Tiritas nasales y entrenamiento de la fuerza resistencia en triatlón.

Resumen tomado de la publicación

O efeito do treinamento e destreinamento na força muscular de meninos pré-púberes

A treinabilidade de força em crianças tem sido bastante explorada, mas ainda existem alguns questionamentos: O quanto a força decresce quando a criança interrompe o treinamento? O objetivo deste estudo foi avaliar o comportamento da força muscular dinâmica isotônica (1-RM), pico de torque isocinético e pico de torque isométrico, na extensão de joelho (EJ) e na flexão de cotovelo (FC) de meninos durante 24 semanas, sendo 12 semanas de treinamento e 12 de destreinamento de força. Um grupo experimental (EX) de 7 meninos (9,4±1,6 anos) pré-púberes treinou de forma dinâmica, três vezes por semana, durante 12 semanas, com intensidade entre 60 e 85% do teste de 1-RM, obtendo um aumento de 78% e 67% na força de 1-RM da EJ e da FC respectivamente. No grupo controle (CO) participaram 7 meninos pré-púberes, pareados ao EX pela idade (9,7±1,7 anos). Eles não alteraram significativamente a força nas primeiras 12 semanas, mas, ao final das 24 semanas, aumentaram a força de 1-RM em 41% e 53% na EJ e FC, respectivamente. Após 12 semanas de destreinamento, a força absoluta de 1-RM da EJ e da FC do grupo EX apresentou uma queda estatisticamente não significativa de 33% e 21%, respectivamente. Quando corrigida pelo peso corporal e massa corporal magra (MCM), a força do grupo EX de 1-RM da EJ diminuiu 41% e 36% (p<0,05) respectivamente. Na FC, a força não apresentou redução significativa Os grupos EX e CO, não apresentaram alterações estatisticamente significativas (p>0,05) durantes as 24 semanas de estudo nos picos de torque isocinético e isométrico, os resultados foram os seguintes: no grupo EX a força isocinética de EJ em 60° e 90° foram 66,0±25,7 Nm para 79,8±26,1 Nm e 62,0±29,2 para 76,8±30,6 Nm respectivamente; e na FC em 60° e 90°, 16,0±8,9 para 13,3±8,2 Nm e 16,1±10,5 para 15,7±6,2 Nm respectivamente. Na força isométrica do grupo EX na EJ em 60° e 45° os resultados foram os seguintes: 96,9±35,6 para 108,3±61,9 Nm e 87,0±41,7 para 96,3±60,3 Nm respectivamente. Na FC em 60° e 90° de 20,3±7,1 para 22,5±8,2 Nm e de 21,7±6,7 para 21,5±9,1 Nm respectivamente. O grupo CO apresentou os seguintes resultados na força isocinética de EJ nos ângulos de 60° e 90°, de 55,1±14,4 para 76,6±15,4 Nm e 56,4±10,2 para 73,1±13,3 respectivamente. Na FC, de 13,1±3,9 para 13,9±3,6 Nm e 11,4±4,4 para 10,9±4,1 Nm em 60° e 90° respectivamente. Na força isométrica de EJ em 60° e 45° os resultados foram: 89,4±13,2 para 101,9±17,4 Nm e 73,7±10,5 para 84,1±10,8 respectivamente; e na FC em 60° e 90° foram de 16,1±4,8 para 17,7±4,7 e de 17,1±3,1 para 20,7±4,5 Nm respectivamente. Os resultados deste estudo mostram que, após 12 semanas de destreinamento, a queda de força de 1-RM, foi significativa quando expressada em valores corrigidos pelo peso corporal e MCM, apenas nos membrosinferiores. O processo de crescimento e maturação pode contribuir para tornar menos evidente a redução da força durante o destreinamento.

