Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
1.
Appl Physiol Nutr Metab ; 48(6): 469-478, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-36857740

RESUMO

There is a popular belief that meat consumption is necessary to optimize adaptations to strength training (ST), but evidence to support this hypothesis is scarce. Therefore, this study aimed to compare ST adaptations in lacto-ovo-vegetarians (LOV) and non-vegetarians (NV) with adjusted protein intake per meal. Sixty-four LOV and NV performed 12 weeks of ST and were instructed to ingest at least 20 g of protein in each main meal during the experimental period. Quadriceps femoris muscle thickness (QFMT), knee extension one-repetition maximum (1RM), and isometric peak torque (PT), as well as participants' body composition were assessed before and after the intervention. Dietary intake was assessed throughout the study. After 12 weeks, similar increases in QFMT (LOV: 9.2 ± 5.4; NV: 5.5 ± 8.1 mm), knee extension 1RM (LOV: 24.7 ± 11.1; NV: 21.6 ± 9.8 kg), and PT (LOV: 29.8 ± 33.4; NV: 17.5 ± 19.4 N m) and lean body mass (LOV: 1.3 ± 0.9; NV: 1.4 ± 1.4 kg), alongside a decrease in body fat mass (LOV: -0.5 ± 1.6; NV -0.8 ± 1.6 kg) were observed in both groups at the end of the training period (p < 0.05). LOV had lower protein consumption than NV throughout the study (p < 0.05), but participants reached intake of at least 1.2 g of protein/kg/day during the experimental period. In conclusion, LOV and NV displayed similar improvements in muscle mass, strength, and in body composition after 12 weeks of ST, suggesting that meat consumption and higher protein intake in NV did not bring about further benefits to early adaptations to ST. This study was registered in Clinical Trials (NCT03785002) on 24 December 2018.


Assuntos
Treinamento Resistido , Humanos , Composição Corporal , Adaptação Fisiológica , Músculo Quadríceps , Aclimatação , Força Muscular/fisiologia , Músculo Esquelético/fisiologia
2.
Exp Gerontol ; 134: 110914, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-32145293

RESUMO

The purpose of this study was to investigate the effects of two water-based aerobic programs on cardiorespiratory and neuromuscular outcomes in older women. Forty-one women (60 to 75 years old) volunteered to participate in the study. Participants were randomized into a water-based continuous (CTG; n = 21; 63.9 ± 2.5 years) or an interval (ITG; n = 20; 64.8 ± 3.6 years) aerobic training group. Both training programs were performed for 12 weeks (45-min sessions twice a week), with exercise intensity based on rating of perceived exertion (Borg's RPE 6-20 Scale). Pre and post training assessments of cardiorespiratory and neuromuscular outcomes were performed. Data analyses were conducted using Generalized Estimating Equations and Bonferroni post-hoc test (α = 0.05). After the intervention, the CTG and the ITG displayed similar improvements in time to exhaustion (8% vs. 11%), peak oxygen uptake (9% vs. 7%), maximal dynamic knee extension strength (5% vs. 6%), dynamic muscular endurance of knee extensors (10% vs. 11%), maximal vastus lateralis electromyographic signal amplitude (13% vs. 35%), as well as an increase in muscle thickness (5% vs. 6%) and decrease in muscle echo intensity (-2% vs. -3%) of the quadriceps femoris. In conclusion, older women benefited from water-based exercise training prescribed based on participants' RPE, with both the interval and the continuous training programs resulting in similar increases in the cardiorespiratory and neuromuscular parameters.

3.
Clin Exp Hypertens ; 42(5): 401-408, 2020 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31594394

RESUMO

The present crossover design study investigated acute hemodynamic responses to two sets of leg press (LP) and bench press (BeP) at 10 and 20 repetition maximum (RM) in ten normotensive young men. At the end of each set, an increase in systolic blood pressure (SBP), heart rate (HR), and rate pressure product (RPP) was observed (p < .01), with no differences between intensities, but SBP was greater during the LP exercise (p < .01). Lower resting values of diastolic blood pressure (DBP) were observed in the post-BeP exercise period (p < .05), suggesting that DBP post-exercise hypotension may be more evident after upper-limb exercise.


