Acute Effects of Breaking up Sitting Time With Isometric Wall Squat Exercise on Vascular Function and Blood Pressure in Sedentary Adults: Randomized Crossover Trial.

PURPOSE: The World Health Organization has recommended breaking up sitting time to improve cardiovascular health. However, whether isometric exercise can be effectively used as a strategy to break up sitting time remains unclear. Thus, the aim of this study was to analyze the acute effects of breaking up prolonged sitting with isometric wall squat exercise (IWSE) on vascular function and blood pressure (BP) in sedentary adults. METHODS: This randomized crossover trial included 17 adults (53% male, 26 ± 6 yr, 22.4 ± 3.6 kg/m2) with high sedentary behavior (≥ 6 hr/d). The participants completed 2 experimental sessions in a randomized order, both sharing a common sitting period of 180 min: Breaks (2-min breaks were incorporated into the IWSE, with participants maintaining their knees at the angle determined by the incremental test, which occurred every 30 min) and Control (sitting for 180 min continuously). Popliteal artery flow-mediated dilation (FMD) and brachial BP were measured before and at 10 and 30 min after the experimental sessions. RESULTS: The results did not indicate significant session vs time interaction effects on popliteal FMD and brachial BP (P > .05). A subanalysis including only participants with popliteal FMD reduction after the Control session (n = 11) revealed that Breaks enhanced popliteal FMD after 10 min (1.38 ± 6.45% vs -4.87 ± 2.95%, P= .002) and 30 min (-0.43 ± 2.48% vs -2.11 ± 5.22%, P= .047). CONCLUSION: Breaking up prolonged sitting with IWSE mitigates impaired vascular function resulting from prolonged sitting but has no effect on BP in sedentary adults.

Toward a Better Understanding of Muscle Microvascular Perfusion During Exercise in Patients With Peripheral Artery Disease: The Effect of Lower-Limb Revascularization.

PURPOSE: Leg muscle microvascular blood flow (perfusion) is impaired in response to maximal exercise in patients with peripheral artery disease (PAD); however, during submaximal exercise, microvascular perfusion is maintained due to a greater increase in microvascular blood volume compared with that seen in healthy adults. It is unclear whether this submaximal exercise response reflects a microvascular impairment, or whether it is a compensatory response for the limited conduit artery flow in PAD. Therefore, to clarify the role of conduit artery blood flow, we compared whole-limb blood flow and skeletal muscle microvascular perfusion responses with exercise in patients with PAD (n=9; 60±7 years) prior to, and following, lower-limb endovascular revascularization. MATERIALS AND METHODS: Microvascular perfusion (microvascular volume × flow velocity) of the medial gastrocnemius muscle was measured before and immediately after a 5 minute bout of submaximal intermittent isometric plantar-flexion exercise using contrast-enhanced ultrasound imaging. Exercise contraction-by-contraction whole-leg blood flow and vascular conductance were measured using strain-gauge plethysmography. RESULTS: With revascularization there was a significant increase in whole-leg blood flow and conductance during exercise (p<0.05). Exercise-induced muscle microvascular perfusion response did not change with revascularization (pre-revascularization: 3.19±2.32; post-revascularization: 3.89±1.67 aU.s-1; p=0.38). However, the parameters that determine microvascular perfusion changed, with a reduction in the microvascular volume response to exercise (pre-revascularization: 6.76±3.56; post-revascularization: 2.42±0.69 aU; p<0.01) and an increase in microvascular flow velocity (pre-revascularization: 0.25±0.13; post-revascularization: 0.59±0.25 s-1; p=0.02). CONCLUSION: These findings suggest that patients with PAD compensate for the conduit artery blood flow impairment with an increase in microvascular blood volume to maintain muscle perfusion during submaximal exercise. CLINICAL IMPACT: The findings from this study support the notion that the impairment in conduit artery blood flow in patients with PAD leads to compensatory changes in microvascular blood volume and flow velocity to maintain muscle microvascular perfusion during submaximal leg exercise. Moreover, this study demonstrates that these microvascular changes are reversed and become normalized with successful lower-limb endovascular revascularization.

Cerebrovascular function and its association with systemic artery function and stiffness in older adults with and without mild cognitive impairment.

PURPOSE: Our aim was to compare cerebrovascular and systemic vascular function between older adults with and without mild cognitive impairment (MCI), and to determine which measures of vascular function best predict the presence of MCI. METHODS: In 41 adults with MCI and 33 adults without MCI (control) we compared middle cerebral artery velocity (MCAv) and cerebrovascular pulsatility index (PI) at rest, cerebrovascular reactivity to CO2, and responsiveness to changes in blood pressure (%∆MCAv/%∆MAP). Systemic vascular function was assessed by flow-mediated dilation (FMD) and stiffness by pulse wave velocity (PWV). RESULTS: Cerebrovascular PI was higher in MCI compared with control (mean ± SD: 1.17 ± 0.27 vs. 1.04 ± 0.21), and MCI exhibited a lower %∆MCAv/%∆MAP (1.26 ± 0.44 vs. 1.50 ± 0.55%). Absolute (p = 0.76) and relative cerebrovascular reactivity to CO2 (p = 0.34) was similar between MCI and control. When age was included as a covariate the significant difference in cerebral PI between groups was lost. PWV was higher (13.2 ± 2.2 vs. 11.3 ± 2.5 m s-1) and FMD% (4.41 ± 1.70 vs. 5.43 ± 2.15%) was lower in MCI compared with control. FMD% was positively associated with PI across the cohort. Logistic regression analysis indicated that FMD and PWV significantly discriminated between MCI and controls, independent of age, whereas the inclusion of cerebrovascular measures did not improve the predictive accuracy of the model. CONCLUSION: These findings raise the possibility that early changes in systemic vascular stiffness and endothelial function may contribute to altered cerebrovascular haemodynamics and impaired cognitive function, and present potential targets for prevention and treatment strategies in people with MCI.

