The Influence of Hip and Knee Joint Angles on Quadriceps Muscle-Tendon Unit Properties during Maximal Voluntary Isometric Contraction.

Determining how the quadriceps femoris musculotendinous unit functions, according to hip and knee joint angles, may help with clinical decisions when prescribing knee extension exercises. We aimed to determine the effect of hip and knee joint angles on structure and neuromuscular functioning of all constituents of the quadriceps femoris and patellar tendon properties. Twenty young males were evaluated in four positions: seated and supine in both 20° and 60° of knee flexion (SIT20, SIT60, SUP20, and SUP60). Peak knee extension torque was determined during maximal voluntary isometric contraction (MVIC). Ultrasound imaging was used at rest and during MVIC to characterize quadriceps femoris muscle and tendon aponeurosis complex stiffness. We found that peak torque and neuromuscular efficiency were higher for SUP60 and SIT60 compared to SUP20 and SIT20 position. We found higher fascicle length and lower pennation angle in positions with the knee flexed at 60°. The tendon aponeurosis complex stiffness, tendon force, stiffness, stress, and Young's modulus seemed greater in more elongated positions (60°) than in shortened positions (20°). In conclusion, clinicians should consider positioning at 60° of knee flexion rather than 20°, regardless if seated or supine, during rehabilitation to load the musculotendinous unit enough to stimulate a cellular response.

Exploring Acute Changes in Hamstring EMG after Warm-up and Stretching Using a Multifractal Analysis.

INTRODUCTION: This study aimed to apply multifractal detrended fluctuation analysis (MFDFA) to surface EMG to detect neuromuscular changes after realistic warm-up procedures that was followed by various stretching exercises. METHODS: Sixteen volunteers conducted two experimental sessions. Testing included two maximal voluntary contractions before, after a standardized warm-up, and after a stretching exercise (static or neurodynamic nerve gliding technique). EMG was registered on biceps femoris and semitendinosus muscles. EMG was analyzed using different parameters obtained from the singularity Hurst exponent function and multifractal power spectrum (both obtained from the multifractal detrended fluctuation analysis). RESULTS: The Hurst exponent, α maximum, and peak value of the multifractal spectrum significantly decreased after warm-up as compared with baseline for both biceps femoris ( P = 0.003, P = 0.006, and P = 0.003, respectively) and semitendinosus ( P = 0.006, P = 0.013 and P = 0.01, respectively) muscles. No further alteration was obtained after static or neurodynamic nerve gliding stretching as compared with post-warm-up ( P = 1.0). No significant difference was obtained for Hurst exponent range, width, and asymmetry of the multifractal spectrum ( P > 0.05). CONCLUSIONS: From the present results, EMG depicted multifractal features sensitive to detect neuromuscular changes after a warm-up procedure. An increase in multiscale complexity is revealed after warm-up without any further alteration after stretching. The multifractal spectrum depicted dominant small fluctuations that shifted toward slightly larger fluctuations that could be attributed to motor unit recruitment.

Concurrent Achilles tendon vibration and tibial nerve stimulation to estimate persistent inward current strength in motoneurons.

Vibratory (Tvib) and sustained (Tsust) torque responses to concurrent Achilles tendon vibration and neuromuscular electrical stimulation applied over the muscle belly (vib+stim) are used as indicators of motoneuron facilitation and, theoretically, persistent inward current strength. However, neuromuscular electrical stimulation (NMES) applied to the nerve trunk may potentiate motoneuronal excitability more than muscle belly NMES, yet it remains unclear whether NMES applied over the nerve evokes robust Tvib and Tsust responses when used during the vib+stim protocol. This study tested whether a nerve-targeted vib+stim protocol elicits Tvib and Tsust responses in the ankle plantar flexors with acceptable intra- and inter-session reliability. Fifteen men performed the vib+stim protocol with NMES applied over the tibial nerve three times across two sessions; twice in a single session (5-min apart) to test intrasession reliability and then again after 48 h to test intersession reliability. Intraclass correlation coefficients (ICC3,1), within-participant coefficients of variation (CV) and pairwise comparisons were used to verify relative and absolute reliability as well as systematic bias. Thirteen men presented Tvib and Tsust responses (response rate of 87%). Intrasession Tvib and Tsust ICCs were >0.73 but inter-session ICCs were <0.5. Although no systematic bias was detected (p>0.05), both intra- and inter-session CVs were large (>10%) for Tvib and Tsust. The Vib+stim protocol with NMES applied over the nerve evoked Tvib and Tsust in almost all participants, but presented a large intra- and inter-session variability. The method does not appear to be effective for assessing motoneuron facilitation in the plantar flexors.