Assuntos
Pressão Sanguínea/fisiologia , Exercício Físico/fisiologia , Extremidades , Hipotensão Pós-Exercício , Treinamento Resistido , Adulto , Estudos Cross-Over , Extremidades/irrigação sanguínea , Extremidades/fisiopatologia , Voluntários Saudáveis , Frequência Cardíaca/fisiologia , Hemodinâmica/fisiologia , Humanos , Masculino , Hipotensão Pós-Exercício/diagnóstico , Hipotensão Pós-Exercício/etiologia , Hipotensão Pós-Exercício/fisiopatologia , Treinamento Resistido/efeitos adversos , Treinamento Resistido/métodos , Descanso/fisiologia
4.
BMC Public Health ; 19(1): 657, 2019 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-31142294

RESUMO

BACKGROUND: Hypertension is a clinical condition highly prevalent in the elderly, imposing great risks to cardiovascular diseases and loss of quality of life. Current guidelines emphasize the importance of nonpharmacological strategies as a first-line approach to lower blood pressure. Exercise is an efficient lifestyle tool that can benefit a myriad of health-related outcomes, including blood pressure control, in older adults. We herein report the protocol of the HAEL Study, which aims to evaluate the efficacy of a pragmatic combined exercise training compared with a health education program on ambulatory blood pressure and other health-related outcomes in older individuals. METHODS: Randomized, single-blinded, multicenter, two-arm, parallel, superiority trial. A total of 184 subjects (92/center), ≥60 years of age, with no recent history of cardiovascular events, will be randomized on a 1:1 ratio to 12-week interventions consisting either of a combined exercise (aerobic and strength) training, three times per week, or an active-control group receiving health education intervention, once a week. Ambulatory (primary outcome) and office blood pressures, cardiorespiratory fitness and endothelial function, together with quality of life, functional fitness and autonomic control will be measured in before and after intervention. DISCUSSION: Our conceptual hypothesis is that combined training intervention will reduce ambulatory blood pressure in comparison with health education group. Using a superiority framework, analysis plan prespecifies an intention-to-treat approach, per protocol criteria, subgroups analysis, and handling of missing data. The trial is recruiting since September 2017. Finally, this study was designed to adhere to data sharing practices. TRIAL REGISTRATION: NCT03264443 . Registered on 29 August, 2017.


Assuntos
Promoção da Saúde/métodos , Hipertensão/prevenção & controle , Estilo de Vida , Idoso , Protocolos Clínicos , Humanos , Pessoa de Meia-Idade
5.
Eur J Sport Sci ; 18(10): 1398-1404, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30009683

RESUMO

Isokinetic hamstring-to-quadriceps (H:Q) ratios are frequently used to assess knee muscle strength imbalances and risk of injuries/re-injuries. The use of peak torque (PT) or total work (TW) to estimate joint stability may lead to different results because of the differences between these two neuromuscular variables. Thus, the current study aimed to compare the conventional and functional H:Q ratios calculated by PT and TW. Ninety-three male professional soccer players from Brazilian first division teams performed isokinetic concentric and eccentric contractions of the quadriceps and the hamstrings at 60°/s. Muscle strength balance was calculated using the conventional torque ratio (CTR) and conventional work ratio (CWR), functional torque ratio (FTR) and functional work ratio (FWR) were highly and moderately correlated between them (r = 0.83 and r = 0.73, respectively). The Wilcoxon statistical test revealed significant differences between CTR and CWR, as well as FTR and FWR (p < 0.05). T-test demonstrated significant differences in mean CTR-CWR and FTR-FWR, whereas Bland-Altman plots showed non-consistent bias. In addition, the chi-square test demonstrated significant differences between players below the conventional reference values and functional reference values (p < 0.001). In conclusion, TW ratios seem to provide distinct and additional information regarding the H:Q strength balance in professional soccer players. Moreover, taking into account that TW captures torque information throughout the entire range of motion, it is possible that TW ratios represent a more comprehensive assessment of muscle strength imbalance.


Assuntos
Músculos Isquiossurais/fisiologia , Articulação do Joelho/fisiologia , Força Muscular , Músculo Quadríceps/fisiologia , Futebol/fisiologia , Adulto , Atletas , Humanos , Masculino , Amplitude de Movimento Articular , Torque , Adulto Jovem
6.
J Appl Physiol (1985) ; 122(4): 1031-1039, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-28153942