A influência da força e da flexibilidade no batimento de pernas e sua relação com a performance total de nadadores de 100 metros nado crawl

O objetivo do presente estudo foi verificar a influência da força e da flexibilidade no batimento de pernas e sua relação com a performance de nadadores de 100 metros nado crawl. Os 23 melhores nadadores, na prova de 100 metros nado crawl, do Campeonato Estadual Júnior e Sênior de Inverno, do Estado do Rio Grande do Sul, foram selecionados para este estudo. Os nadadores foram submetidos a: (1) avaliação da flexibilidade (flexão plantar), (2) avaliação da capacidade de produção de força (torque) isométrica e isocinética dos músculos extensores e flexores do joelho, (3) avaliação do batimento de pernas na distância de 100 metros e (4) avaliação da performance do nado crawl na distância de 100 metros. Inicialmente, a influência da força e da flexibilidade no batimento de pernas, foi analisada. Em seguida, a influência do batimento de pernas na performance total dos nadadores foi analisada. Após este procedimento, a amostra foi dividida em três grupos, conforme o tempo obtido no teste de batimento de pernas (grupo I: do 1º ao 8º tempo; grupo II: do 9º ao 16º tempo; e grupo III:do 17º ao 23º tempo), com o objetivo de verificar diferenças entre os grupos nas variáveis testadas Os valores obtidos (n=23) para correlação entre flexão plantar e batimento de pernas não foram significativos. Já nos subgrupos da amostra, somente o grupo I obteve correlação significativa (r=0,70 - p<0,05) entre flexão plantar e batimento de pernas. Os valores obtidos da força (torque) isométrica, resultante da flexão e extensão do joelho em um ângulo de 60º e os valores da força (torque) isocinética obtidos na velocidade de 370º/s não se correlacionaram com os resultados obtidos no teste de batimento de pernas, tanto na análise do grupo todo, quanto nos grupos estratificados. Os tempos de batimento de pernas (n=23) mostraram correlação significativa (r=0,70 – p<0,05) com a performance total. A análise nos subgrupos mostrou valores significativos somente para o grupo III (r=0,85 – p<0,05), mas não mostrou valores significativos para os grupos I e II. Os resultados sugerem que a força (torque) resultante da flexão e extensão do joelho em 60º (isométrico) e na velocidade de 370º/s (isocinético) não tem influência no batimento de pernas, enquanto a flexibilidade esta influenciando no batimento de pernas somente no grupo I. O batimento de pernas tem importância significativa para a performance total de nadadores de 100 metros nado crawl.

Correlação entre torque, equlíbrio e função do joelho após reconstrução do LCA

Background: Several studies emphasize the importance of assessing the knee function after anterior cruciate ligament (ACL) reconstruction. The influence of several variables on the function of these patients has been analyzed, but there is no consensus in the science literature. Purpose: To evaluate the correlation between the torque and balance on the knee function after ACL reconstruction. Methods: 23 males patients with ACL reconstruction were tested. The procedures of the study included analysis of concentric peak torque at 60o/s and 180o/s of quadriceps femoris and hamstring muscle with a isokinetic dynamometer. The balance in single-limb stance was measured with stabilometry. The functional performance were performed by two hop tests. To estimate the subjective function of the patients was applied Lysholm Knee Scoring Scale and a Global Rating scale. Results: The analysis of data showed a moderate positive correlation between knee extensor torque and functional performance tests (r= 0,48; p=0,02). A moderate negative correlation was found between the two variables of the stabilometry center of pressure and average speed of centre of pressure and the Global Rating scale (r = -0.4, p = 0,04 and r = -0,49, p = 0 ,02, respectively). No correlation was found between peak torque and balance in single-limb stance. Conclusion: The results of the present study suggest that knee extensor strength and postural balance have some influence on knee function in patients after ACL reconstruction

Desempenho muscular e equilíbriu postural em idosas frágeis residentes na comunidade

Human aging is physiological process causes alterations in several systems of the organism. In the musculoskeletal system, a main change is the decreased muscle strength, that in the lower extremity, compromises the ability to respond quickly with enough strength to prevent falls, causing alterations in postural balance. Currently, many researchers have study the human frailty, defined as a multifactorial syndrome, with excess of vulnerability to stressors, reducing ability in maintaining or regulating homeostasis. Its characteristics are directly related to physical function. Aim: To analyze muscle performance and postural balance in frail and pre-frail elderly women, and to compare them according with the frailty phenotypes criteria proposed by Fried 2001. Method: 39 frail elderly women living in the community, aged 65 years and older, were assessed muscle performance of lower extremity using isokinetic dynamometer and postural balance using Berg s balance scale and computerized baropodometry. Results: There was significant difference in plantar flexor, knee flexor and knee extensor strength, in anteroposterior (AP) oscillation with eyes open and on Berg s scores between groups. A weak correlation was observed between strength and balance. Conclusion: The results suggest that the frail elderly present worse muscle performance in lower extremity and worse postural balance compared to the pre-frail elderly. There were correlations between muscle performance and balance impairments in these elderly, but several variables are also involved in maintaining postural balance