Effects of resistance training on endothelial function: A systematic review and meta-analysis.

BACKGROUND AND AIMS: The effects of resistance training on flow-mediated dilation (FMD), which has been the gold standard non-invasive assessment of endothelial function and is associated with the risk of cardiovascular events, are not well known. We conducted a systematic review to analyze the effects of resistance training on FMD. METHODS: We searched Pubmed, Embase, CINAHL, SPORTDiscuss, Scopus, Web of Science and PEDro databases for studies that met the following criteria: (a) randomized controlled trials of resistance exercise with a comparative non-exercise group or contralateral untrained limb in adults and/or elderly; (b) studies that measured post-occlusion brachial artery FMD by ultrasonography, before and after intervention. Mean differences (MDs) with 95 % confidence interval (95 % CI) were calculated using an inverse variance method with a random effects model. RESULTS: Twenty-three studies were included in the meta-analysis (n = 785 participants; 53 % females). Resistance training on FMD responses showed a favorable result for the resistance training group (n = 366) compared to the control group (n = 358) (MD 2.39, 95%CI 1.65, 3.14; p<0.00001). Subgroup analysis indicated favorable results for the dynamic resistance training (n = 545; MD 2.12, 95 % CI 1.26, 2.98; p<0.00001) and isometric handgrip training (n = 179; MD 3.32, 95 % CI 1.68, 4.96; p<0.0001) compared to the control group. The effect of resistance training on FMD responses was also favorable regardless of the condition of the participants (Healthy [n = 261]: MD 2.11, 95 % CI 1.04, 3.18; p<0.0001; Cardiovascular disease [n = 310]: MD 2.89, 95 % CI 0.88, 4.90; p = 0.005; metabolic disease [n = 153]: MD 2.40, 95 % CI 1.59, 3.21; p<0.00001). CONCLUSIONS: Resistance training improves FMD in healthy individuals and patients with cardiovascular and metabolic diseases.

Skeletal muscle microvascular perfusion responses to cuff occlusion and submaximal exercise assessed by contrast-enhanced ultrasound: The effect of age.

Impairments in skeletal muscle microvascular function are frequently reported in patients with various cardiometabolic conditions for which older age is a risk factor. Whether aging per se predisposes the skeletal muscle to microvascular dysfunction is unclear. We used contrast-enhanced ultrasound (CEU) to compare skeletal muscle microvascular perfusion responses to cuff occlusion and leg exercise between healthy young (n = 12, 26 ± 3 years) and older (n = 12, 68 ± 7 years) adults. Test-retest reliability of CEU perfusion parameters was also assessed. Microvascular perfusion (microvascular volume × flow velocity) of the medial gastrocnemius muscle was measured before and immediately after: (a) 5-min of thigh-cuff occlusion, and (b) 5-min of submaximal intermittent isometric plantar-flexion exercise (400 N) using CEU. Whole-leg blood flow was measured using strain-gauge plethysmography. Repeated measures were obtained with a 15-min interval, and averaged responses were used for comparisons between age groups. There were no differences in post-occlusion whole-leg blood flow and muscle microvascular perfusion between young and older participants (p > .05). Similarly, total whole-leg blood flow during exercise and post-exercise peak muscle microvascular perfusion did not differ between groups (p > .05). The overall level of agreement between the test-retest measures of calf muscle perfusion was excellent for measurements taken at rest (intraclass correlation coefficient [ICC] 0.85), and in response to cuff occlusion (ICC 0.89) and exercise (ICC 0.95). Our findings suggest that healthy aging does not affect muscle perfusion responses to cuff-occlusion and submaximal leg exercise. CEU muscle perfusion parameters measured in response to these provocation tests are highly reproducible in both young and older adults.

An Experimental Series Investigating the Effects of Hyperinsulinemic Euglycemia on Myocardial Blood Flow Reserve in Healthy Individuals and on Myocardial Perfusion Defect Size following ST-Segment Elevation Myocardial Infarction.

BACKGROUND: Incomplete restoration of myocardial blood flow (MBF) is reported in up to 30% of ST-segment elevation myocardial infarction (STEMI) despite prompt mechanical revascularization. Experimental hyperinsulinemic euglycemia (HE) increases MBF reserve (MBFR). If fully exploited, this effect may also improve MBF to ischemic myocardium. Using insulin-dextrose infusions to induce HE, we conducted four experiments to determine (1) how insulin infusion duration, dose, and presence of insulin resistance affect MBFR response; and (2) the effect of an insulin-dextrose infusion given immediately following revascularization of STEMI on myocardial perfusion. METHODS: The MBFR was determined using myocardial contrast echocardiography. Experiment 1 (insulin duration): 12 participants received an insulin-dextrose or saline infusion for 120 minutes. MBFR was measured at four time intervals during infusion. Experiment 2 (insulin dose): 22 participants received one of three insulin doses (0.5, 1.5, 3.0 mU/kg/minute) for 60 minutes. Baseline and 60-minute MBFRs were determined. Experiment 3 (insulin resistance): five metabolic syndrome and six type 2 diabetes (T2DM) participants received 1.5 mU/kg/minute of insulin-dextrose for 60 minutes. Baseline and 60-minute MBFRs were determined. Experiment 4 (STEMI): following revascularization for STEMI, 20 patients were randomized to receive either 1.5 mU/kg/minute insulin-dextrose infusion for 120 minutes or standard care. Myocardial contrast echocardiography was performed at four time intervals to quantify percentage contrast defect length. RESULTS: Experiment 1: MBFR increased with time through to 120 minutes in the insulin-dextrose group and did not change in controls. Experiment 2: compared with baseline, MBFR increased in the 1.5 (2.42 ± 0.39 to 3.25 ± 0.77, P = .002), did not change in the 0.5, and decreased in the 3.0 (2.64 ± 0.25 to 2.16 ± 0.33, P = .02) mU/kg/minute groups. Experiment 3: compared with baseline, MBFR increase was only borderline significant in metabolic syndrome and T2DM participants (1.98 ± 0.33 to 2.59 ± 0.45, P = .04, and 1.67 ± 0.35 to 2.14 ± 0.21, P = .05). Experiment 4: baseline percentage contrast defect length was similar in both groups but with insulin decreased with time and was significantly lower than in controls at 60 minutes (2.8 ± 5.7 vs 13.7 ± 10.6, P = .02). CONCLUSIONS: Presence of T2DM, insulin infusion duration, and dose are important determinants of the MBFR response to HE. When given immediately following revascularization for STEMI, insulin-dextrose reduces perfusion defect size at one hour. Hyperinsulinemic euglycemia may improve MBF following ischemia, but further studies are needed to clarify this.