RESUMO

Endothelial function and microvesicle concentration changes after acute bouts of continuous eccentric exercise have not been assessed previously nor compared with concentric exercise at similar aerobic power outputs. This method of training may be useful among some clinical populations, but acute responses are not well described. As such, 12 healthy males completed 2 experimental sessions of either 45 min of eccentric or concentric cycling at a matched aerobic power output below the ventilatory threshold. Brachial artery vascular function was assessed throughout 5 min of forearm ischemia and 3 min thereafter, before and at 5 and 40 min of recovery following each exercise session [flow-mediated dilation (FMD)]. Venous blood samples were acquired before each vascular function assessment. FMD significantly decreased after eccentric cycling by 40 min of recovery (P < 0.05), but was unaltered after concentric exercise. No differences in peak hyperemic blood flow velocity occurred neither between modalities nor at any time point (P > 0.05). Platelet-derived microvesicles increased by ~20% after both exercise modalities (P < 0.05) while endothelial-derived microvesicles were unchanged (P > 0.05). Moderate relationships with cardiac output, a surrogate for shear stress, and norepinephrine were apparent (P < 0.05), but there were no relationships with inflammatory or acute phase proteins. In summary, eccentric endurance exercise induced macrovascular endothelial dysfunction; however, endothelial activation determined by endothelial microvesicles did not occur suggesting that this modality may induce oxidative stress but no significant endothelial damage. In addition, the increase in platelet microvesicle concentrations may induce beneficial microvascular adaptations as suggested by previous research.NEW & NOTEWORTHY Continuous eccentric cycling exercise induces substantial skeletal muscle, tendon, and bone strain providing a potentially beneficial stimulus among clinical populations. This modality also induces temporary endothelial dysfunction but no apparent damage or activation of the endothelium indicated by microvesicle production, whereas proangiogenic platelet microvesicles are released similarly following both concentric and eccentric cycling and may relate to the shear stress and catecholamine response to exercise.


Assuntos
Ciclismo/fisiologia , Plaquetas/fisiologia , Micropartículas Derivadas de Células/fisiologia , Endotélio Vascular/fisiologia , Exercício Físico/fisiologia , Adulto , Velocidade do Fluxo Sanguíneo/fisiologia , Humanos , Masculino , Vasodilatação/fisiologia , Adulto Jovem
7.
Ultrasound Med Biol ; 43(5): 943-957, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28237637

RESUMO

The aim of this study was to assess the reproducibility of non-invasive, ultrasound-derived wave intensity (WI) in humans at the common carotid artery. Common carotid artery diameter and blood velocity of 12 healthy young participants were recorded at rest and during mild cycling, to assess peak diameter, change in diameter, peak velocity, change in velocity, time derivatives, non-invasive wave speed and WI. Diameter, velocity and WI parameters were fairly reproducible. Diameter variables exhibited higher reproducibility than corresponding velocity variables (intra-class correlation coefficient [ICC] = 0.79 vs. 0.73) and lower dispersion (coefficient of variation [CV] = 5% vs. 9%). Wave speed had fair reproducibility (ICC = 0.6, CV = 16%). WI energy variables exhibited higher reproducibility than corresponding peaks (ICC = 0.78 vs. 0.74) and lower dispersion (CV = 16% vs. 18%). The majority of variables had higher ICCs and lower CVs during exercise. We conclude that non-invasive WI analysis is reliable both at rest and during exercise.


Assuntos
Artéria Carótida Primitiva/anatomia & histologia , Artéria Carótida Primitiva/fisiologia , Exercício Físico/fisiologia , Ultrassonografia/métodos , Adulto , Velocidade do Fluxo Sanguíneo/fisiologia , Artéria Carótida Primitiva/diagnóstico por imagem , Feminino , Humanos , Masculino , Valores de Referência , Reprodutibilidade dos Testes , Descanso
8.
Muscle Nerve ; 55(1): 9-15, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27145419

RESUMO

INTRODUCTION: The aim of this study was to examine the associations between quadriceps muscle functionality features in nonactive older men to determine predictors of functional performance. METHODS: Quadriceps functional parameters, including quadriceps echo intensity (QEI), rate of torque development (RTD), and the 30 s sit-to-stand test (30SS), were assessed in 50 healthy sedentary older men (66 ± 5.4 years). RTD/QEI ratios were also calculated to identify the best predictor of functional performance. RESULTS: 30SS performance was associated with RTD, muscle thickness, RTD-50/QEI, RTD-100/QEI, RTD-50/QEI/WBM, and RTD-100/QEI/WBM. A multiple stepwise linear regression demonstrated that QEI was the best single predictor of functional performance, explaining ∼30% of the 30SS variance. CONCLUSIONS: These results indicate that QEI was the strongest contributor to functionality of nonactive older men, suggesting that QEI may be an alternative tool for screening of muscle impairment that leads to decreased functional performance in this population. Muscle Nerve 55: 9-15, 2017.


