Knee alignment with and without implements in leg press and squat exercises: a systematic review

Resistance training has been commonly used as a method of intervention in the rehabilitation of musculoskeletal injuries affecting the knee. Thus, the objective of this systematic review was to identify the methods employed with and without implements in leg press and squat exercises for the maintenance of knee alignment. The literature search was performed in the databases: PubMed, SciELO, and Lilacs. We used the descriptors "muscle strength" and "exercise" and their synonyms, available in the Health Sciences Descriptors (DeCS) and the Medical Subject Headings (MeSH), with the terms "valgus knee" and "varus knee". From the 1,117 articles found, eight studies were considered for the review. The included studies had samples composed of young men and women with advanced levels of training. Despite verifying conditions of valgus or varus knee, the studies presented different protocols and assessment methods. The implements comprised physioball, elastic resistance, and wedge. Electromyography and kinematics were used to assess muscle activity and movement patterns. These results reinforced the possibility of using implements to induce muscle and joint actions to reduce varus and valgus conditions. We suggest more studies to define the best strategies to reduce the excessive deviation of the patella in people who have valgus or varus knee

Estimation of specific VO2max for elderly in cycle ergometer

The aim of the present study was to develop and validate a specific estimation model of maximal oxygen consumption (VO2max) based on submaximal ventilatory indicators on a cycle ergometer test protocol in elderly men. We tested, using an incremental protocol, 181 healthy and non-athletes male volunteers, aged between 60 and 79 years old, randomly divided into two groups: group A, of estimation (n = 137), and group B, of validation (n = 44). The independent variables were: body mass in kg, second workload threshold (WT2) and heart rate at the second ventilatory threshold (VT2). The cross-validation method was used in group B, with group A serving as the basis for the model and the validation dataset. The results presented a multiple linear regression model for estimation of VO2max = 31.62 + 0.182 (WT2) – 0.302 (body mass) in mlO2/kg/min-1; adjusted R2 = 0.98 and SEE = 0.682 (mlO2/Kg/min-1). The construction of this specific model for healthy and non-athletes elderly men can demonstrate that it is possible to estimate VO2max with a minimum error (SEE < 1.00) from indicators of ventilatory thresholds obtained in an incremental submaximal test

Comparison of different flexibility training methods and specific warm-up on repetition maximum volume in lower limb exercises with female jazz dancers

Introduction: Some evidences show that stretching exercises prior to a strength training session can result in decrease of performance. Therefore, the aim of this study was to compare the acute effect of different stretching protocols in the lower limbs using the sum of repetition maximum (RM) performed before a strength training session. Material and methods: The sample consisted of ten female jazz dancers (age: 24.7 ± 7.84 years), with no experience in strength training. Six visits were conducted in which participants were subjected to 10-RM test, 10-RM retest and four different warm-up protocols: specific warm-up, static stretching, proprioceptive neuromuscular facilitation and ballistic stretching. Results: The results obtained in this study showed that in the squat exercise in the Smith machine, the ballistic stretching protocol had a significantly higher volume compared to all other protocols, while the PNF had a significantly higher volume in comparison with the specific warm-up protocol and static stretching protocol (p < 0.05). However, in the leg extension, there were no significant differences in the total volume of maximum repetitions between protocols. Conclusion: Ballistic stretching was the most effective protocol to increase the levels of muscle strength in female jazz dancers

Efeito agudo da técnica de autoliberação miofascial aplicada nos agonistas e antagonistas sobre o desempenho de repetições máximas, tempo sob tensão e percepção subjetiva de esforço na cadeira extensora