Análise da função dos músculos do quadril em portadores de síndrome da dor patelofemural

The Patellofemoral pain syndrome is defined as a fore or retro patellar pain and it has multifactorial etiology, where the bad patellar alignment is the most acceptable hypothesis. However proximal factors to the knee, as the debility of the muscles of the hip, have been demonstrated as a contributing factor to the appearing of that syndrome. Purpose: To evaluate if exists a relation between the hip muscles performance and the development of the SDPF. Methods: Thirty women took part in this study. They were divided in two groups; a control group (fifteen asymptomatic subjects) and an experimental group (fifteen subjects with the diagnosis of SDPF). The muscle performance was evaluated in an isokinetic dynamometer, where it was verified the peak torque (PT), PT to body weight, PT time and the agonist/antagonist relation. It was also analyzed the electromyographic activity of the middle gluteus. The data was analyzed by the not paired t test at a significance level of 5%. Results:. Didn t have significant difference to the PT of the abductor muscles (p = 0,46) and lateral rotators of the hip (p = 0,17) between groups. Also didn t have significant difference to the PT values by the body weight, to these muscle groups either (p = 0,10 e p = 0,11, respectively). Didn t have significant difference between the amplitude of the signal (p = 0,05) and the onset of medium gluteus (p = 0,25) between the groups. Conclusion: In the experimental conditions realized, the study didn t demonstrate a relation between performance the hip muscles behavior and the development of the SDPF

Efeito imediato da estimulação elétrica neuromuscular seletiva do músculo VMO em pacientes com síndrome da dor femoropatelar

Patellofemoral pain syndrome (PFPS) is described as anterior or retropatellar pain knee in the absence of other pathologies and is frequently associated with dysfunction of the vastus medialis oblique (VMO). However, several studies have demonstrated the inability to selectively activate this muscle through exercise. To evaluate the effect of Neuromuscular Electrical Stimulation (NMES) selective VMO in women with syndrome. We evaluated thirty-eight women: twenty in the control group (24.15 ± 2.60 years) and eighteen diagnosed with PFPS (25.56 ± 3.55 years). Both groups were evaluated before and after a protocol of electro stimulation. To measure for comparing groups before and after treatment, we assessed the extensor torque concentric and eccentric knee through an isokinetic dynamometer, the intensity (Root Mean Square - RMS) and the onset of activation (onset) of VMO compared to the vastus lateralis (VL) in two types of exercise: open and closed kinetic chain. . Statistical analysis was performed using SPSS 15.0, with a significance level of 5%. Results: Our data showed an increase in the intensity of activation (RMS) of the VMO muscle after NMES in both study groups. During concentric contraction the RMS of the VMO before the NMES was 105.69 ± 32.26 μV and after a single intervention was 122.10 ± 39.62 μV (p = 0.048) for the control group. In the group with PPS, we found a similar behavior, with RMS of the VMO before NMES of 96.25 ± 18.83 μV and 139.80 ± 65.88 μV after the intervention (p = 0.0001). However, there was no evidence in the RMS value of VL muscle. The onset was calculated by subtracting the onset of VL by the onset of VMO. For the group with PFPS, the onset before the intervention was -0.007 ± 0.14 ms, indicating a delay of the VMO relative to VL, and after NMES was 0.074 ± 0.09 ms (p = 0.016), showing an activation previous VMO to VL. The same occurred for the control group. We also observed that NMES increased knee extensor power during the concentric contraction in both groups. Before the intervention the mean power was 28.97 ± 9.01 W for the PPS group and after NMES was 34.38 ± 7.61 W (p = 0.0001). Conclusion: We observed an increase in electromyographic activity of the VMO and also an anticipatory effect of this muscle