Assuntos
Envelhecimento , Contração Isométrica/fisiologia , Força Muscular/fisiologia , Músculo Quadríceps/fisiologia , Idoso , Análise de Variância , Tolerância ao Exercício/fisiologia , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Postura , Comportamento Sedentário , Torque
9.
Rev. bras. cineantropom. desempenho hum ; 17(3): 347-356, May.-June 2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-766350

RESUMO

Abstract The aim of this study was to compare the muscle thickness (MT), muscle quality (MQ), and functionality of two different age groups of active elderly women. Twenty seven older women (between 60 and 80 years old), physically active was dividing in two age groups: old 60-66 years (Old) and old 73-80 years (Older) volunteered for the present study. Knee extension isometric peak torque (PT) was obtained during a muscle isometric voluntary contraction (MIVC), and the value was normalized by MT. The Quadriceps Echo Intensity (QEI) was defined as the mean Echo Intensity (EI) value founded in all quadriceps muscle portions in ultrasound imaging. Was found MIVC increased (p=0.024) in the O1 (120.26±24.77 N/m) group when compared with the O2 (99.25±20.95 N/m) group, but when the MIVC was normalized the difference did not exist between groups (p≥0.05). The QEI was found increased in the Older group (97.10±17.35 a.u.) when compared with the Old group (80.18±14.95 a.u.) (p<0.05). Contrary to that, the QMT did not differ significantly between the groups (p≥0.05). The Old group presented a significant higher number of repetitions in the 30SS (14.13±2.29 repetitions) when compared to Older group (11.25±1.95 repetitions) (p<0.05). We observed that even without significantly greater muscle size, the Old group presented the results of 30SS significantly greater when compared with the older group. Besides that, the QEI was found increased in the older group and suggests that EI may be the best predictor of functional capacity than muscle quantity in active older woman.


Resumo Comparar a espessura muscular (EM), qualidade muscular (QM), e a funcionalidade entre dois grupos de mulheres idosas. Vinte e sete mulheres idosas (entre 60 e 80 anos) fisicamente ativas foram divididas em dois grupos: Grupo Old (n=15, 60-66 anos) e grupo Older (n=12, 73-80 anos). O pico de torque (PT) isométrico dos extensores de joelho foi obtido por contração isométrica voluntária máxima (CIVM), e seu valor foi normalizado pela EM. A espessura muscular do quadríceps femoral (EMQ) foi definida como o somatório da espessura muscular de todas as porções do quadríceps, e a qualidade muscular foi estimada pela média da Eco Intensidade do quadríceps femoral (EIQ). O grupo Old apresentou maiores valores absolutos de PT (120,3±24,8 N.m) comparado ao grupo Older (99,2±20,9 N.m) (p<0,05), entretanto os valores relativizados por espessura muscular não apresentaram diferenças entre grupos (p≥0,05). A EIQ foi maior no grupo Old (97,1±17,3 u.a.) quando comparado ao grupo Older (80,2±14,9 u.a.) (p<0,05). Não houve diferença significante na EMQ entre os grupos (p≥0,05). O grupo Old realizou um número maior de repetições no teste 30-sit-to-stand (30SS) (14,1±2,3 repetições) comparado ao grupo Older (11,2±1,9 repetições) (p<0,05). O grupo Old realizou um maior número de repetições no teste 30SS quando comparado ao grupo Older, embora ambos os grupos tenham apresentado valores semelhantes de EMQ. A EIQ foi maior no grupo Older, o que sugere que a eco intensidade parece ser uma variável melhor preditora da capacidade funcional do que a massa muscular em mulheres idosas ativa.