Objective: To investigate the effect of self-liberation myofascial technique applied in the agonist and antagonist muscles on the performance maximum repetitions, time under tension and perceived exertion in the extensor chair bodybuilders men at least six months. Methods: research was quantitative, randomized quasi-experimental, involving nine men with a mean age of 23.5 years (± 2,4). The experimental group was subjected to five sessions in which the first two were to measure the load 20 MRs, the third was the traditional and the last two were self-liberation agonist and antagonist. Was carried out initially using the Shapiro-Wilk test, homoscedasticity test (Bartlett criterion); A two-way ANOVA (3 x 4) for repeated measures followed by post hoc Bonferroni test. The Friedman test followed by Wilcoxon, with p ≤ 0.05. Results: The results of the study showed that the speed of execution between repetitions increased after the intervention. Conclusions: Myofascial self-liberation, when applied to the knee extensors, allowed a longer time under tension and may be a good strategy when the goal of the training is muscle power in the lower limbs, via increased execution speed.Objetivo: Verificar o efeito da técnica de auto liberação miofascial (ALMF) aplicada nos músculos agonistas e antagonistas sobre o desempenho repetições máximas, tempo sob tensão (TST), índice de fadiga (IF) e percepção subjetiva de esforço (PSE) em homens praticantes de musculação. Métodos: O presente estudo caracterizou-se como uma pesquisa quantitativa, quase-experimental, randomizada. Nove homens, experientes em treinamento de força, com idade média de 23,5 anos (± 2,4) foram submetidos a cinco sessões com um intervalo mínimo de 48h entre elas. Nas duas primeiras foram realizados o teste e reteste para 20 repetições máxima (RMs) no exercício de extensão de joelho realizado na cadeira extensora. Nas três visitas subsequentes foram realizadas de forma aleatória e randomizada os protocolos do mesmo exercício sem a ALMF, com a ALMF nos agonistas e com a ALMF nos antagonistas. Resultados: Os resultados demonstraram que nenhum dos protocolos com a ALMF representou influência no número de repetições realizadas (p ˃0,05). No entanto, a ALMF nos agonistas induziu um menor TST (20,4±2,1) comparado ao protocolo tradicional (21,0±42,1) para p˂ 0,05.  Conclusões: A ALMF, quando aplicada nos extensores do joelho pode ser uma estratégia interessante quando o objetivo do treinamento for otimizar o desempenho de potência muscular em membros inferiores de forma aguda.

Efeito da pré ativação dos antagonistas sobre a atividade eletromiográfica dos agonistas no exercício supino horizontal

ABSTRACT Effect of pre-activation of antagonists on agonists eletromyograph activy of the exercise supino horizontalObjective: To investigate the effect of pre-activation of antagonists on the electromyographic (EMG) activity of the agonists in the bench press exercise in multiple series. Methods: eight subjects physically active, 21.6 ± 1.18 years, were randomly assigned to two experimental protocols, with an interval of 30 minutes between them: a) bench press (BP); open rowing (OR) immediately followed the BP, so that the maximum rest between the exercises did not exceed 30 seconds. Three sets of eight repetitions maximum of BP and BP post OR with 3 minute break between sets. The EMG signals of the clavicular and sternocostal pectoral, clavicular deltoid and tríceps brachii long head. Results: We found a reduction in the first sets, for the pectoral clavicular muscle where no pre activation of the antagonist protocol. showed higher activity compared to the protocol activation of antagonists (p = 0.015). For the other muscles were no significant differences between sets in the protocols. Conclusion: The application of pre-activation of antagonists did not promote increased electrical activity of muscles of the study. Presenting the contrary, a reductions in the activation of the pectoral clavicular in the first set.Objetivo: Verificar o efeito da pré-ativação dos antagonistas sobre a atividade eletromiográfica (EMG) dos agonistas no exercício supino horizontal em séries múltiplas. Métodos: Oito homens, fisicamente ativos, com 21,6 ± 1,18 anos de idade foram randomizados para dois protocolos experimentais, com um intervalo de 30 minutos entre eles:  a) supino horizontal (SH); b) remada aberta (RA) seguida imediatamente do SH, de forma que o intervalo máximo entre os exercícios não ultrapassasse 30 segundos. Foram realizadas três séries de oito repetições máximas nos dois protocolos com 3 minutos de intervalo entre elas. O sinal eletromiográfico dos músculos peitoral maior partes clavicular e esternocostal, deltoide clavicular e tríceps braquial cabeça longa foram verificados na execução do supino horizontal. Resultados: Foi observado redução na primeira série para o músculo peitoral maior parte clavicular no protocolo com pré ativação dos antagonistas (p = 0,015). Para os demais músculos não foram encontradas diferenças significativas entre as séries, em ambos protocolos. Conclusão: A aplicação da pré-ativação dos antagonistas não promoveu aumento da atividade elétrica dos músculos investigados. Apresentada pelo contrário, uma redução na ativação do peitoral maior parte clavicular na primeira série.