The Effect of Different Exercise Modes on Domain-Specific Cognitive Function in Patients Suffering from Parkinson's Disease: A Systematic Review of Randomized Controlled Trials.

BACKGROUND: Supervised exercise training alleviates motor symptoms in people with Parkinson's disease (PD). However, the efficacy of exercise to improve nonmotor symptoms such as cognitive function is less well known. OBJECTIVE: To systematically review evidence on the efficacy of different exercise modes (coordination exercise, resistance exercise, aerobic exercise) on domain-specific cognitive function in patients with PD. METHODS: Parallel-group randomized controlled trials published before March 2018 were included. Primary outcome measures included global cognitive function and its subdomains, and the Unified Parkinson's Disease Rating Scale was included as a secondary outcome. Methodological quality was assessed using the Physiotherapy Evidence Database scale. RESULTS: The literature search yielded 2,000 articles, of which 11 met inclusion criteria. 508 patients (mean age 68±4 years) were included with a disease severity from 1 to 4 on the Hoehn & Yahr stage scale. Overall study quality was modest (mean 6±2, range 3-8/10). In 5 trials a significant between-group effect size (ES) was identified for tests of specific cognitive domains, including a positive effect of aerobic exercise on memory (ES = 2.42) and executive function (ES = 1.54), and of combined resistance and coordination exercise on global cognitive function (ES = 1.54). Two trials found a significant ES for coordination exercise (ES = 0.84-1.88), which led to improved executive function compared with that of non-exercising control subjects. CONCLUSION: All modes of exercise are associated with improved cognitive function in individuals with PD. Aerobic exercise tended to best improve memory; however, a clear effect of exercise mode was not identified.

Leg blood flow and skeletal muscle microvascular perfusion responses to submaximal exercise in peripheral arterial disease.

Peripheral arterial disease (PAD) is characterized by stenosis and occlusion of the lower limb arteries. Although leg blood flow is limited in PAD, it remains unclear whether skeletal muscle microvascular perfusion is affected. We compared whole leg blood flow and calf muscle microvascular perfusion after cuff occlusion and submaximal leg exercise between patients with PAD ( n = 12, 69 ± 9 yr) and healthy age-matched control participants ( n = 12, 68 ± 7 yr). Microvascular blood flow (microvascular volume × flow velocity) of the medial gastrocnemius muscle was measured before and immediately after the following: 1) 5 min of thigh-cuff occlusion, and 2) a 5-min bout of intermittent isometric plantar-flexion exercise (400 N) using real-time contrast-enhanced ultrasound. Whole leg blood flow was measured after thigh-cuff occlusion and during submaximal plantar-flexion exercise using strain-gauge plethysmography. Postocclusion whole leg blood flow and calf muscle microvascular perfusion were lower in patients with PAD than control participants, and these parameters were strongly correlated ( r = 0.84, P < 0.01). During submaximal exercise, total whole leg blood flow and vascular conductance were not different between groups. There were also no group differences in postexercise calf muscle microvascular perfusion, although microvascular blood volume was higher in patients with PAD than control participants (12.41 ± 6.98 vs. 6.34 ± 4.98 arbitrary units, P = 0.03). This study demonstrates that the impaired muscle perfusion of patients with PAD during postocclusion hyperemia is strongly correlated with disease severity and is likely mainly determined by the limited conduit artery flow. In response to submaximal leg exercise, microvascular flow volume was elevated in patients with PAD, which may reflect a compensatory mechanism to maintain muscle perfusion and oxygen delivery during recovery from exercise. NEW & NOTEWORTHY This study suggests that peripheral arterial disease (PAD) has different effects on the microvascular perfusion responses to cuff occlusion and submaximal leg exercise. Patients with PAD have impaired microvascular perfusion after cuff occlusion, similar to that previously reported after maximal exercise. In response to submaximal exercise, however, the microvascular flow volume response was elevated in patients with PAD compared with control. This finding may reflect a compensatory mechanism to maintain perfusion and oxygen delivery during recovery from exercise.

Association of time spent in physical activities and sedentary behaviors with carotid-femoral pulse wave velocity: A systematic review and meta-analysis.

BACKGROUND AND AIMS: Increased arterial stiffness is linked to increased risk of cardiovascular disease and mortality. Studies have reported conflicting results regarding the relationship between arterial stiffness and time spent in sedentary behavior (SB) and physical activity (PA). The objective of this systematic review and meta-analysis was to assess the relationship between objectively measured light PA (LPA), moderate to vigorous PA (MVPA), and SB with the gold standard measurement of arterial stiffness, carotid-femoral pulse wave velocity (cfPWV). METHODS: PubMed, Scopus, and Web of Science were searched for relevant studies published until November 2016. Studies reporting the correlation of objectively measured PA and SB with cfPWV in human adults >18 years old were included in this analysis. Correlation coefficients (CCs) were converted to Z scores via Fisher's z values for the analysis of summary effects, using a random-effects model. RESULTS: Twelve studies were included in the systematic review. The meta-analysis showed a negative correlation between cfPWV and LPA (CC -0.16; 95% CI: -0.29 to -0.03; p=0.02) and MVPA (CC -0.16; 95% CI: -0.26 to -0.06; p<0.01), and a positive relationship between cfPWV and SB (CC 0.23; 95% CI: 0.12 to 0.35; p<0.01). CONCLUSIONS: Time spent in light and moderate physical activities is associated with lower arterial stiffness, while time spent in SB is related to higher arterial stiffness. It suggests that PA at any intensity is favorable for arterial stiffness, whereas SB leads to increased arterial stiffness. Considering that cfPWV has an independent prognostic value, these associations may have important clinical implications.