10.
Exp Gerontol ; 60: 207-14, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25449853

RESUMO

Concurrent training is an effective method for increasing skeletal muscle performance in aging individuals, but controversy exists as to whether chronic neuromuscular and functional adaptations are affected by the intra-session exercise sequence. Therefore the aim of this study was to evaluate the effect of concurrent endurance and power-like strength training exercise sequence on muscular and functional adaptations of older participants. Thirty-six healthy older men not engaged in systematic exercise training programs for at least 6 months were divided into a control group (CON; 65.8±5.3 years), or in the training groups: endurance-strength (ES; 63.2±3.3 years), or strength-endurance (SE; 67.1±6.1 years). Training groups underwent 12 weeks of concurrent endurance and power-like strength training, starting every exercise session with either endurance (in ES) or strength (in SE) exercises. Measurements included knee extension one repetition maximum (1RM), knee extension power, 30 second sit-to-stand test (30SS), maximum vastus lateralis surface electromyographic activity, and rectus femoris echo intensity (RFEI). Significant increases in maximal strength (ES +18±11.3%; SE +14.2±6.0%; p≤0.05), peak power (ES +22.2±19.4%; SE +26.3±31.3%; p≤0.05), and 30SS performance (ES +15.2±7.2%; SE +13.2±11.8%; p≤0.05) were observed only in the training groups, with no differences between ES and SE. Maximum muscular activity was greater after 12weeks at training groups (p≤0.05), and reductions in RFEI were found only in ES and SE (p≤0.05). These results demonstrate that concurrent strength and endurance training performed twice a week effectively increases muscular performance and functional capacity in older men, independent of the intra-session exercise sequence. Additionally, the RFEI decreases indicate an additional adaptation to concurrent training.


Assuntos
Adaptação Fisiológica , Resistência Física/fisiologia , Treinamento Resistido , Idoso , Exercícios em Circuitos , Eletromiografia , Exercício Físico/fisiologia , Teste de Esforço , Humanos , Masculino , Pessoa de Meia-Idade , Contração Muscular/fisiologia , Força Muscular/fisiologia , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/fisiologia , Consumo de Oxigênio/fisiologia , Ultrassonografia
11.
Age (Dordr) ; 36(3): 9625, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24515898

RESUMO

Increased proportion of non-contractile elements can be observed during aging by enhanced skeletal muscle echo intensity (EI). Studies have demonstrated that an increase in rectus femoris EI may affect physical performance. However, it is still unknown whether the whole quadriceps femoris EI (QEI) influences strength, power, and functional capacity of an older population. Therefore, the aim of the present study was to determine the correlation between QEI, the four individual quadriceps portions EI, and muscular performance of older men. Fifty sedentary healthy men (66.1 ± 4.5 years, 1.75 ± 0.06 m, 80.2 ± 11.0 kg) volunteered for the present study. The QEI and EI of the four quadriceps portions were calculated by ultrasound imaging. Knee extension one repetition maximum (1RM), isometric peak torque (PT), and rate of torque development (RTD) were obtained as measures of muscular strength. Muscular power was determined by knee extension with 60 % of 1RM and countermovement jump (CMJ). The 30-s sit-to-stand test was evaluated as a functional capacity parameter. QEI and all individual EI were correlated to functional capacity and power during CMJ (p ≤ 0.05), but rectus femoris EI was not related to knee extension average power (p > 0.05). There were significant correlations between all EI variables, 1RM, PT, and RTD at 0.2 s (p ≤ 0.05), but only vastus medialis EI and QEI were correlated to RTD at 0.05 s (p ≤ 0.05). The results of the present study suggest that QEI is related to muscular power and functional capacity of older subjects, but the EI of some individual quadriceps portions may underestimate the correlations with muscular performance.


Assuntos
Envelhecimento/fisiologia , Tolerância ao Exercício/fisiologia , Contração Isométrica/fisiologia , Força Muscular/fisiologia , Músculo Quadríceps/fisiologia , Idoso , Voluntários Saudáveis , Humanos , Joelho/fisiologia , Masculino , Torque
12.
J Hum Kinet ; 44: 171-81, 2014 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-25713678

RESUMO

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.

13.
Rev. bras. cineantropom. desempenho hum ; 13(6): 429-435, nov.-dez. 2011. ilus
Artigo em Português | LILACS | ID: lil-606692

