The purpose of this study was to analyze systolic blood pressure (SBP), diastolic blood pressure (DBP) and the heart rate (HR) before, during and after training at moderate intensity (MI, 50%-1RM) and at low intensity with blood flow restriction (LIBFR). In a randomized controlled trial study, 14 subjects (average age 45±9,9 years) performed one of the exercise protocols during two separate visits to the laboratory. SBP, DBP and HR measurements were collected prior to the start of the set and 15, 30, 45 and 60 minutes after knee extension exercises. Repeated measures of analysis of variance (ANOVA) were used to identify significant variables (2 × 5; group × time). The results demonstrated a significant reduction in SBP in the LIBFR group. These results provide evidence that strength training performed acutely alters hemodynamic variables. However, training with blood flow restriction is more efficient in reducing blood pressure in hypertensive individuals than training with moderate intensity.

Water-based exercise and low-intensity exercise in combination with blood flow restriction (BFR) are two methods that have independently been shown to improve muscle strength in those of advancing age. The objective of this study was to assess the long-term effect of water-based exercise in combination with BFR on maximum dynamic strength and functional capacity in post-menopausal women. Twenty-eight women underwent an 8-week water-based exercise program. The participants were randomly allocated to one of the three groups: (a) water exercise only, (b) water exercise + BFR, or (c) a non-exercise control group. Functional capacity (chair stand test, timed up and go test, gait speed, and dynamic balance) and strength testing were tested before and after the 8-week aquatic exercise program. The main findings were as follows: (1) water-based exercise in combination with BFR significantly increased the lower limb maximum strength which was not observed with water-based exercise alone and (2) water-based exercise, regardless of the application of BFR, increased functional performance measured by the timed up and go test over a control group. Although we used a healthy population in the current study, these findings may have important implications for those who may be contraindicated to using traditional resistance exercise. Future research should explore this promising modality in these clinical populations.

The present study aimed to analyse the effects of six weeks of strength training (ST), with and without blood flow restriction (BFR), on torque, muscle activation, and local muscular endurance (LME) of the knee extensors. Thirty-seven healthy young individuals were divided into four groups: high intensity (HI), low intensity with BFR (LI+BFR), high intensity and low intensity + BFR (COMB), and low intensity (LI). Torque, muscle activation and LME were evaluated before the test and at the 2nd, 4th and 6th weeks after exercise. All groups had increased torque, muscle activation and LME (p<0.05) after the intervention, but the effect size and magnitude were greater in the HI, LI+BFR and COMB groups. In conclusion, the groups with BFR (LI+BFR and COMB) produced magnitudes of muscle activation, torque and LME similar to those of the HI group.

Strength training combined with blood flow restriction (BFR) have been used to improve the levels of muscle adaptation. The aim of this paper was to investigate the acute effect of high intensity squats with and without blood flow restriction on muscular fatigue levels. Twelve athletes (aged 25.95 ± 0.84 years) were randomized into two groups: without Blood Flow Restriction (NFR, n = 6) and With Blood Flow Restriction (WFR, n = 6) that performed a series of free weight squats with 80% 1-RM until concentric failure. The strength of the quadriceps extensors was assessed in a maximum voluntary isometric contraction integrated to signals from the surface electromyogram. The average frequency showed significant reductions in the WFR group for the vastus lateralis and vastus medialis muscles, and intergroup only for the vastus medialis. In conclusion, a set of squats at high intensity with BFR could compromise muscle strength immediately after exercise, however, differences were not significant between groups.

Abstract The production of litterfall is essential for nutrient cycling in terrestrial ecosystems. From November 2009 to October 2011, analyzed the monthly litterfall production in two areas of Caatinga, a type of Seasonally Dry Tropical Forest located in the Cariri Paraibano, in the semiarid region of the Paraíba, Northeastern Brazil. One of the areas, Private Natural Heritage Reserve (RPPN) Fazenda Almas, is legally protected, and the other, Fazenda Moreiras, does not. The aims were to evaluate the effects of precipitation, evapotranspiration and vegetation structure on the temporal and spatial dynamics of litterfall production. Eight sampling points were randomly chosen at each site, and two 1 m2 collectors were installed 50 m apart from each other. The collected material was sorted, dried and weighed. Additionally, the characteristics (density, species richness, height and mean basal area) of the tree-shrub stratum in plots with a 10 m radius surrounding each collector. Total litterfall production was 4,500 kg ha-1 yr-1 for Fazenda Almas and 3,300 kg ha-1 yr-1 for Fazenda Moreiras; these values were within the expected range for Seasonally Dry Tropical Forests. The inter- and intra-annual variation in litterfall production was positively correlated with precipitation and evapotranspiration rates, and four months after the highest precipitation rates, there was a marked decrease in litterfall occurred during the dry season. Furthermore, the contributions of the material fractions were distinct with the leaf fraction representing for more than 60% of the litterfall, and the vegetation structure explained 75% of the variation in litterfall production. Therefore, climatic factors and vegetation structure affect the temporal and spatial dynamics of litterfall production and consequently influence nutrient dynamics in the semiarid region of Brazil.