Influência da fadiga no comportamento neuromuscular do quadríceps femoral, após reconstrução do ligamento cruzado anterior

Muscle fatigue is a phenomenon that promotes physiological and biomechanical disorders and their changes in healthy subjects have been widely studied and have significant importance for care in preventing injuries, but we do not have many information about its effects in patients after ACL reconstruction. Thus, this study is to analyze the effects of fatigue on neuromuscular behavior of quadriceps after ACL reconstruction. To reach this objective, participants were forty men, twenty healthy (26,90 ± 6,29 years) and twenty after ACL reconstruction (29,75 ± 7,01 years) with a graft of semitendinosus and gracilis tendons, between four to six months after surgery. At first, there was an assessment of joint position sense (JPS) at the isokinetic dynamometer at a speed of 5°/s and target angle of 45° to analyze the absolute error of JPS. Next, we applied the a muscle fatigue protocol, running 100 repetitions of isokinetic knee flexion-extension at 90°/s. Concurrently with this protocol, there was the assessment of muscle performance, as the peak torque (PT) and fatigue index, and electromyographic activity (RMS and median frequency). Finally, we repeated the assessment of JPS. The statistical analysis showed that patients after ACL reconstruction have, even under normal conditions, the amended JPS compared with healthy subjects and that after fatigue, both have disturbances in the JPS, but this alteration is significantly exacerbated in patients after ACL reconstruction. About muscle performance, we could notice that these patients have a lower PT, although there are no differences between the dynamometric and EMG fatigue index. These findings show the necessity about the cares of pacients with ACL reconstruction in respect of the risks of articulate instability and overload in ligamentar graft

Efeitos da eletroestimulação sobre os parâmetros eletromiográficos e dinamométricos do músculo quadríceps femoral

To analyze the effects of electrical stimulation at two frequencies on the EMG parameters (EMG) and dynamometer, in muscles with different typing. MATERIALS AND METHODS: This is a controlled clinical trial, randomized and double blind. Sixty healthy volunteers (23.6 ± 4.2anos; 54.2 ± 7.7kg, 1.62 ± 0.009 cm) of both sexes were divided randomly into three groups: control group (CG), experimental group 1 (SG1) with application of the current Russian 30 HZ and experimental group 2 (EG2) at 70 Hz The volunteers performed an initial assessment (AV1) on the isokinetic dynamometer with three repetitions maximum voluntary isometric (MVC) for knee extension concomitant uptake of EMG for the VM muscle, VL and RF. Later, after application of NMES, they underwent an experimental protocol of isometric fatigue using 70% of MVIC, ending with the completion of a final assessment (AV2) in the same manner as the AV1. RESULTS: By analyzing the profile of the 60 subjects in three broad, VM showed a higher value of RMS behavior when the VL and RF (p = 0.03 and p = 0.02). With respect to Fmed the RF muscle (p = 0.001) showed a higher value for the VM. The VM muscle showed significant increases of Fmed (p = 0.05) after electrical stimulation at 70 Hz when compared the AV1 AV2 and RF showed significant decreases (p = 0.009) after stimulation at 30 Hz during the fatigue showed an increase RMS in the VM and VL, with a reduction in RF. For the variable Fmed was observed in three broad decline during fatigue. CONCLUSION: Our findings provide evidence that the muscles VM, VL and RF fiber typing are different besides indicating that the frequency of NMES tend to relate to the muscle stimulated. Finally suggests the surface EMG as a noninvasive method for characterizing muscle

Efeito do tempo de repouso após fadiga induzida no desempenho neuromuscular do quadríceps femoral: ensaio clínico, controlado, randomizado, cego

