PurposeThere is physiological and biomechanical evidence suggesting a possible advantage of using poles in walking training programs. The purpose of this proof-of-concept study was to test the hypothesis that untrained elderly training Nordic walking for eight weeks will show higher improvements on the functional mobility, quality of life and postural balance than that training without poles; more likely to occur in self-selected walking speed (primary outcome), and the locomotor rehabilitation index than the quality of life, the static balance and the dynamic stability. It was a two-arm randomized sample- and load-controlled study.MethodsThirty-three untrained older people were randomly assigned into Nordic walking (n = 16, age: 64.6±4.1 years old) and free walking (n = 17, age: 68.6±3.9 years old) training groups.ResultsImprovements in the self-selected walking speed (primary outcome, p = 0.011, ES = 0.42 95%CI -0.31 to 1.16), locomotor rehabilitation index (p = 0.013, ES = 0.36; (95%CI -0.39 to 1.10), quality of life (p<0.05), static balance (p<0.05) and dynamic variability (p<0.05) were found in both groups.ConclusionsThe hypothesis was not supported, our findings indicated that after 8 weeks, the Nordic walking training did not result in greater improvements than free walking training for the primary outcome (self-selected walking speed) and most of the secondary outcomes (including locomotor rehabilitation index, static balance, dynamic stability, and psychological and social participation domains of quality of life).Trial registrationClinicalTrials.gov NCT03096964.

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This study was designed to compare surface electromyographic (sEMG) signal and force production during maximal voluntary isometric contractions (MVCs) in water and on dry land. The reproducibility of sEMG and isometric force measurements between water and dry land environments was also assessed. Nine women performed MVC for elbow flexion and extension, hip flexion, and extension against identical fixed resistance in both environments. The sEMG signal from biceps brachii, triceps brachii, rectus femoris, and biceps femoris was recorded with waterproof adhesives placed over each electrode. The sEMG and force production showed no significant difference between water and dry land, except for HEX (p = 0.035). In addition, intraclass correlation coefficient values were significant and ranged from moderate to high (0.66-0.96) for sEMG and force production between environments. These results showed that the environment did not influence the sEMG and force in MVC.

Exercitar-se na água é uma prática constatada há vários séculos, embora seja recente sua realização de forma sistemática e planejada. A literatura científica é ampla no estudo dos efeitos do treinamento aeróbico aquático, tendo investigado diferentes modalidades. Nas últimas décadas têm ganhado relevância os estudos que avaliam treinamentos aquáticos de caráter de força e sua melhora no sistema neuromuscular. Contudo estes trabalhos apresentam metodologias de prescrição muito diferentes, dificultando sua comparação. Assim, o objetivo desta revisão é elucidar aspectos metodológicos para prescrição de exercícios de força no meio aquático. Este artigo tem caráter narrativo e para a localização e aquisição dos estudos foram consultadas as bases de dados eletrônicas SCOPUS, PUBMED, SCIELO e MEDLINE, realizando-se buscas de artigos publicados entre os anos 1980 e 2016, com os seguintes descritores: hidroginástica, treinamento de força aquático e corrida em piscina funda. Os resultados demonstraram que os primeiros estudos publicados mundialmente relacionados a este tema datam do final dos anos 90. Estes seguiam metodologias de treinamento que buscavam reproduzir o modelo aplicado no meio terrestre, ou seja, utilizando número de repetições e número de séries. Por outro lado, os estudos mais recentes têm proposto a utilização da velocidade máxima e o tempo de execução para se alcançar a rota metabólica adequada (sistemas fosfocreatina e glicolítico). Assim, os trabalhos demonstram que o treinamento de força no meio aquático têm proporcionado resultados satisfatórios em variáveis neuromusculares e morfológicas. Ainda, a prescrição de um treinamento de força neste meio, visando a rota metabólica adequada, utilizando o tempo de execução e a máxima velocidade, parece ser a forma mais eficiente de se alcançar objetivos relacionados ao treinamento de força.

This study aimed to investigate the acute effects of two strength-training protocols on the neuromuscular and cardiorespiratory responses during endurance exercise. Thirteen young males (23.2 ± 1.6 years old) participated in this study. The hypertrophic strength-training protocol was composed of 6 sets of 8 squats at 75% of maximal dynamic strength. The plyometric strength-training protocol was composed of 6 sets of 8 jumps performed with the body weight as the workload. Endurance exercise was performed on a cycle ergometer at a power corresponding to the second ventilatory threshold until exhaustion. Before and after each protocol, a maximal voluntary contraction was performed, and the rate of force development and electromyographic parameters were assessed. After the hypertrophic strength-training and plyometric strength-training protocol, significant decreases were observed in the maximal voluntary contraction and rate of force development, whereas no changes were observed in the electromyographic parameters. Oxygen uptake and a heart rate during endurance exercise were not significantly different among the protocols. However, the time-to-exhaustion was significantly higher during endurance exercise alone than when performed after hypertrophic strength-training or plyometric strength-training (p <0.05). These results suggest that endurance performance may be impaired when preceded by strength-training, with no oxygen uptake or heart rate changes during the exercise.