Acute effects of dynamic stretching on neuromechanical properties: an interaction between stretching, contraction, and movement.

PURPOSE: The present study aimed to investigate the acute effects of dynamic stretching on neurophysiological and mechanical properties of plantar flexor muscles and to test the hypothesis that dynamic stretching resulted from an interaction between stretching, movement, and contraction. METHODS: The dynamic stretching conditioning activity (DS) was compared to static stretching (SS), passive cyclic stretching (PCS), isometric contractions (IC), static stretching followed by isometric contractions (SSIC), and control (CO) conditions. Stretching amplitude (DS, SS, PCS and SSIC), contraction intensity (DS, IC and SSIC) and duration (all 6 conditions) were matched. Thirteen volunteers were included. Passive torque, fascicle length, and stiffness were evaluated from a dynamometer and ultrasonography during passive dorsiflexion. Neuromuscular electrical stimulation was used to investigate contractile properties [peak twitch torque (PTT), and rate of torque development (RTD)] and muscle voluntary activation (%VA). Gastrocnemius lateralis electromyographic activity (GL EMG/Mwave) was obtained during maximal voluntary contraction. All of these parameters were measured immediately before and 10 s after each experimental condition. RESULTS: Peak twitch torque, RTD, %VA, GL EMG/Mwave remained unaltered, while passive torque was significantly reduced after DS (- 8.14 ± 2.21%). SS decreased GL EMG/Mwave (- 7.83 ± 12.01%) and passive torque (- 2.16 ± 7.25%). PCS decreased PTT (- 3.40 ± 6.03%), RTD (- 2.96 ± 5.16%), and passive torque (- 2.16 ± 2.05%). IC decreased passive torque (- 7.72 ± 1.97%) and enhanced PTT (+ 5.77 ± 5.19%) and RTD (+ 7.36 ± 8.35%). However, SSIC attenuated PTT and RTD improvements as compared to IC. CONCLUSION: These results suggested that dynamic stretching is multi-component and would result from an interaction between stretching, contraction, and movement.

Can Hip Joint Position affect Quadriceps Muscle Responses during Knee Extension Exercise?

This study investigated the acute effects of seated and supine knee extension exercise on muscle swelling, torque, and work output. Twelve resistance-trained men performed two isokinetic concentric-only knee-extension training protocols at different hip positions in a counter-balanced order. They completed the knee extension exercise in the seated (hip angle at 85°) and supine (hip angle at 180°) positions. The torque and work output were assessed during each set. Moreover, muscle thickness of the middle and proximal vastus lateralis and rectus femoris were evaluated before and after each protocol and used as an indicator of muscle swelling. Middle rectus femoris and proximal vastus lateralis thickness increased significantly (p=0.01) with no difference between exercise variations. However, the middle vastus lateralis thickness increased (p=0.01) only after the seated knee extension exercise (~7%). Knee extensors' peak torque and work output were approximately 8% higher (p=0.04) in the seated when compared to the supine hip position. There was a similar decrease in torque and work output throughout both protocols (p=0.98). In conclusion, seated knee extension exercises produced greater torque, work output, and muscle swelling in the vastus lateralis when compared to the supine knee extension exercise.

Effects of blood flow restriction exercise on hemostasis: a systematic review of randomized and non-randomized trials.

BACKGROUND: Blood flow restriction (BFR) exercise has shown to induce a positive influence on bone metabolism and attenuate muscle strength loss and atrophy in subjects suffering from musculoskeletal weakness. Despite the known benefits of BFR exercise, it remains unclear whether or not the pressurization of blood vessels damages the endothelial cells or increases risk for formation of thrombi. Thus, the effects of BFR exercise on coagulation, fibrinolysis, or hemostasis, remains speculative. OBJECTIVE: The aim of the present study was to perform a systematic review of the short and long- term effects of BFR exercise on blood hemostasis in healthy individuals and patients with known disease (ie, hypertension, diabetes, obesity, and ischemic heart disease). DATA SOURCES: A systematic review of English and non-English articles was conducted across PubMed, Science Direct, and Google Scholar databases, including reference lists of relevant papers. Study quality assessment was evaluated using the modified version of Downs and Black checklist. Search results were limited to exercise training studies investigating the effects of BFR exercise on blood hemostasis in healthy individuals and patients with disease. Level of evidence was determined according to the criteria described by Oxford Center for Evidence-Based Medicine. STUDY SELECTION: Only randomized controlled trials (RCTs) and non-randomized controlled trials (NRCTs) that examined the effects of exercise with BFR exercise vs exercises without BFR on blood hemostasis in healthy individuals and patients were included. DATA EXTRACTION: Nine studies were eligible (RCT =4; NRCT =5). RESULTS: The average score on the Downs and Black checklist was 11.22. All studies were classified as having poor methodological quality wherein the level of evidence provided in all reviewed studies was level IIb only (ie, poor quality RCTs). CONCLUSION: Considering the limitations in the available evidence, firm recommendations cannot be provided.