Objective: To evaluate the effect of different resting periods, after induced muscle fatigue, in the quadriceps femoris neuromuscular performance, in healthy subjects. Methods: Sixty-four volunteers, of both genders, with an average of 21,8 ± 1,7 years and mean body mass index of 24,2 ± 3,7 Kg/m2 were randomly assigned into 4 groups: control group (was not induced fatigue); Experimental Group 1 (Exp. 1 1 minute of rest after fatigue); Experimental Group 3 (Exp. 3 3 minutes of rest after fatigue) and Experimental Group 5 (Exp. 5 5 minutes of rest after fatigue). The subjects were evaluated to the knee´s joint position sense (JPS), followed by 5 flexion-extension knee concentric isokinetic contractions at 60°/s, with concomitant recording of median frequency (Fmed) of rectus femoris (RF), vastus lateralis (VL) and vastus medialis (VM). Then they underwent a muscle fatigue protocol (30 flexion-extension knee concentric contractions at 60°/s) and were reevaluated on the isokinetic performance, Fmed and JPS. Blood lactate levels were measured before initial assessment, immediately after the fatigue protocol and 5 minutes after the end of the rest period. Results: The adoption of 3 minutes of rest was sufficient to restore the initial conditions for the peak torque normalized by body weight and the VL and VM Fmed. The joint position sense returned to its initial values with 1 minute rest. The lactate concentration remained high regardless of the adopted rest period. Conclusion: The use of 3-minute rest period is sufficient for the reestablishment of the neuromuscular parameters to the pre fatigue values.

Efeito do método pilates no desempenho muscular e no equilíbrio corporal de mulheres idosas: ensaio clínico controlado randomizado

Background: The Pilates Method is a modality of exercise that has been growing in recent decades, but few researches has been conducted with elderly and little is known about its benefits in this population. Objective: To evaluate the effect of a program of Mat Pilates exercises in muscle performance and postural balance in elderly women. Materials and Method: This is a randomized controlled trial that evaluated the muscle performance (isokinetic dynamometer Biodex System 3 Pro®) and postural balance (Balance Master System®) of 33 women aged 65-80 years. The experimental group (EG) participated of a 12-week program of Mat Pilates exercises with two weekly sessions. Data normality was verified by the Shapiro - Wilk test and were adopted p value < 0.05 as significance level. Results: There were no differences between groups after training. However, the EG showed an increase in the values of extension and flexion average power to 60 ° / s after training (32.19 W to 37.04 W and 14.48 W to 17.56 W, respectively). Conclusion: The proposed exercise program was not effective in the total work and average power of flexor and extensor of the knee, as well as static and dynamic balance of participants

Efeitos agudos do alongamento estático antes e após exercício e as características neuromusculares do membro inferior: estudo controlado, randomizado e cego

Objective: To evaluate the acute effects of static stretching before and after isokinetic exercise, neuromuscular and biomechanical properties of muscles Biceps Femoris (BF) and semitendinosus (ST). Methods: Eighty-nine volunteers of both genders, healthy and physically active, with a mean age of 22.52 ± 2.6 years and mean BMI 23.86 ± 3.2 kg/m² were randomized into 4 groups: Control Group (CG) made only one Protocol Exercise (PE) without performing the stretching, the Experimental Group 1 (EG1) did stretching before PE; EG2 did the stretching after PE and EG3 did stretching before and after PE. The volunteers were evaluated on the following variables: Range of motion (ROM), soreness, dynamometric variables concentric and eccentric, Neuromuscular Latency Time (NLT) and electromyographic. In the data analysis was assigned a significance level of 5%. Results: ADM and TLNM reported significant reduction in CG, but remained unchanged in GE with p<0,05 and p<0,01, respectively. As for the soreness, no differences between the groups. The electromyographic activity of the BF and ST, in the concentric phase, showed a significant decrease in all groups (p<0,01). However, in the eccentric phase, ST revealed reduction in all groups (p <0.01), except for the CG, while the BF remained unchanged in all groups. The PT showed significant reduction in both conditions (concentric and eccentric) for all groups, with no difference between them (p<0,01). Conclusion: The results of this study do not favor the use of static stretching, even of short duration, before physical activity. However, after exercise or at times unrelated to the sport, he should be given with the aim of avoiding muscle shortening

Efeito da crioterapia e da laserterapia na resposta ao dano muscular induzido pelo exercício excêntrico: ensaio clínico e randomizado