Combined Lower Limb Revascularisation and Supervised Exercise Training for Patients with Peripheral Arterial Disease: A Systematic Review of Randomised Controlled Trials.

BACKGROUND: Both revascularisation and supervised exercise training improve functional outcomes and quality of life in patients with peripheral arterial disease (PAD). However, the value of combined therapy, where exercise therapy is delivered as an adjunct to revascularisation, is less clear. OBJECTIVE: To systematically review evidence on the efficacy of lower limb revascularisation combined with supervised exercise training in patients with PAD. METHODS: Parallel-group randomised controlled trials indexed in the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, Scopus, CINAHL, SPORTDiscus and Web of Science were searched (up to Jan 2016). Outcome measures were pain-free and maximum walking distances, ankle-brachial index (ABI), leg blood flow and quality of life. Methodological quality was assessed using the Physiotherapy Evidence Database (PEDro) scale. RESULT: Eight trials were included that enrolled a total of 726 patients (mean age 66 ± 3 years, ABI 0.66 ± 0.05). Combined therapy led to greater improvements in pain-free (mean difference [MD] range 38-408 m) and maximal walking distances (MD range 82-321 m) compared with revascularisation or supervised training alone. Combined therapy had no added effect on resting ABI over revascularisation (MD range -0.05 to 0.13), and had a significantly greater effect than supervised exercise training alone (MD range 0.13-0.31). Limited evidence (one to three trials) also suggested that combined therapy led to greater improvements in leg blood flow and physical domains of quality of life than supervised exercise training alone, and that improvements in leg blood flow, as well as the physical and mental domains of quality of life were not different to that achieved with revascularisation alone. CONCLUSION: Current evidence suggests that PAD patients treated with combined therapy achieve greater functional benefits than those treated with revascularisation or supervised exercise training alone. Limited evidence also suggests that the effect of combined therapy on leg haemodynamics and quality of life may be superior to supervised exercise training alone, and similar to revascularisation alone.

Influence of endurance and resistance exercise order on the postexercise hemodynamic responses in hypertensive women.

The study aims to evaluate the effects of the order of endurance and resistance exercises on postexercise blood pressure (BP) and hemodynamics in hypertensive women. Nineteen hypertensive women underwent 3 sessions: control (50 minutes rest), endurance (50-60% of heart rate reserve) followed by resistance exercise (50% of 1 repetition maximum) (E + R), and resistance followed by endurance exercise (R + E). Before and 30 minutes after each session, BP, peripheral vascular resistance, cardiac output, stroke volume, and heart rate were measured. Postexercise increases in systolic (E + R: +1 ± 3 mm Hg and R + E: +3 ± 3 mm Hg), diastolic (E + R: +3 ± 1 mm Hg and R + E: +3 ± 2 mm Hg), and mean BP (E + R: +3 ± 1 mm Hg and R + E: +3 ± 2 mm Hg) were significantly lower after the exercise sessions compared with the control session (p ≤ 0.05). The exercise sessions abolished the increases in peripheral vascular resistance (E + R: +0.00 ± 0.04 mm Hg·min·L and R + E: +0.05 ± 0.05 mm Hg·min·L) and the decreases in cardiac output (E + R: +0.04 ± 0.28 L·min and R + E: -0.26 ± 0.28 L·min) observed after the control session (p ≤ 0.05). After the exercise sessions, stroke volume decreased (E + R: -14 ± 3 ml and R + E: -9 ± 4 ml) and heart rate increased (E + R: +5 ± 1 b·min and R + E: +4 ± 1 b·min) in comparison with the control session (p ≤ 0.05). For all the variables, there were no significant differences between the exercise sessions. Regardless of the order of endurance and resistance exercises, combined exercise sessions abolished increases in BP observed in a control condition due to a reduction in peripheral vascular resistance and increases in cardiac output. Thus, combined exercises should be prescribed to individuals with hypertension to control their BP, regardless of the order they are accomplished.

Clinical predictors of ventilatory threshold achievement in patients with claudication.

PURPOSE: Ventilatory threshold (VT) is considered a clinically important marker of cardiovascular function in several populations, including patients with claudication, because it is related to walking capacity and hemodynamics. The purpose of this study was to identify clinical predictors for VT achievement in patients with intermittent claudication. METHODS: One hundred and seventy-seven (n = 177) patients with intermittent claudication performed a progressive graded cardiopulmonary treadmill test until maximal claudication pain. Oxygen uptake (V˙O2) was continuously measured during the test, and afterwards, VT was visually detected. Clinical characteristics, demographic data, comorbid conditions, and cardiovascular risk factors were obtained. Patients who achieved and did not achieve VT were compared, as well as the workload that VT occurred in the former group. RESULTS: VT was achieved in 134 patients (76%), and the mean V˙O2 at VT for these patients was 10.8 ± 2.4 mL·kg(-1)·min(-1). Patients who did not achieve VT presented lower ankle brachial index (ABI), claudication onset time, peak walking time, and V˙O2peak, and the proportion of women was higher compared with patients who achieved VT (P < 0.05). Multiple linear regression analysis identified that sex (b = 0.25, P = 0.002), body mass index (b = -0.18, P = 0.025), peak walking time (b = 0.17, P = 0.044), and ABI (b = 0.23, P = 0.006) were predictors of V˙O2 at VT. CONCLUSIONS: Forty-three patients (24%) with intermittent claudication did not achieve VT, and these patients were mostly women and those with greater severity of disease. Moreover, in those who reached VT, the predictors of poor VT were female sex, high body mass index, low peak walking time, and low ABI.