Could inter-set stretching increase acute neuromuscular and metabolic responses during resistance exercise?

This study investigated the acute effects of inter-set static stretching (ISS) during resistance exercise (RE) on the subsequent neuromuscular and metabolic responses. Twelve resistance-trained men performed three different knee extension RE protocols comprised of seven sets of 10 repetitions in a counterbalanced fashion. The three protocols were: 1) ISS (subjects performed 25 sec of quadriceps stretching between sets during 40 sec rest interval); 2) control (CON, subject passively rested between sets for 40 sec); 3) traditional (TRA, subject passively rested between sets for 120 sec). Total work was lower (p < 0.05) in ISS than CON and TRA (p <0.05). The fatigue index was greater (p < 0.05) in ISS compared with CON and TRA. ISS also resulted in lower (p < 0.05) electromyography (EMG) amplitude during the 6th and 7th sets compared with TRA. Additionally, EMG frequency was lower (p < 0.05) from the 3rd to 5th sets during ISS compared to CON, and from the 3rd to 7th sets compared to TRA. Muscle swelling and blood lactate similarly increased (p > 0.05) in response to all protocols. These results indicate that ISS negatively impacts neuromuscular performance, and does not increase the metabolic stress compared to passive rest intervals.

New insights for statistical analysis of blood pressure response to resistance training in elderly hypertensive women / Novas perpectivas para a análise estatística da resposta da pressão arterial ao treinamento resistido em mulheres idosas hipertensas

ABSTRACT The main goal was to present statistical procedures for a better data interpretation of responsiveness, explain how to deal with RTM effect, and describe how to determine clinically important changes in BP from significant real difference (SRD). Twenty-seven hypertensive elderly women were included, and RT consisted of a periodized linear model. The RT lasted 10 weeks, with two sessions performed per week. Responders were classified on the basis of SBP differences between time-points T1 (first 3 weeks) and T4 (weeks 9-10). Statistical analyses were performed using One-Way Repeated Measures ANOVA, an analysis of covariance (ANCOVA), the linear mixed model (LMM) was used in the present study, and SRD was also calculated. In conclusion, when one-way repeated measure ANOVA was conducted to determine whether there was a statistically significant difference in SBP levels over the course of 10-week RT, results showed a non-significant reduction of -2.24 mmHg, while classifying subjects by responsiveness provides a different perspective of the results. Furthermore, initial SBP was the more powerful predictor of post-exercise SBP response, as analyzed by the regression to the mean effect. Finally, the reductions of -2.24 mmHg was not statistically significant nor clinically meaningful, but fell within the measurement error of the SBP measurements.

RESUMO O objetivo principal do estudo foi apresentar procedimentos estatísticos para uma melhor interpretação dos dados sobre a responsividade, explicar como lidar com o efeito da regressão a média (RM) e descrever como determinar alterações clinicamente importantes na pressão arterial (PA) pelo cálculo da diferença clínica (DC). Vinte e sete mulheres idosas hipertensas foram incluídas e o treinamento resistido (TR) consistiu em um modelo linear periodizado. O TR durou 10 semanas, com duas sessões realizadas por semana. Os responsivos foram classificados com base nas diferenças da pressão arterial sistólica (PAS) entre os momentos T1 (primeiras 3 semanas) e T4 (semanas 9-10). As análises estatísticas no presente estudo foram realizadas utilizando a ANOVA de medidas repetidas, análise de covariância (ANCOVA) e modelo linear misto (MLM). Conclui-se que quando uma ANOVA de medidas repetidas é aplicada, os resultados mostram uma redução não significativa de -2,24 mmHg, mas a classificação dos participantes por responsividade fornece uma interpretação diferente dos resultados. Além disso, a PAS inicial foi o preditor mais potente da resposta pós-exercício da PAS, conforme analisado pela RM. Finalmente, as reduções de -2,24 mmHg não foram estatisticamente significativas e nem clinicamente importantes, mas caíram dentro do erro de medida.

