiro, A.M.; Carvalho, Joana; Mota, Paula; Bragada, José A.Research clearly shows that physical activity (PA) is an important factor to develop and maintain good health and adequate body functions in older people. In this context, the purpose of this study was to determine aerobic performance and morphological modifications after a 4 month physical activity program (PAP) in elderly. METHODS Forty subjects divided in two groups (control, n=20; and experimental, n=20) were evaluated twice, at the beginning and after a 4-month-activity program period. This program called “+ age + health” consists of 3 week sessions of one hour each, based on walking and aerobic exercises. The control group had, at its first evaluation, the followings characteristics: average body mass 68kg±15, 28±5 BMI, 37%±5 body fat, 2.2kg±0.4 bone mass, 42%±9 lean body mass and did 129 repetitions ± 46 on a 2-Minute Step Test (2MST). The assessment of anthropometric and morphological variables was measured through an electrical bioimpedance scale (TANITA - BC 545). Aerobic endurance was evaluated from a 2MST.RESULTS In the control group only the percentage of body fat changed significantly, and increased over time. In the experimental group we found a positive relationship between PAP and the majority of morphological variables. The percentage of variation changed in: body fat (-4.3%±7.6, p=0.014), bone mass (2.4%±3.1, p=0.004) and 2MST (33.6%±63.1, p=0.023). In the remaining variables there were no significant modifications. The significant modification in 2MST after the activity period means that the aerobic performance can be improved in elderly, and attenuates the negative effects of age. Moreover, the benefits of PAP can be seen by positive alterations registered in lean body mass and in the percentage of body fat.
- Aerobic performance and morphological modifications after a 4 months's physical activity training program in elderly womenPublication . Monteiro, A.M.; Carvalho, Joana; Mota, Paula; Bragada, José A.Research clearly shows that physical activity (PA) is an important factor to develop and maintain good health and adequate body functions in older people. In this context, the purpose of this study was to determine aerobic performance and morphological modifications after a 4 month physical activity program (PAP) in Forty subjects divided in two groups (control, n=20; and experimental, n=20) were evaluated twice, at the beginning and after a 4-month-activity program period. This program called “+ age + health” consists of 3 week ses- sions of one hour each, based on walking and aerobic exercises. The control group had, at its first evaluation, the fol- lowings characteristics: average body mass 68kg±15, 28±5 BMI, 37%±5 body fat, 2.2kg±0.4 bone mass, 42%±9 lean body mass and did 129 repetitions ± 46 on a 2-Minute Step Test (2MST). The assessment of anthropometric and mor- phological variables was measured through an electrical bioimpedance scale (TANITA - BC 545). Aerobic endurance was evaluated from a 2MST
- Calibration of MTI actigraph in old obese adultPublication . Lopes, Vitor P.; Magalhães, Pedro; Bragada, José A.The purpose was to derive a regression equation that estimatcs energy expenditure from accelerometer counts in oId obese adult. The sample comprised 14 oId obese or overweight adults (63±7 years).
- Longitudinal assessment of swimming performance in the 200 m freestyle eventPublication . Costa, M.J.; Bragada, José A.; Marinho, D.A.; Reis, Victor M.; Silva, A.J.; Barbosa, Tiago M.Several studies have been carried out in order to identify the factors that can predict swimming performance. However, all these studies only analyzed determinant factors in a single moment. It was not taken into account the longitudinal stability and changes, as a result of individual development, new training methods and technological sophistication.
- Estudo longitudinal do rendimento e de parâmetros da carga (interna e externa) em corredores de 3000mPublication . Bragada, José A.; Santos, Paulo Jorge Miranda; Maia, José A.R.O presente estudo teve como objectivo estudar, simultaneamente, as alterações no rendimento na prova de 3000m, em parâmetros fisiológicos considerados determinantes do rendimento desportiva (consumo máximo de oxigénio - VO2max, limiar anaeróbio - LAn, velocidade a que ocorre o VO2max - VelVO2max e economia de corrida - EC) e em parâmetros do processo de treino (volume de treino semanal total - VOLSEM, intensidade da corrida contínua - INTCC e percentagem de treino intervalado relativamente ao volume total - PERCTI), num grupo de corredores de MF, ao longo de duas épocas desportivas.