Efeito do treinamento de força na flexibilidade: uma revisão sistemática / Effect of strength training on flexibility: a systematic review

O objetivo do presente estudo foi determinar o efeito do treinamento de força na flexibilidade de indivíduos adultos jovens e idosos. Foi realizada uma revisão sistemática de artigos científicos originais indexados nas bases de dados eletrônicas MEDLINE, LILACS, SciELO, Web of Knowlege e Scopus, até o ano de 2012. Foram selecionados estudos que incluíram termos no título e descritores relacionados com a flexibilidade e o treinamento de força. Dezesseis artigos foram incluídos na revisão. Dos cinco estudos com a população idosa, todos reportaram aumento da flexibilidade após o treinamento de força, independente do protocolo e do método/instrumento utilizado. Em indivíduos adultos jovens, sete estudos observaram aumento na flexibilidade com o treinamento de força em pelo menos uma articulação, ao passo que quatro estudos não observaram qualquer alteração. Não foi possível identificar características na amostra ou nos protocolos de treinamento que pudessem diferenciar os estudos que observaram efeitos significantes e não significantes do treinamento de força na flexibilidade. Entretanto, todos os estudos que utilizaram o goniômetro1-4 ou o flexímetro reportaram aumento da flexibilidade em pelo menos uma articulação. Em conclusão, o treinamento de força aumenta a flexibilidade de indivíduos idosos, ao passo que em adultos jovens, aumentos da flexibilidade com o treinamento de força são controversos.

The aim of this study was to identify factors that influence the effects of strength training on young adults and elderly flexibility. Systematic review of original scientific articles indexed in the electronic databases MEDLINE, LILACS, SciELO, Web of Knowledge and Scopus, by the year 2012, was performed. There were selected studies that included terms in the title and keywords related to flexibility and strength training. Sixteen articles were included in the review. Of the five studies with the elderly population, all reported increased flexibility after strength training, regardless of the protocol and the method / instrument used. In young adults, seven studies observed increases in flexibility following strength training in at least one articulation, while four studies have not found any alteration. It was not possible to identify characteristics in the sample or in the training protocols that could differentiate the studies that observed significant and no significant effects of training on flexibility. However, all studies using goniometer or fleximeter reported increased flexibility in at least one articulation. In conclusion, strength training increases flexibility of elderly individuals, whereas in young adults, increases in flexibility due to strength training are controversial.

Segurança, reprodutibilidade, fatores intervenientes e aplicabilidade de testes de 1-RM / Safety, reliability, intervenient factors and applicability of 1-RM tests

Um dos métodos mais utilizados para mensuração da força muscular é o teste de uma repetição máxima (1-RM), tendo em vista a sua versatilidade para aplicação em diferentes exercícios, a especificidade do movimento e o baixo custo operacional. Neste trabalho discutimos as evidências disponíveis a respeito da segurança, da reprodutibilidade, dos fatores intervenientes e da aplicabilidade prática do teste de 1-RM. Com base nas informações disponíveis até o presente momento, o teste de 1-RM parece ser um método seguro do ponto de vista ortopédico e cardiovascular e a sua reprodutibilidade depende, fundamentalmente, da realização de procedimentos de testagem adequados para a estabilização da carga, assim como do controle dos fatores intervenientes os quais podem influenciar no desempenho do teste. Embora a aplicabilidade para o diagnóstico e acompanhamento da força muscular seja ampla, a utilização de testes de 1-RM para a prescrição de treinamento com pesos ainda é bastante discutível.

One of the most used methods for measuring muscular strength is the one repetition maximum test (1-RM), since its versatility for use in different exercises, its specificity of movement and low operating cost. Despite the advantages, some questions remain unclear. In this study we discuss about the available evidences regarding safety, reproducibility, intervenient factors and the practical applicability of the 1-RM test. The available evidence suggests that the 1-RM test is cardiovascular and orthopedic safely and Its reliability depends on the appropriate test procedures used for load stabilization as well as the control of intervenient factors that may influence the test performance. Although the applicability for the diagnosis and monitoring of muscular strength is large, the use of the 1-RM tests for the prescription of weight training is highly debatable.

Validade das equações preditivas de uma repetição máxima varia de acordo com o exercício realizado em adultos jovens treinados / Vadidity of one repetition maximum predictive equations vary according to the exercise performed in trained young adults

O objetivo deste estudo foi verificar a validade de equações preditivas para a estimativa de uma repetição máxima (RM) em diferentes exercícios, em adultos jovens com experiência em treinamento com pesos (TP). Dezesseis homens (21,4±4,0 anos), praticantes de TP, realizaram testes de 1-RM e de 8-12 RM nos exercícios leg press 45°, supino reto, extensão de joelho unilateral, remada central, flexão de joelhos e elevação frontal. Seis equações preditivas foram utilizadas para a predição dos valores de 1-RM: Adams; Baechle & Groves; Brzycki; Epley; Lander; O?Connor et al. Todas as equações analisadas superestimaram os valores de 1-RM no leg press 45º (6 a 15%, p<0,05). No supino reto e elevação frontal, as equações de O?Connor et al. e Adams foram as que produziram as melhores estimativas de 1-RM. Embora todas as equações analisadas tenham proporcionado estimativas válidas para o exercício extensão de joelho unilateral, a equação de O?Connor et al. apresentou melhor desempenho entre elas. No exercício remada central foram consideradas válidas as equações de Brzycki, Epley e Lander, com as duas primeiras apresentando menor erro de estimativa e melhor concordância. Finalmente, no exercício flexão de joelhos, a equação de Baechle & Groves foi a que apresentou melhor desempenho, apesar das equações de Brzycki, Epley e Lander também serem válidas para a estimativa de 1-RM. Os resultados sugerem que a validade das equações preditivas de 1-RM é exercício-dependente e há necessidade de desenvolvimento de equações preditivas para estimativa de valores de 1-RM para o leg press 45º.