The impact of sarcopenic obesity on inflammation, lean body mass, and muscle strength in elderly women.

OBJECTIVE: The objective of this study was to apply the newly standardized definition for sarcopenia from the Foundation for the National Institutes of Health (FNIH) and the current definition for obesity to 1) determine the prevalence of sarcopenic obesity (SO) in obese elderly women; 2) compare the muscle strength, lean body mass, and markers of inflammation between obese elderly women with SO and nonsarcopenic obesity (NSO), and 3) elucidate the relationship between appendicular lean mass adjusted for body mass index (aLM/BMI) with muscle strength, lean body mass, and obesity indices. METHODS: A total of 64 elderly obese women (age: 68.35±6.04 years) underwent body composition analysis by dual-energy X-ray absorptiometry. Participants were classified into two groups according to the definition of SO and NSO. Blood samples were collected for total cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein, uric acid, urea, interleukin-6 (IL-6), glucose, and creatine kinase (CK) measurements. RESULTS: The SO group presented a significantly greater BMI, fat (%), glucose, a marginal trend toward significance for uric acid, and IL-6 compared to the NSO group. In addition, the SO group displayed lower values for muscle strength and lean body mass. From a correlation standpoint, a higher aLM/BMI was positively associated with lean body mass and muscle strength and negatively associated with a lower BMI and percentage body fat. CONCLUSION: The definition criteria from FNIH and obesity permit the ability to illustrate the prevalence and identify SO in elderly women with low muscle mass, low muscle strength, and impaired markers of inflammation.

Resistance training-induced gains in muscle strength, body composition, and functional capacity are attenuated in elderly women with sarcopenic obesity.

OBJECTIVES: The purpose of this study was to compare the effects of resistance training (RT) on body composition, muscle strength, and functional capacity in elderly women with and without sarcopenic obesity (SO). METHODS: A total of 49 women (aged ≥60 years) were divided in two groups: without SO (non-SO, n=41) and with SO (n=8). Both groups performed a periodized RT program consisting of two weekly sessions for 16 weeks. All measures were assessed at baseline and postintervention, including anthropometry and body composition (dual-energy X-ray absorptiometry), muscle strength (one repetition maximum) for chest press and 45° leg press, and functional capacity (stand up, elbow flexion, timed "up and go"). RESULTS: After the intervention, only the non-SO group presented significant reductions in percentage body fat (-2.2%; P=0.006), waist circumference (-2.7%; P=0.01), waist-to-hip ratio (-2.3; P=0.02), and neck circumference (-1.8%; P=0.03) as compared with baseline. Muscle strength in the chest press and biceps curl increased in non-SO only (12.9% and 11.3%, respectively), while 45° leg press strength increased in non-SO (50.3%) and SO (40.5%) as compared with baseline. Performance in the chair stand up and timed "up and go" improved in non-SO only (21.4% and -8.4%, respectively), whereas elbow flexion performance increased in non-SO (23.8%) and SO (21.4%). Effect sizes for motor tests were of higher magnitude in the non-SO group, and in general, considered "moderate" compared to "trivial" in the SO group. CONCLUSION: Results suggest that adaptations induced by 16 weeks of RT are attenuated in elderly woman with SO, compromising improvements in adiposity indices and gains in muscle strength and functional capacity.

Effects of Resistance Training Volume on MMPs in Circulation, Muscle and Adipose Tissue.

The aim of this study was to investigate the effects of different resistance training (RT) volumes on MMP activity in skeletal muscle, visceral adipose tissue and circulation. 21 Wistar rats were randomly divided into 3 groups (n=7 per group): sedentary control (SC); RT with 4 ladder climbs (RT-4; 50, 75, 90 and 100% of their maximal carrying capacity) and RT with 8 ladder climbs (RT-8 with 2 sets for each load). The 8-week RT consisted of climbing a 1.1-m vertical ladder with weights secured to the animals' tails. MMP-2 and -9 activity were analyzed by zymography. RT-8 displayed higher active MMP-2 activity as compared with SC and RT-4 in skeletal muscle (p<0.05). There was no significant difference between groups for pro and intermediate-MMP-2 activity in visceral adipose tissue, while RT-8 presented lower active MMP-2 activity as compared with SC (p<0.05). Plasma pro and active MMP-2 and MMP-9 activity was lower in RT-8 as compared with RT-4 (p<0.05). These results suggest that higher volume RT up-regulates MMP-2 activity in skeletal muscle, while down-regulating MMP-2 in visceral adipose tissue. Moreover, it induces a decrease of MMP-2, 9 activity in circulation. Different tissue and circulatory MMP responses to RT may result in specific remodeling.