RESUMO

O objetivo deste estudo foi comparar a força isométrica máxima (FIM) e a atividade elétrica dos músculos vasto medial (VM), vasto lateral (VL), reto femoral (RF), glúteo máximo (GM) e bíceps femoral (BF) entre contrações isométricas voluntárias máximas (CIVM) executadas em diferentes posições articulares e identificar as mais adequadas para normalizar o sinal de eletromiografia (EMG) de cada um dos músculos referidos, quando estes são ativados em condições dinâmicas. A amostra foi constituída de 10 indivíduos do sexo masculino, com idades entre 20 e 30 anos, familiarizados com treinamento de força. Foram realizadas CIVMs em diferentes ângulos articulares para os grupos extensores e flexores do joelho (0°, 60°, 90°) e extensores (-30°, 0°, 60°) e flexores do quadril (90°, 120°). Sobre a FIM foram encontrados valores significativamente diferentes entre as posições em 60° para flexão de joelhos e para extensão de joelhos em 60° e 90° (p<0,01) e não houve diferenças significativas entre as posições na flexão e extensão do quadril (p>0,05). Em relação ao sinal EMG, foram encontrados valores significativamente diferentes entre os ângulos para a extensão de joelhos somente no RF em 90° (p<0,01). Para a flexão de joelhos, flexão e extensão de quadril não foram encontradas diferenças siginificativas entre os músculos nos diferentes ângulos avaliados (p>0,05). Estes resultados sugerem que a posição de 60° é a mais adequada para avaliação dos flexores e extensores do joelho e que todas posições testadas neste estudo apresentam-se como adequadas para a avaliação da flexão e extensão de quadril.


The aim of this study was to compare maximal isometric force (MIF) and the electrical activity of the vastus medialis, vastus lateralis, rectus femoris, gluteus maximus and biceps femoris long head muscles between maximal voluntary contractions (MVC) performed at different joint angles, and to identify the most suitable positions to normalize the electromyography (EMG) signals from each of these muscles when they are activated under dynamic conditions. Ten men ranging in age from 20 to 30 years, who were familiar with strength training exercise, were studied. MVC at different joint angles of the knee extensors and flexors (0°, 60°, 90°) and hip extensors (-30°, 0°, 60°) and flexors (90°, 120°) were tested. The MIF values differed significantly between the 60° knee flexion and 60° and 90° knee extension positions (p<0.01). The same was not observed for hip flexion or extension (p>0.05). Significantly higher EMG values were only observed for the rectus femoris muscle at 90° knee extension (p<0.01). No differences between muscles were found for knee flexion, hip flexion or hip extension at the joint angles tested (p>0.05). These results suggest that the 60° knee joint flexion position is the most suitable for assessment of knee extension and flexion MIF, and that all positions tested in this study are suitable for the assessment of hip flexion and extension.

14.
Cell Biochem Funct ; 29(7): 534-42, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21780310

RESUMO

The vascular endothelium plays a key role in arterial wall homeostasis by preventing atherosclerotic plaque formation. A primary causal factor of endothelial dysfunction is the reactive oxygen species. Aerobic exercise is ascribed as an important adjuvant therapy in endothelium-dependent cardiovascular disease. However, little is known about the effects of concurrent (aerobic + strength) training on that. For a comparison of the effects of aerobic and concurrent physical training on endothelial function, oxidative stress parameters and the immunoinflammatory activity of monocytes/macrophages, 20 adult male volunteers of middle age were divided into a concurrent training (CT) programme group and an aerobic training group. The glutathione disulphide to glutathione ratio (GSSG/GSH) and plasma lipoperoxide (LPO) levels, as well as flow-mediated dilation (FMD), monocyte/macrophage functional activity (zymosan phagocytosis), body lipid profiles, aerobic capacity (maximal oxygen uptake) and strength parameters (one-repetition maximum test), were measured before and after the exercise training programmes. The CT exhibited reduced acute effects of exercise on the GSSG/GSH ratio, plasma LPO levels and zymosan phagocytosis. The CT also displayed improved lipid profiles, glycaemic control, maximal oxygen uptake and one-repetition maximum test values. In both the aerobic training and the CT, training improved the acute responses to exercise, as inferred from a decrease in the GSSG/GSH ratios. The aerobic sessions did not alter basal levels of plasma LPO or macrophage phagocytic activity but improved FMD values as well as lipid profiles and glycaemic control. In summary, both training programmes improve systemic redox status and antioxidant defences. However, the aerobic training was more efficient in improving FMD in the individuals studied.


Assuntos
Endotélio Vascular/fisiologia , Exercício Físico/fisiologia , Macrófagos/imunologia , Estresse Oxidativo , Fagocitose , Comportamento Sedentário , Antropometria , Biomarcadores/sangue , Artéria Braquial/diagnóstico por imagem , Artéria Braquial/fisiologia , Dissulfeto de Glutationa/sangue , Humanos , Peróxidos Lipídicos/sangue , Macrófagos/metabolismo , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Resistência Física , Fatores de Tempo , Ultrassonografia , Zimosan/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...