Showing papers in "Revista Brasileira de Cineantropometria e Desempenho Humano in 2008"

Motor coordination: influence of age, sex, socio-economic status and levels of adiposity, in peruvian children

Abstract: The objective of this study was to describe motor coordination (CoM) levels, in addition to the infl uence of age, socioeconomic status (SES), sex and subcutaneous adiposity on the CoM of Peruvian children aged six to eleven years. The sample size was 4007 children (n=1889 females; n=2118 males) from several schools in the metropolitan area of Lima, Peru. CoM was assessed with the KTK (Kiphard and Schilling, 1974) test battery that includes 4 tests: balancing backward (BB), hopping on one leg (HO), jumping sideways (JS) and shifting platforms (SP). Subcutaneous adiposity included the sum of several skinfolds: triceps, subscapular and calf. Socioeconomic status (SES) was evaluated according to the physical location of each school (type of neighborhood). Exploratory, descriptive and inferential statistical analyses (ANOVA II as well as regression linear models) were performed using SPSS 15. Signifi cant increases in mean values of CoM were observed in both sexes and across age. Children with high adiposity exhibited lower performance in all tests. Boys outperformed girls. High SES has a greater infl uence only on HO, and a low SES proved relevant to BB performance. It can be concluded that CoM is highly specifi c to each gender. Body fat levels have a negative infl uence on each coordination test, as well as on overall coordination. SES does not seem to be a conclusive predictor of motor coordination in children.

Somatotipo como indicador de desempenho em atletas de futsal feminino

Abstract: The present study aimed to verify whether body somatotype was indicative of competitive success in female futsal (indoor soccer) players. One hundred and twelve players (22.1 ± 5.4 years; 58.4 ± 6.9 kg; 161.8 ± 6.2 cm), from ten teams and seven different states, had participated in a national competition. The anthropometric date was analyzed using one-way ANOVA for repeated measures. The somatotype dispersion distance was applied to compare somatotypes between the champion team (reference) and the other teams (from 2 nd to 10 th position). Anthropometric characteristics did not differ signifi cantly among teams. The results showed that the endomorphic component was predominant in relation to the mesomorphic and ectomorphic component, irrespective of a team’s ranking at the end of the competition. Therefore, the body somatotypes of female futsal teams cannot be considered as indicative of their competitive success.

Psychomotor reactions in fencing dependence of stimuli type

Abstract: O objetivo do presente estudo foi examinar o tempo de reacao (TR), tempo de movimento (TM) e sinal eletromiografico (EMG) durante os estimulos tatil, acustico e visual. Dois grupos de individuos participaram do estudo: um grupo composto por esgrimistas avancados (n= 12, idade media= 22,3), em media 8,3 anos de pratica; e o outro por esgrimistas novatos (n= 15, idade media= 14,8), em media 2,8 anos de pratica. A ferramenta de investigacao aplicada no estudo foi um inovador sistema de superficie eletromiografica, com equipamentos perifericos que permitiram acessar as reacoes aos estimulos tatil, acustico e visual dos participantes. O sistema tornou possivel gravar o TR e TM separadamente. Os individuos foram expostos a quarenta e cinco estimulos de modo randomizado, em cada tipo de estimulo. Os esgrimistas responderam mais rapidamente ao estimulo tatil e, em seguida, ao estimulo acustico, e de maneira mais lenta ao estimulo visual (p < 0,01). Os esgrimistas avancados exibiram valores significativamente mais baixos de TR, TM e sinal EMG, em comparacao aos esgrimistas novatos. Ambos os grupos exibiram um decrescimo no valor do sinal EMG durante as tentativas de estimulos tatil, acustico e visual, suportando a hipotese. Uma pequena coincidencia das curvas do sinal EMG tambem foi observada no teste de estimulo visual. Pode-se concluir que a percepcao visual reduz a tensao muscular nos esgrimistas novatos (p < 0,05).

Comparison of the health related physical fitness of adults of differents ages

Abstract: The objective of this study was to investigate possible differences in the levels of health related physical fitness of men and women of different ages. The sample comprised 326 people (132 men and 194 women) who did not perform regular physical exercise, and who were separated for analysis by sex and into three age groups: 20-29 years (G1), 30-39 years (G2) and 40-49 years (G3). All subjects underwent anthropometric measurements and motor performance testing (flexibility, muscle resistance/strength and cardiorespiratory fitness). Statistical analysis employed the Levene test to verify the homogeneity of variation, descriptive statistics, single factor ANOVA (age group) and the Bonferroni test. The significance level adopted was p<0.05. The best levels of physical fitness were observed among the youngest subjects (G1), irrespective of sex, while the worst fitness levels were detected in the oldest subjects (G3). The variation in body fat from G1 to G3 was more accentuated among the men (34%) than among the women (16%). With relation to motor performance, the greatest percentage differences between G1 and G3 were detected by either modified abdominal test (39%and 22%, for men and women respectively) and the arm flexion and extension test(31% and 24%, for men and women respectively. The results suggest that among individuals who do not regularly practice physical exercise there is a natural tendency for health related physical fitness to reduce as age increases.