Risco de quedas e sua relação com a funcionalidade e medo de cair em idosas / Risk of falls and the relationship with the functionality and fear of falling in the older women

O objetivo principal desta pesquisa foi de analisar a relação das medidas relativas ao risco de quedas, capacidade funcional, força muscular e medo de cair em mulheres idosas caidoras e não caidoras. O objetivo secundário foi de analisar a relação da faixa etária com as medidas analisadas. Para tanto, foi realizado um estudo transversal com 53 idosas (idade entre 60 a 80 anos) residentes na comunidade. As voluntárias da pesquisa foram avaliadas quanto ao risco de quedas (Escala de Equilíbrio de Berg ­ EEB; Teste de Alcance Funcional ­ TAF; Teste de Alcance Lateral ­ TAL; e Timed Up and Go ­ TUG), capacidade funcional (Teste de Caminhada de 6 Minutos ­ TC6'; Teste de Sentar e Levantar ­ Snt Lev; Teste de Flexão de Cúbitos ­ Flx Cub; e Teste de Sentar e Alcançar ­ Snt e Alc), força muscular máxima (Leg Press, Supino e Rosca Direta) e medo de cair (FES-I). Após a análise de normalidade (Shapiro-Wilk) foram realizadas análises comparativas (caidoras vs não-caidoras) e de correlação entre as variáveis medidas. Também foi realizada análise comparativa entre as diferentes faixas etárias (60 a 69 anos vs 70 a 80 anos). O nível de significância foi adotado quando α ≤ 0,05. Não foram observadas diferenças entre o grupo de caidoras e não caidoras quanto às variáveis analisadas (P > 0,05). Foram observadas correlações significativas (p < 0,05) e moderadas (±0,5 < r ≤ ±0,7) entre a idade e Rosca Direta (r = - 0,52), idade e EEB (r = - 0,52, TUG e TC6' (r = -0,55). As idosas de faixa etária entre 70 e 80 apresentaram piores desempenhos nos testes de EEB, TUG, TC6', Leg Press e Rosca Direta quando comparada com as idosas da faixa etária entre 60 e 69 anos (P < 0 ,05). Conclui-se, portanto, que apesar de não ter havido diferença entre os grupos de caidoras e não caidoras, pôde-se observar correlação das medidas relativas ao risco de quedas, capacidade funcional e força muscular. A idade foi um fator de influência para o risco de quedas, capacidade funcional e força, e não para o medo de cair.(AU)

The main aim of this research was to examine the measures the relationship between risk of accident falls, functional capacity, muscle strength and fear of fall in fallers and non-fallers older women. The secondary objective was to analyze the relationship between age with the analyzed outcomes. A crosssectional study was conducted with 53 community-dwelling older women (age:60-80 years). The risk of falls (Berg Balance Scale - EEB; Functional Reach - TAF; Side Reach - TAL, and Timed Up and Go - TUG), functional capacity (6 Minutes Walk Test ­ TC6'; Chair Stand Test - Snt Lev; Arm Curl Test - Flx Cub, and Sit-and-reach Test ­ Snt Alc), maximal muscle strength (Leg press, Bench press and Standing Arm Curl) and fear of fall (FES-I) were evaluated in volunteers. After Shapiro-Wilk Test, we performed a comparative analyzes (fallers vs non-fallers) and correlation between measured variables. It was also performed a comparative analysis between different age groups (60 to 69 years vs 70-80 years). Statistical significance was accepted as P < 0.05. There were no differences between the fallers and non-fallers group in analyzed outcomes measures (P > 0.05). Were observed significant (P < 0.05) and moderate (± 0.5

Endothelial nitric oxide synthase Glu298Asp gene polymorphism influences body composition and biochemical parameters but not the nitric oxide response to eccentric resistance exercise in elderly obese women.