Changes in hormonal status related to menopause exert negative effects on muscle mass and strength, 1 and may influence physical fitness and functional performance. Resistance training has been shown to maintain or increase strength, 2 muscle mass, 3 and functional performance 4 when using intensities greater than 65% of maximal repetition (1RM). 5 However, high intensities may not be well tolerated by frail elderly or those with joint problems. Thus, resistance training performed with loads between 20 and 50% of 1RM combined with blood flow restriction (LRT-BFR) may be an efficient strategy to promote neuromuscular adaptations similar to high-load resistance training (HRT) without BFR. However, specifically in postmenopausal women, researches on the effect of LRT-BFR on strength, muscle mass, and functional performance are scarce. 6-9 However, in Thiebaud et al. 8 training was performed with elastic bands and in Araújo et al. 7 in an aquatic environment. To use LRT-BFR, it is necessary to increase the safety in the application of the method to avoid potentially negative physiological factors, such as, for example, reduction of nerve conduction velocity, thrombus formation or induction to microvascular occlusion and discomfort 9 , especially in the presence of hypertension, diabetes and endothelial dysfunction, a frequent condition in postmenopausal women. 10 In this study, it was hypothesized that in LRT-BFR, the application of moderate restrictive pressure (RP) during exercise associated with the release of pressure at low levels during rest among series could induce gains similar to those of HRT and would minimize risks and discomfort related to training, favoring adherence. Thus, the aim of this study was to analyze the effects of an LRT-BFR protocol, with reduced RP, on maximum dynamic force, cross-sectional area of the femoral quadriceps and functional performance in postmenopausal women. Additionally, compare the effects of this type of training with HRT on the same variables. Methods A randomized, open label, controlled trial with two parallel arms was performed. With the approval of local Research Ethics Committee (Protocol no. 817.007) the study included twenty-four women (63.1±5.2 years, 66.1±8.5 kg, 153.7±7.4 cm) physically active, 11 functionally independent, with central systolic blood pressure, pulse wave velocity and normal ankle brachial index, 12-14 who did not exercise with weights in the previous six months. Participants who missed three or more consecutive sessions and/or did not attend 75% of training sessions were excluded. Figure 1 depict the flowchart CONSORT diagram. All participants received information about the benefits and

ARTIGO ORIGINAL | ORIGINAL ARTICLE RESUMOO objetivo do presente estudo foi verificar o efeito agudo do exercício predominantemente aeróbico (EA) com restrição de fluxo sanguíneo (RFS) sobre a pressão arterial sistólica (PAS), pressão arterial diastólica (PAD) e frequência cardíaca (FC) em jovens saudáveis. Participaram do estudo 13 universitários normotensos (19.5 ± 1.7anos). Os participantes foram divididos randomicamente em duas sessões experimentais (cross-over): a) exercício aeróbico com a RFS (EARFS); b) exercício aeróbico sem a RFS (EASRFS). As sessões foram realizadas com cinco séries de dois minutos e um minuto de intervalo. A PAS, PAD e FC foram mensurados em repouso, no final dos exercícios e durante os 60 minutos pós-exercício. O EASRFS apresentou efeito hipotensivo no 60º pós-exercício (p= 0.029); o EA com e sem RFS elevou significativamente a PAS e FC imediatamente após o exercício (p< 0.05), e o EARFS apresentou valores de PAD e FC superiores, no momento imediatamente pós-exercício, quando comparado com o EASRFS (p= 0.001; p< 0.001, respectivamente). Conclui-se, que o EARFS parece não maximizar o efeito hipotensivo, ambos as sessões podem elevar a PAS e FC imediatamente pós-exercício com valores significativos maiores na PAD e FC para o EARFS. Palavras-chave: hemodinâmica, oclusão vascular, exercício, efeito hipotensivo. ABSTRACTThe aim of the present study was to verify the acute effect of the aerobic exercise (AE) with blood flow restriction (BFR) upon systolic (SBP), diastolic blood pressure (DBP) and heart rate (HR) in health youngsters. Participated in the present study 13 young normotensive students (19.5 ± 1.7 years old). The sample was randomly divided into two experimental protocols: stationary race with BFR and stationary race without BFR. Subjects performed 5 sets of 2 minutes with 1 minute of rest interval for both protocols. SBP, DBP and HR were measured at rest, in the end of the exercises and during 60 minutes after conditions. The AE without BFR presented hypotensive effect 60 minutes post exercise (p= 0.029); the AE with and without BFR elevated significantly the SBP and HR immediately post exercise (p< 0.05) and the AE with BFR presented higher DBP and HR values immediately post-exercise when compared to AE without BFR (p= 0.001; p< 0.001, respectively). It is concluded that the AE without BFR does not seem to maximize the hypotensive effect, both sessions can increase SBP and HR immediately post-exercise with significant higher values in DBP and HR for AE with BFR.

We compared the effects of aerobic exercise with and without blood flow restriction (BFR) to high‐intensity aerobic exercise on energy expenditure (EE), excess Postexercise oxygen consumption (EPOC), and respiratory exchange ratio (RER) during and after exercise. Twenty‐two recreationally active males randomly completed the following experimental conditions: AE—aerobic exercise without BFR, AE + BFR—aerobic exercise with BFR, HIAE—high‐intensity aerobic exercise, CON—non‐exercise control condition. EE was significantly (p < 0.05) greater during exercise for HIAE compared to all conditions, and for AE + BFR compared to AE and CON during and postexercise exercise. There were no significant (p > 0.05) differences in EPOC between HIAE and AE + BFR at any time point, however, both conditions were significantly (p < 0.05) greater than the AE (d = 1.50 and d = 1.03, respectively) and CON at the first 10 min postexercise. RER during exercise for HIAE was significantly (p < 0.05) greater than AE + BFR at the first 6 min of exercise (p = 0.003, d = 0.88), however, no significant differences were observed from 9 min up to the end of the exercise. HIAE was also significantly (p < 0.05) greater than AE and CON at all time points during exercise, whereas, AE + BFR was significantly (p < 0.05) greater than CON at all time points but not significantly (p < 0.05) different than AE (p < 0.05); although the overall session RER was significantly (p < 0.05) greater during AE + BFR than AE. Altogether, continuous AE + BFR results in greater EE compared to volume matched AE, as well as a similar EPOC compared to HIAE.