The aim of this study was to verify the validity of predictive equations for the estimation of one repetition maximum (RM) in different exercises, in young adults with weight training (WT) experience. Sixteen men (21.4±4.0 years), WT practitioners, conducted 1-RM and 8-12 RM tests for leg press45°, bench press, unilateral knee extension, central rowing, knee flexion and frontal raises. Six predictive equations were used for prediction of 1-RM values: Adams; Baechle & Groves; Brzycki; Epley; Lander; O?Connor et al. All the analyzed equations overestimated the leg press 45º 1-RM values (6 to 15%, p <0.05). In the bench press and front raises, O?Connor et al. and Adams equations were, respectively, the ones that produced the best estimation of 1-RM. Although all analyzed equations have provided valid estimation for the unilateral knee extension exercise, the O?Connor et al. equation showed the best performance among them. In the central rowing exercise, the Brzycki, Epley and Lander equations were considered valid, with the first two featuring lower estimation error and better agreement. Finally, in the knee flexion exercise, Baechle & Groves equation showed the best performance, although the Brzycki, Epley and Lander equations have also been valid for 1-RM estimation. The results suggest that the validity of 1-RM predictive equations is exercise-dependent and it is required the development of predictive equations for estimating the 1-RM values for the leg press 45º.

Isokinetic strength and endurance in proximal and distal muscles in patients with peripheral artery disease.

BACKGROUND: The objective of this study was to analyze the muscle strength and endurance of the proximal and distal lower-extremity muscles in peripheral artery disease (PAD) patients. METHODS: Twenty patients with bilateral PAD with symptoms of intermittent claudication and nine control subjects without PAD were included in the study, comprising 40 and 18 legs, respectively. All subjects performed an isokinetic muscle test to evaluate the muscle strength and endurance of the proximal (knee extension and knee flexion movements) and distal (plantar flexion and dorsiflexion movements) muscle groups in the lower extremity. RESULTS: Compared with the control group, the PAD group presented lower muscle strength in knee flexion (-14.0%), dorsiflexion (-26.0%), and plantar flexion (-21.2%) movements (P < 0.05) but similar strength in knee extension movements (P > 0.05). The PAD patients presented a 13.5% lower knee flexion/extension strength ratio compared with the control subjects (P < 0.05), as well as lower muscle endurance in dorsiflexion (-28.1%) and plantar flexion (-17.0%) movements (P < 0.05). The muscle endurance in knee flexion and knee extension movements was similar between PAD patients and the control subjects (P > 0.05). CONCLUSION: PAD patients present lower proximal and distal muscle strength and lower distal muscle endurance than control patients. Therefore, interventions to improve muscle strength and endurance should be prescribed for PAD patients.

Reprodutibilidade da medida da pressão arterial auscultatória durante o exercício de força / Reproducibility of auscultatory blood pressure measurement during resistance exercise

O método auscultatório tem sido sugerido como opção viável para a medida da pressão arterial (PA) durante o exercício de força. Todavia, os indicadores de reprodutibilidade deste método durante o exercício de força ainda não foram estabelecidos. O objetivo do estudo foi analisar a reprodutibilidade intra e interavaliadores da medida da PA auscultatória obtida durante o exercício de força. Quatorze sujeitos (24±5 anos; 22,0±2,4 kg/m²; PA sistólica: 116±7 mmHg e PA diastólica: 75±4 mmHg) realizaram três séries de 15 repetições, com 50% de 1-repetição máxima no exercício extensão de joelhos em dois momentos distintos (M1 e M2). Antes e durante os séries, a PA sistólica e diastólica foram medidas em ambos os braços simultaneamente por dois avaliadores. O coeficiente de correlação intraclasse (ICC) intra-avaliador da PA sistólica foi de 0,75 (0,57-0,86) e 0,76 (0,59-0,87) para os avaliadores 1 e 2, respectivamente. Além disso, os valores da PA sistólica foram similares entre o M1 e M2, tanto para o avaliador 1 (144±9 vs 146±18, p=0,08), como para o avaliador 2 (152±9 vs. 153±12, p=0,32). O ICC interavaliadores da PA sistólica foi 0,68 (0,46 - 0,82) e o da PA diastólica foi de 0,21 (0,11-0,50). Pode-se concluir que a medida auscultatória da PA sistólica durante o exercício de força apresenta reprodutibilidade intra e interavaliadores, variando de 0,68 a 0,76, ao passo que a medida PA diastólica, durante o exercício de força, apresenta baixos níveis de reprodutibilidade.

The auscultatory method has been suggested as a viable option for blood pressure (BP) measurement during resistance exercise. However, indicators of reproducibility of this method during resistance exercise have not been established. This study aimed to analyze intra- and inter-examiner reproducibility of auscultatory BP measurements obtained during resistance exercise. Fourteen subjects (24 ± 5 years; 22.0 ± 2.4 kg/m²; systolic BP, 116 ± 7 mmHg; diastolic BP, 75 ± 4 mmHg) performed three sets of 15 repetitions of the knee extension exercise at 50% of their 1-repetition maximum at two different time points (T1 and T2). Before and during exercise, systolic and diastolic BP were measured simultaneously in both arms by two examiners. The intra-examiner intraclass correlation coefficient (ICC) for systolic BP was 0.75 (0.57-0.86) and 0.76 (0.59-0.87) for examiners 1 and 2, respectively. In addition, systolic BP values were similar at T1 and T2 both for examiner 1 (144 ± 9 vs. 146 ± 18, p = 0.08) and examiner 2 (152 ± 9 vs. 153 ± 12, p = 0.32). Inter-examiner ICC was 0.68 (0.46-0.82) for systolic BP and 0.21 (0.11-0.50) for diastolic BP. It can be concluded that auscultatory systolic BP measurement during resistance exercise shows intra- and inter-examiner reproducibility ranging from 0.68 to 0.76, whereas diastolic BP measurement during resistance exercise shows low reproducibility.