Blood glucose responses of type-2 diabetics during and after exercise performed at intensities above and below anaerobic threshold

Abstract: With the objective of analyzing the blood glucose responses during and after exercise performed at 90 and 110% of anaerobic threshold (AT), 10 type-2 diabetes patients (56.9±11.2years; 80.3±14.4kg) performed an incremental test (IT) on a cycle ergometer. After an initial IT to identify AT, the volunteers participated in three experimental sessions on three different days: 20 minutes’ of cycling at either 90 or 110% of AT, and a control session (CON). Blood glucose was measured at rest, and at the 10th and 20th minutes of exercise or control condition, as well as every 15 minutes during a 2-hour postexercise recovery period (Rec). One-way ANOVA did not detect significant differences in blood glucose levels between the sessions at 90 and 110% of AT. Compared to CON, a signifi cant decrease was observed at the 20th minute of exercise, and at the 15th and 60th minutes of Rec from the 90% AT session. Significant reductions were also observed at the 10th and 20th minutes of exercise and at the 15th, 30th, 45th, 60th and 90th minutes of Rec from the session at 110% AT. Exercise performed at the higher intensity (110% AT) resulted in a tendency of a more pronounced and prolonged hypoglycemic effect during and after exercise, and may be an alternative intensity for glycemic control in type 2 diabetics who do not have cardiovascular complications or other contraindications to exercising at intensities above the AT.

Immediate effect of selective neuromuscular electrical stimulation on the electromyographic activity of the vastus medialis oblique muscle

Abstract: The Patellofemoral pain syndrome (PFPS) is described as an anterior or retropatellar knee pain in the absence of other associated diseases, and has often been associated with dysfunction of the vastus medialis oblique muscle (VMO). However, several studies have demonstrated the impossibility of selectively activating this muscle with exercises. The aim of the present study was to analyze the immediate effect of neuromuscular electrical stimulation of VMO muscle by means of monitoring the electromyographic activity of the vastus medialis oblique (VMO) and vastus lateralis (VL) muscles. Eighteen healthy women with a mean age of 23.2 years and mean BMI of 20 Kg/m2 were evaluated. The study protocol included electromyographic analysis of VMO and VL muscles, before and immediately after neuromuscular electrical stimulation of the VMO muscle. During the electromyographic analysis, the volunteers performed maximal voluntary isometric contraction in a 60° knee extension on an isokinetic dynamometer. “Russian current” apparatus was used for electrical stimulation. Results: The data analysis demonstrated a signifi cant increase in VMO activation intensity immediately after it had been electrically stimulated (p=0.0125), whereas VL activation intensity exhibited no signifi cant increase (p=0.924). Moreover, a significant increase in the VMO/VL ratio was also detected (p=0.048). In this study it was observed that electrical stimulation modifiedthe VMO/VL ratio, which suggests electrical stimulation has a benefi cial effect on VMO muscle strength.

Muscle activation during pedaling in different saddle position

Abstract: The purpose of this study was to analyze the effects on muscle activation pattern of different saddle positions during cycling Three elite cyclists followed a protocol that consisted of four different saddles positions, displaced forward, backward, upward and downward with relation to the reference position used in training and competition In all tests the saddle was displaced by 1cm The cyclists’ bicycles were mounted on a magnetic cycle simulator The load was normalized at the second ventilatory threshold Muscle activation of six lower limb muscles was registered: gluteus maximus, rectus femoris, biceps femoris, vastus lateralis, gastrocnemius medialis, and tibialis anterior The results demonstrated that relatively small saddle adjustments can affect the pattern of muscle activation and probably cycling technique

Efeitos da suplementação de creatina no exercício intermitente de alta intensidade: divergências e recomendações metodológicas

Abstract: Apos breve revisao da literatura existente acerca dos efeitos da suplementacao de creatina no rendimento em atividades intermitentes de alta intensidade, o objetivo principal dessa revisao foi discutir diferencas metodologicas dos estudos que possam explicar a divergencia encontrada na literatura. Os efeitos da suplementacao de creatina no exercicio intermitente de alta intensidade sao bastante investigados. Embora existam inumeros achados demonstrando a efi cacia desse suplemento nesse tipo de atividade, outras tantas evidencias nao suportam tal efeito ergogenico. A explicacao para essa divergencia parece ser multifatorial, porem sempre ligada as questoes metodologicas. O modelo do estudo (crossover ou grupos independentes paralelos), a variabilidade individual no conteudo muscular de creatina, o alto consumo de carnes, o tamanho da amostra, as caracteristicas do protocolo de exercicio (dependencia do peso corporal e tempo de intervalo entre as series), e diferencas de genero e idade entre estudos sao potenciais variaveis que explicam, em maior ou menor magnitude, a discrepância na literatura. Estudos envolvendo homens jovens, com modelo de grupos paralelos, poder estatistico satisfatorio, controle da incorporacao de creatina muscular, avaliacao do consumo alimentar e protocolos de exercicios intermitentes maximos, cujo rendimento nao depende do peso corporal, com intervalos de recuperacao entre 1 a 6 minutos, tendem a apresentar resultados positivos. Os diversos fatores metodologicos que podem contribuir para a divergencia acerca do tema devem ser considerados quando da realizacao de futuros estudos, bem como no momento da prescricao desse suplemento.