Both endothelial nitric oxide synthase (eNOS) gene polymorphism and nitric oxide (NO) are involved in important cardiovascular, muscular and inflammatory physiological mechanisms during ageing and response to exercise. The aim of this study was to investigate the NO kinetic response following an acute eccentric resistance exercise (ERE) session and the possible effect of the Glu298Asp eNOS gene polymorphism in elderly obese women. Eighty-seven women (age 69·4 ± 6·1 years, body weight 74·9 ± 12·7 kg, height 151·9 ± 6·0 cm and BMI 32·5 ± 5·7 kg m-2 ) completed seven sets of ten eccentric repetitions at 110% of the ten repetitions maximum (10RM). NO concentrations remained elevated up to 48 h following the acute ERE session as compared with baseline, for GG and GT/TT groups (P<0·05), with no differences between genotypes. The GG genotype group had higher body weight, prevalence of obesity (BMI classification - 81% versus 56%), BMI and higher relative muscle strength, while they had significantly lower triglycerides, VLDL and urea concentrations as compared with TT/TG group. In conclusion, NO remains elevated for up to 48 h after an acute ERE session, without genotype interaction. The TT/TG genotype had a negative impact on triglycerides, VLDL and urea concentrations. Thus, T carriers should increase their attention to cardiovascular risk factor and metabolic disorders.

Understanding the individual responsiveness to resistance training periodization.

This study was designed to compare the effects of linear periodization (LP) and undulating periodization (UP) on functional capacity, neuromuscular function, body composition, and cytokines in elderly sedentary women. We also aimed to identify the presence of high responders (HR), medium responders (MR), and low responders (LR) for irisin, interleukin-1 beta (IL-1ß), toll-like receptor-4 (TLR-4), and brain-derived neurotrophic factor (BDNF) to resistance training (RT). Forty-nine elderly women were assigned to a control group, LP, and UP scheme. Functional capacity, body composition, maximal strength, irisin, TLR-4, BDNF, and IL-1ß were evaluated. Both periodization models were effective in improving 45° leg press 1RM, chair-stand, arm curl, and time-up and go tests, with no significant differences in body composition and cytokines. Furthermore, HR, MR, and LR were identified for irisin, IL-1ß, TLR-4, and BDNF, with differences between groups and moments. This study provides evidence that both periodization models were effective in improving functional capacity and neuromuscular function, with no effect on body composition and cytokines (probably as a consequence of the different responsiveness). Furthermore, for the first time, HR, MR, and LR were identified for irisin, IL1-ß, TLR-4, and BDNF in response to RT.

Classification of pro-inflammatory status for interleukin-6 affects relative muscle strength in obese elderly women.

BACKGROUND: Obesity, defined by an excess amount of body fat or a percent body fat higher than 30 % for women is a complex chronic disorder with multifactorial etiology and is accompanied by chronic low-grade inflammation, which results in elevated pro-inflammatory cytokines. AIMS: The aim of this study was to compare muscle strength between high and low pro-inflammatory status in obese elderly women and to verify the relationship of IL-6 with muscle strength and fat-free mass. METHODS: Eighty-nine elderly women (age 69.47 ± 6.07 years; body mass 64.70 ± 12.04 kg; height 1.52 ± 0.06 m; body mass index 27.78 ± 4.75 kg/m(2)) were divided into two groups: high and low inflammatory status for IL-6. Lower limb muscle strength was tested using bilateral leg extension with the ten repetitions maximum test, IL-6 was measured by ELISA and body composition by dual-energy X-ray absorptiometry. RESULTS: Women classified from the high pro-inflammatory status presented lower relative muscle strength (P = 0.056) when compared with the low inflammatory status group, with no differences for absolute muscle strength (P = 0.18). There was a significant negative correlation of IL-6 with relative muscle strength (P = 0.03, R = -0.22) and a considerable trend toward significance (P = 0.06, R = -0.19) and negative association with fat-free mass (P = 0.84, R = -0.02). CONCLUSIONS: This study provides insights that a high pro-inflammatory status in sedentary obese elderly women might impair muscle strength and negatively affect fat-free mass. Thus, elderly women classified with high pro-inflammatory status for IL-6 should receive further health care attention to prevent this deleterious condition.

Identification of high responders for interleukin-6 and creatine kinase following acute eccentric resistance exercise in elderly obese women.