Post exercise cardiovascular effects of different resistance exercise protocols for trunk and upper limbs / Efeito de diferentes protocolos de exercício de força para o tronco e membros superiores nas respostas cardiovasculares pós-exercício

Objective: to analyze the post exercise cardiovascular effects of different resistance exercise protocols for trunk and upper limbs. Methods: Fifteen males (22.3 ± 0.9 years) underwent three experimental sessions randomly: control session (C), resistance exercise session at 50% of one repetition maximum (1-RM) (E50%), and resistance exercise session at 70% of 1-RM (E70%). Three sets of 12, 9 and 6 repetitions were performed for each exercise. Blood pressure (BP), heart rate (HR) and rate pressure product (RPP) were measured before and during 90 minutes after each session. Results: Systolic BP decreased (P<.05) and diastolic BP increased (P<.05) similarly after C, E50% and E70%. However, HR and RPP decreased after C (P<.01), maintained after E50%, and increased after E70% (P<.01). Conclusions: The resistance exercise intensity did not influence post-exercise BP responses, however, cardiac overload was greater after E70%.

Objetivo: Analisar o efeito de diferentes protocolos de exercício de força para o tronco e membros superiores nas respostas cardiovasculares pós-exercício. Métodos: Quinze homens (22.3 ± 0.9 anos) realizaram três sessões de exercício de força para tronco e membros superiores aleatoriamente: sessão controle (C), sessão de exercício de força a 50% de 1-repetição máxima (1-RM) (E50%) e sessão de exercício de força a 70% de 1-RM (E70%). Foram realizadas três séries de 12, 9 e 6 repetições, respectivamente, para cada exercício. A pressão arterial (PA), a frequência cardíaca (FC) e o duplo produto (DP) foram medidos antes e durante 90 minutos após cada sessão. Resultados: a PA sistólica diminuiu (P<.05) e a PA diastólica aumentou (P<.05) de forma semelhante após C, E50% e E70%. Entretanto, a FC e o DP diminuíram após C (P<.01), mantiveram-se após E50% e aumentaram após E70% (P<.01). Conclusão: A intensidade do exercício de força não influenciou a resposta da PA pós-exercício, contudo, a sobrecarga cardiovascular foi maior após E70%.

Efeito agudo da intensidade do exercício de força na modulação autonômica cardíaca pós-exercício / Acute effect of resistance exercise intensity in cardiac autonomic modulation after exercise / Efecto agudo de intensidad del ejercicio de fuerza en la modulación autónoma del corazón post-ejercicio

FUNDAMENTO: O balanço simpatovagal cardíaco se altera após o exercício de força. Contudo, o impacto das características do treinamento de força nessa resposta ainda não está claro. OBJETIVO: Analisar o efeito agudo da intensidade do exercício de força para tronco e membros superiores na modulação autonômica cardíaca pós-exercício. MÉTODOS: Quinze homens jovens realizaram três sessões experimentais em ordem aleatória: controle (C), exercício de força com 50 por cento de 1-RM (E50 por cento) e exercício de força com 70 por cento de 1-RM (E70 por cento). As sessões incluíram 05 exercícios para tronco e membro superior, realizados em três séries de 12, 9 e 6 repetições, respectivamente. Antes e aos 20 e 50 minutos após as intervenções, a frequência cardíaca foi medida para posterior análise espectral da sua variabilidade. RESULTADOS: Em comparação aos valores anteriores à intervenção, o intervalo RR e a banda de alta frequência (AF) aumentaram (maiores alterações: + 112 ± 83 ms; +10 ± 11 un, respectivamente, p < 0,01), enquanto que a banda de baixa frequência (BF) e a razão BF/AF diminuíram (maiores alterações: -10 ± 11 un; -2 ± 2, respectivamente, p < 0,01) após a sessão C. Nenhuma dessas variáveis se alterou significantemente após a sessão E50 por cento (p > 0,05). Em comparação aos valores pré-exercício, o intervalo RR e a banda AF diminuíram (maiores alterações: -69 ± 105 ms; -13 ± 14 un, respectivamente, p < 0,01), enquanto que a banda BF e a razão BF/AF aumentaram (maiores alterações: -13 ± 14 un, +13 ± 14 un e +3 ± 3 un, respectivamente, p < 0,01) após a E70 por cento. CONCLUSÃO: A maior intensidade de exercício de força para tronco e membros superiores promoveu, agudamente, maior aumento do balanço simpatovagal cardíaco pós-exercício.

BACKGROUND: Cardiac sympathovagal balance is altered after resistance exercise. However, the impact of the characteristics of resistance training in this response remains unclear. OBJECTIVE: Analyze the acute effect of resistance exercise intensity for trunk and upper limbs in cardiac autonomic modulation after exercise. METHODS: Fifteen young men performed three experimental sessions in random order: control (C), resistance exercise with 50 percent of 1-RM (E50 percent) and resistance exercise with 70 percent of 1-RM (E70 percent). The sessions included 05 exercises for the trunk and upper limbs performed in three sets of 12, 9 and 6 repetitions, respectively. Before and at 20 and 50 minutes after the interventions, the heart rate was measured for spectral analysis of variability. RESULTS: In comparison to the values before the intervention, the RR interval and the band of high frequency (HF) increased (major changes: + 112 ± 83 ms; +10 ± 11 un, respectively, p < 0.01), while the low frequency band (LF) and LF/HF ratio decreased (major changes: -10 ± 11 pc; -2 ± 2, respectively, p < 0.01) after the session C. None of these variables changed significantly after the E50 percent session (p > 0.05). Compared to pre-exercise values, the RR interval and the HF band decreased (major changes: -69 ± 105 ms; -13 ± 14 un, respectively, p <0.01), while the LF band and the LF/HF ratio increased (major changes: -13 ± 14 un, 13 ± 3 14 ± 3 and un, respectively, p <0.01) after E70 percent. CONCLUSION: The higher intensity of resistance exercise for trunk and upper limbs promoted, in an acute manner, greater increase in cardiac sympathovagal balance after exercise.