Exercise-induced muscle damage mainly affects individuals who returned to physical activity after a time without practicing it or had some kind of exhaustive exercise, particularly eccentric exercise. To evaluate the effect of cryotherapy and laser therapy in response to muscle damage induced by eccentric exercise on the biceps muscle. This was a randomized clinical trial consisting of 60 female subjects. All subjects initially underwent an evaluation consisting of perimetry, measurement of pain sensation (via algometry and visual analogue scale), electromyography and dynamometry. Then the subjects performed an exercise protocol on the isokinetic dynamometer consisting of 2 sets of 10 eccentric elbow flexors contraction at 60 °/s. Completed this protocol, an intervention was held according to a previously random group distribution: control group (no intervention), cryotherapy group and laser therapy group. Finally, subjects were re-evaluated immediately and 48 hours after the intervention protocol, except for Visual Analogue Scale (VAS), which was also evaluated 24 hours after exercise. The circumference of the limb, the pain sensation (VAS and algometry), the muscle activation amplitude (via Root Mean Square - RMS), median frequency, peak torque normalized per body weight, average peak torque, power and work were analyzed. The median frequency immediately after the intervention protocol on the cryotherapy group was the only variable that showed inter and intra-group differences; the remaining variables showed only intragroup differences. The perimetry values did not change immediately after the protocol on the groups which underwent cryotherapy and laser therapy, however, there was an increase after 48 hours; algometry values decreased in all groups for 48 hours and the VAS values increased 24 and 48 hours also for all groups. Regarding RMS no significant change was observed. For dynamometry, peak torque normalized per body weight and average peak torque had a similar behavior, with a reduction in the post protocol that has remained after 48 hours. For the power and work, a decrease was observed immediately after the protocol with a further reduction after 48 hours. Cryotherapy and laser therapy does not alter the muscle damage response, except for the perimetry values immediately after exercise.

Taxa de desenvolvimento de força em diferentes velocidades de contrações musculares

O objetivo deste estudo foi comparar a taxa de desenvolvimento de força (TDF) nas contrações isométrica e isocinética concêntrica a 60°.s-1 e 180°.s-1. Quatorze indivíduos do gênero masculino (idade = 23,1 ± 2,8 anos; estatura = 174 ± 31,3cm; massa corporal = 81 ± 12kg) realizaram inicialmente uma familiarização ao equipamento isocinético. Posteriormente, os indivíduos realizaram em ordem randômica cinco contrações isocinéticas máximas para os extensores do joelho a 60°.s-1 e 180°.s-1 para determinar o torque máximo concêntrico (TMC) e duas contrações isométricas máximas de 3s para determinar o torque máximo isométrico (TMI). O TMI (301,4 ± 56,0N.m) foi maior do que o TMC a 60°.s-1 (239,8 ± 42,2N.m) e 180°.s-1 (175,0 ± 32,5 N.m). O TMC a 60°.s-1 foi maior do que o TMC a 180°.s-1. Para os intervalos de 0-30ms e 0-50ms, a TDF na condição isométrica (1.196,6 ± 464,6 e 1.326,5 ± 514,2N.m.s-1, respectivamente) foi similar à TDF a 60°.s-1 (1.035,4 ± 446,2 e 1.134,3 ± 448,4N.m.s-1) e maior do que a 180°.s-1 (656,7 ± 246,6 e 475,2 ± 197,9N.m.s-1), sendo ainda que a TDF na contração concêntrica a 180°.s-1 foi menor do que a 60°.s-1. No intervalo de 0-100ms, a TDF da contração isométrica (1.248,8 ± 417,4N.m.s-1) foi maior que a obtida na contração isocinética rápida (909,2 ± 283,4N.m.s-1). A TDF obtida na contração isocinética lenta (1.005,4 ± 247,7N.m.s-1) foi similar à obtida na contração isométrica e na concêntrica isocinética rápida. No intervalo 0-150ms, a TDF isométrica (1.084,2 ± 332,1N.m.s-1) foi maior do que as concêntricas (60°.s-1 e 180°.s-1) (834,8 ± 184,2 e 767,6 ± 201,8N.m.s-1, respectivamente), não existindo diferenças entre estas duas últimas. Conclui-se que a TDF é dependente do tipo e da velocidade de contração, suportando a hipótese de que maiores velocidades de contração acarretam maior inibição do drive neural no início do movimento.

Comparação entre a utilização de saliva e sangue para determinação do lactato mínimo em cicloergômetro e ergômetro de braço em mesa-tenistas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)