OBJECTIVES: Resistance exercise is used as a non-pharmacological tool to elicit both gains in and maintenance of physical function in the elderly. Thus, the present study examined the acute response of creatine kinase and interleukin-6 following an eccentric resistance exercise session in elderly obese women classified as high responders or normal responders. DESIGN: Cross-sectional field study. METHODS: Ninety elderly obese women (69.4 ± 6.01 years) were tested for a 10 repetition maximum on the leg extension exercise and then completed an acute eccentric resistance exercise session consisting of seven sets of 10 repetitions at 110% of 10 repetition maximum with a rest of 3 min between sets. Subjects were divided into normal response or high response on the basis of the peak serum interleukin-6 (NR = 59 and HR = 7) and creatine kinase (NR = 81 and HR = 9) concentration being greater than (HR) or less than (NR) the 90th percentile. RESULTS: Creatine kinase was higher at 0 h, 3h, 24h and 48 h following the ERE for the HR group. The peak creatine kinase was significantly higher in HR group versus the normal response group. The average increase in the serum interleukin-6 Δ for the HR group (∼ 850%) was significantly higher versus the normal response group (∼ 55%). Serum interleukin-6 was significantly higher at 0 h and 24h following eccentric resistance exercise only for the high response group, while peak levels were significantly higher in high response group versus the normal response group (p ≤ 0.005). Only one subject met the criteria to be classified as high response for both creatine kinase and interleukin-6 responsiveness. CONCLUSIONS: Elderly individuals classified as high response experienced greater creatine kinase and interleukin-6 responses to ERE. Thus, a prudent approach for eccentric resistance exercise prescription might be programming additional recovery days and/or lower intensity training, especially in the beginning stages of a program.

Comparação da força muscular entre mulheres de meia idade com e sem sobrepeso/obesidade / Comparison of muscle strenght between middle-aged women with and without overweight/obesity

A obesidade é atualmente um dos maiores problemas de saúde pública em países desenvolvidos e em desenvolvimento. Apesar de a redução da força muscular estar fortemente associada à doenças cardiovasculares, poucos estudos analisaram a força muscular relativa em mulheres com e sem sobrepeso e obesidade. O presente estudo teve como objetivo comparar a força muscular absoluta e relativa de mulheres de meia idade com e sem sobrepeso e obesidade, além de correlacionar a força muscular relativa com o índice de massa corporal (IMC), com a circunferência da cintura (CC) e com a razão cintura-estatura (RCE). A hipótese inicial era de que mulheres com sobrepeso e obesidade apresentariam menores valores de força muscular relativa. Foram avaliadas 20 mulheres obesas (36,7 ± 7,9 anos; 33,4 ± 2,4 kg/m2), 46 sobrepesadas (34,8 ± 7,8 anos; 27,7 ± 1,2 kg/m2) e 53 eutróficas (33,2 ± 9,3anos; 22,3 ± 1,7 kg/m2). A classificação de sobrepeso (IMC > 25 < 29,9 kg/m2) e obesidade (IMC > 30 kg/m2) foi definida de acordo com a Organização Mundial de Saúde. A força muscular relativa [força absoluta (kg)/massa corporal (kg)] foi mensurada por meio do teste de preensão manual. A força muscular relativa foi respectivamente menor nas mulheres com obesidade e sobrepeso quando comparado as mulheres eutróficas (0,35 ± 0,05 vs 0,42 ± 0,06 vs 0,48 ± 0,08; P=0,001). Houve uma relação negativa do IMC (r=-0,60; P=0,001), CC (r=-0,45; P=0,001) e RCE (r=-0,41; P=0,001) com a forca muscular relativa. A redução da força muscular relativa é um aspecto característico de mulheres com sobrepeso e obesidade.

Obesity is currently one of the major public health problems in developed and developing countries. Although the decrease in muscle strength is highly associated with cardiovascular diseases, few studies analyzed the relative muscle strength in women with and without overweight and obesity. The present study aimed to compare absolute and relative muscle strength of middle-aged women with and without overweight and obesity, as well as, to correlate relative muscle strength with body mass index (BMI), waits circumference (WC) and waist-to-height ratio (WHR). The initial hypothesis was that overweight and obese women would present lower values of relative muscle strength. Twenty obese (36.7 ± 7.9 years; 33.4 ± 2.4 kg/m2), 46 overweight (34.8 ± 7.8 years; 27.7 ± 1.2 kg/m2) and 53 eutrophic women (33.2 ± 9.3 years; 22.3 ± 1.7 kg/m2) were evaluated. The cut-off point for overweight (IMC > 25 < 29.9 kg/m2) and obesity (IMC > 30 kg/m2) was defined according to the World Health Organization. Relative muscle strength [absolute strength (kg)/body mass (kg)] was measured by the handgrip test. Relative muscle strength was lower for women with obesity and overweight as compared with eutrophic women (0.35 ± 0.05 vs 0.42 ± 0.06 vs 0.48 ± 0.08; P=0.001), respectively. There was a negative correlation of BMI (r=-0.60; P=0.001), WC (r=-0.45; P=0.001) and RCE (r=-0.41; P=0.001) with relative muscle strength. The reduction of relative muscle strength is a characteristic aspect of women with overweight and obesity.