FUNDAMENTO: El balance simpatovogal cardíaco se altera después del ejercicio de fuerza. Sin embargo, el impacto de las características del entrenamiento de fuerza en esta respuesta no está claro. OBJETIVO: Analizar el efecto agudo de intensidad del ejercicio de fuerza para el tronco y miembros en la modulación autonómica del corazón post-ejercicio. MÉTODOS: Quince hombres jóvenes realizaron tres sesiones experimentales en orden aleatorio: control (C), ejercicio de fuerza con el 50 por ciento de 1-RM (E50 por ciento) y ejercicio de fuerza con el 70 por ciento de 1-RM (E70 por ciento). Las sesiones incluyeron 05 ejercicios para tronco y miembro superior, realizados en tres series de 12, 9 y 6 repeticiones, respectivamente. Antes y a los 20 y 50 minutos después de las intervenciones, la frecuencia cardiaca se midió para un análisis espectral posterior de su variabilidad. RESULTADOS: En comparación con los valores anteriores de la intervención, el intervalo RR y la banda de alta frecuencia (AF) se incrementó (cambios importantes: + 112 ± 83 ms; +10 ± 11 un, respectivamente, p < 0,01), mientras que la banda de baja frecuencia (BF) y la razón BF/AF disminuyeron (cambios importantes: -10 ± 11 un; -2 ± 2, respectivamente, p < 0,01) tras la sesión C. Ninguna de estas variables se alteró significantemente tras la sesión E50 por ciento (p > 0,05). En comparación a los valores pre ejercicio, el intervalo RR y la banda AF disminuyeron (cambios importantes: -69 ± 105 ms; -13 ± 14 un, respectivamente, p < 0,01), mientras que la banda BF y la razón BF/AF aumentaron (cambios importantes: -13 ± 14 un, +13 ± 14 un y +3 ± 3 un, respectivamente, p < 0,01) tras la E70 por ciento. CONCLUSIÓN: La mayor intensidad de ejercicio de fuerza para el tronco y miembros superiores produjo de modo agudo, un mayor incremento simpatovagal cardíaco post-ejercicio.

Relação entre aptidão física e os indicadores de qualidade de vida de indivíduos com claudicação intermitente / Correlation between physical fitness and indicators of quality of life of individuals with intermittent claudication

O objetivo deste estudo foi verificar a relação entre a aptidão física e os indicadores de qualidade de vida de indivíduos com claudicação intermitente (CI). Participaram do estudo 42 indivíduos (65,2 ± 8,3 anos) com CI, de ambos os gêneros. Para a avaliação da aptidão física, foram realizados teste de esforço em esteira, para obtenção da distância de claudicação (DC) e da distância total de marcha (DTM) e o teste de uma repetição máxima no exercício extensão de joelho. Os indicadores de qualidade de vida foram avaliados por meio do Medical Outcome Study Questionnaire Short Form 36, composto por oito domínios: capacidade funcional (CF), aspectos físicos (AF), dor, estado geral de saúde, vitalidade (VI), aspectos sociais (AS), aspectos emocionais (AE) e saúde mental. Para a análise estatística foi utilizado o coeficiente de correlação de Pearson, com p < 0,05. Foi observada correlação significante entre o domínio da CF com a DC e a DTM (r = 0,60, p < 0,01 e r = 0,49, p < 0,01, respectivamente), o domínio da AF com a DTM (r = 0,46, p < 0,01), o domínio da VI e dos AS com a DC (r = 0,34, p = 0,03 e r = 0,33, p = 0,04, respectivamente) e o domínio da AE com a DC e a DTM (r = 0,43, p = 0,01 e r = 0,44, p = 0,01, respectivamente). Como conclusão, os resultados deste estudo sugerem que os indicadores da qualidade de vida nos domínios da saúde física e da saúde emocional são relacionados com a capacidade de caminhada de indivíduos com CI.

The aim of this study was to investigate the relationship between physical fitness and the indicators of quality of life in individuals with intermittent claudication (IC). Forty-two subjects (65.2 ± 8.3 years) with IC of both genders participated in the study. Exercise treadmill test, to assess claudication distance (CD) and total walking distance (TWD), and one repetition maximum knee extension test were used to evaluate physical fitness. The quality of life indicators were obtained from the Medical Outcome Study Questionnaire Short Form, which is composed of eight domains: physical functioning (PF), physical aspects (PA), pain, general health, vitality (VI), social functioning (SF), emotional aspects (EA) and mental health. For statistical analysis Pearson correlation coefficient was used, with p < 0.05. There was a significant correlation between PF and CD and TWD (r = 0.60, p < 0.01 and r = 0.49; p < 0.01, respectively), between RP and TWD (r = 0.46, p < 0.01), between VI and SF and CD (r = 0.34, p = 0.03 e r = 0.33, p = 0.04; respectively), and between EA and CD and TWD (r = 0.43, p = 0.01 and r = 0.44, p = 0.01; respectively). In conclusion, the results of this study suggest that indicators of quality of life, both related to physical health and emotional health, are correlated with the walking capacity in patients with IC.