Análise de conhecimentos e hábitos de hidratação de corredores de rua no município do Rio de Janeiro

The aim of this study was to analyze the knowledge and hydration habits of recreational road runners of 5 and 10 km in Rio de Janeiro city. This was a survey-type descriptive cross-sectional study. The sample consisted of 28 individuals, 18 men (age: 38.06 ± 13.39 years) and 10 women (age: 34.00 ± 6.55 years), road runners in Rio de Janeiro city, with minimum training frequency of three times a week. The data were collected through an adapted questionnaire, with questions about training characteristics, hydration habits and the importance of hydration. The questionnaire responses showed that 35.7% of the study participants have the habit of running for over two years, however, 53.6% of the participants did not seek guidance on the best way to hydrate. Most (61.5%) of those who received information about hydration resorted to a Physical Education teacher, although 64.3% of the sample run without the guidance of this professional and 10.7% are still unaware of some importance of hydration. Hydration of individuals occurs predominantly after the training (87%) and competitions (86.7%) with moderately cold liquids (57.1%), with isotonic (39.3%) and with water (100%). However, 39.3% of respondents are concerned about the hydration only in the summer. We conclude that runners surveyed hydrate with a certain frequency after the activities, but do not understand the importance of this action. Physical Education teacher is the most sought professional for information about hydrationO objetivo do estudo foi analisar conhecimentos e hábitos de hidratação de corredores de rua de 5 e 10 km no município do Rio de Janeiro. O trabalho caracteriza-se como um estudo descritivo, de corte transversal do tipo Survey. A amostra foi composta por 28 indivíduos, 18 homens (idade: 38,06 ± 13,39 anos) e 10 mulheres (idade: 34,00 ± 6,55 anos), corredores de rua da cidade do Rio de Janeiro, com frequência de treinamento mínima de três vezes por semana. Os dados foram coletados através de um questionário adaptado, composto de perguntas sobre características do treinamento, hábitos de hidratação e importância da hidratação. As respostas do questionário mostraram que 35,7% dos sujeitos do estudo têm o hábito de correr há mais de dois anos, porém 53,6% dos participantes não buscaram orientações quanto a melhor maneira de se hidratar. A maioria (61,5%) dos que buscaram informações sobre a hidratação recorreram a um profissional de Educação Física, apesar de 64,3% da amostra correr sem a orientação deste profissional e 10,7% ainda desconhecer alguma importância de se hidratar. A hidratação dos indivíduos se dá predominantemente após os treinos (87%) e competições (86,7%) com líquidos moderadamente gelados (57,1%) e isotônicos (39,3%) em conjunto com a água (100%). Todavia, 39,3% dos participantes se preocupam com a hidratação apenas no verão. Conclui-se que os corredores pesquisados se hidratam com certa frequência após as atividades, porém não entendem a importância dessa ação. O profissional de Educação Física é o profissional mais procurado para informar sobre a hidratação

Anthropometric and physical fitness parameters versus specific performance tests in Brazilian field hockey athletes: a pilot study

Study aim: To investigate the correlation between anthropometric parameters, Sargent jump test, core muscles endurance and agility performance versus specific tests with and without a ball in female Brazilian field hockey athletes

Determination and comparison of time under tension required to perform 8, 10 and 12-RM loads in the bench press exercise

Study aim: To determine and compare the time under tension (TUT) required to perform 8, 10 and 12 repetition maximum (RM) loads in the bench press exercise