Respostas da percepcao subjetiva de esforco em teste incremental de mulheres idosas sedentarias / Ratings of perceived exertion in an incremental test in elderly women

Apesar da percepção subjetiva de esforço (PSE) ser utilizada para a avaliação e prescrição de exercícios em idosos, alguns indivíduos podem apresentar dificuldades de entendimento a escala de Borg. Nesse sentido, o objetivo do estudo foi verificar se mulheres idosas percebem, associam e relatam alterações no esforço físico por meio da PSE, em resposta a um teste de esforço máximo, bem como se é possível predizer o ponto de compensação respiratória (PCR) pela escala de Borg. Vinte e seis mulheres idosas realizaram uma avaliação de esforço máximo em esteira com análise ergoespirométrica, eletrocardiográfica e PSE em protocolo de rampa. As respostas de PSE entre diferentes zonas de intensidade baixa, moderada e alta foram consideradas para avaliar a percepção, associação e relato de alterações no esforço. Oito voluntárias (30,77%) não perceberam, associaram e relataram alterações no esforço por meio da PSE. Naquelas que perceberam, associaram e relataram alterações no esforço, o percentual da potência máxima no momento da PSE 13 (69,92 ± 10,30) e 14 (78,90 ± 11,00) não diferiu significativamente do momento do PCR (75,45 ± 9,65). Por fim, conclui-se que mulheres idosas podem apresentar dificuldades em perceber, associar e relatar alterações no esforço por meio da escala de Borg. Contudo, naquelas que percebem, associam e relatam alterações no esforço por meio da escala de Borg, as PSE 13 e 14 coincidem com o PCR.

Although the rating of perceived exertion (RPE) is used in the evaluation and prescription of physical activity for the elderly, some subjects might find it hard tounderstand the Borg scale. This study aimed to verify whether elderly women could notice, associate, and report changes in physical effort using the perceived exertion scale in response to a stress test. We also aimed to verify the possibility of predicting a respiratory compensation point (RCP) using the Borg scale. Twenty six elderly women took a stress test on a treadmill, with ergospirometry and ECG monitoring and RPE in a ramp protocol. Based on the RPEs for different exercise intensities (low, moderate, high), we assessed the women's perception, association, and report of changes in physical effort. Eight subjects (30.77%) did not notice, associate or report changes in effort using RPE. For those who did, the percentage of maximum workload at the moment of RPE 13 (69.92 ± 10,30) and 14 (78.90 ± 11,00) did not differ significantly from the one at the moment of RCP (75.45 ± 9.65). We conclude that some elderly women may have difficulties noticing, associating and reporting changes in physical effort using the Borg scale. However, for those who do not have any difficulty, RPE 13 and 14 coincide with the RCP.

Resistance exercise leading to failure versus not to failure: effects on cardiovascular control.

BACKGROUND: The aim of the present study was to evaluate the acute effects of resistance exercise (RE) leading to failure and RE that was not to failure on 24 h blood pressure (BP) and heart rate variability (HRV) in sedentary normotensive adult women. METHODS: Ten women (33.2 ± 5.8 years; 159.3 ± 9.4 cm; 58.0 ±6.4 kg; body fat 28.4 ± 2.8%) randomly underwent three experimental sessions: control (40 minutes of seated rest), RE leading to failure with 3 sets of 10 repetitions maximum (10-RM), and RE not to failure at 60% of 10-RM with 3 sets of 10 repetitions. Immediately post session BP and HRV were measured for 24 h. RESULTS: Ratings of perceived exertion and heart rate were higher during the 10-RM session when compared with 60% of 10-RM (6.4 ± 0.5 vs 3.5 ± 0.8 and 123.7 ± 13.9 vs 104.5 ± 7.3 bpm, respectively). The systolic, diastolic and mean BP decreased at 07:00 a.m. after the 10-RM session when compared with the control session (-9.0 ± 7.8 mmHg, -16.0 ± 12.9 mmHg and -14.3 ± 11.2 mmHg, respectively). The root mean square of the squared differences between R-R intervals decreased after both the 60% of 10-RM and 10-RM sessions compared with the control session. CONCLUSIONS: An acute RE session leading to failure induced a higher drop of BP upon awakening, while both RE sessions reduced cardiac parasympathetic modulation. RE may be an interesting training strategy to acutely decrease BP in adult women.