The Acute Effect of In Natura Beetroot Juice Intake on Intra-Session Exercise Sequences During Concurrent Training.

The purpose of this study was to analyze the acute effects of in natura beetroot juice intake on intra-session exercise sequences during concurrent training. Following a randomized double-blind placebo-controlled crossover design, 20 well-trained men (21.4 ± 2.9 years; 74.8 ± 6.3 kg; 175.7 ± 5.0 cm) performed two concurrent training sessions with different intra-session exercise sequences: CT1 (aerobic exercise + resistance exercises) and CT2 (resistance exercises + aerobic exercise). The resistance exercises were bench-press, lat-pull down, and shoulder-press (three sets to failure; 2 s cadence for the concentric and eccentric phases; 90 s rest interval between sets and exercises; 75% 1RM), and the aerobic exercise was 4-km running. Each concurrent training session was randomized to placebo, beetroot juice, and control (no substances), totaling six exercise sessions. The rate of perceived exertion (RPE) was reported at the end of each exercise in each session. The beetroot juice significantly increased plasma nitric oxide concentration from 14.5 ± 3.9 mmol/L to 140.2 ± 37.5 mmol/L (P < 0.01) and there was no significant change after placebo intake (13.8 ± 4.2 vs 15.1 ± 5.7 mmol/L). The 4-km running time was significantly less (P < 0.05) after beetroot juice intake in CT1 (17.0 ± 2.1 min) and CT2 (18.5 ± 1.9 min) than placebo (19.1 ± 3.2 and 22.2 ± 2.9 min, respectively) and control (19.4 ± 2.6 and 21.7 ± 3.0 min, respectively). No differences were identified in the total number of repetitions in resistance exercises and RPE. In conclusion, the acute intake of in natura beetroot juice decreased the 4-km running time independently of concurrent training exercise sequences. Our results may assist trainers in order to choose the supplement to increase performance.

Validity and reliability of the 6-min step test in individuals with coronary artery disease.

OBJECTIVE: To assess the validity and reliability of the 6-min step test (6MST) in individuals with coronary artery disease (CAD). METHODS: In a randomized and crossover design, 35 patients with CAD (65.8 ± 9.6 years), referred by a physician of a cardiology ambulatory, performed two 6MSTs and two 6-min walk tests (6MWTs) in order to assess reliability in patients with arterial coronary disease. The order of performance of the tests was established by a draw. RESULTS: 6MST test-retest reliability was excellent (intraclass correlation coefficient = 0.967; 95% CI: 0.766, 0.989; p < .05). There was an increase of 7.9 ± 8.2 steps from the first to the second 6MST, with a technical error of measurement = 8.0; p < .001. The correlations between distance walked in the 6MWT and number of steps in the 6MST in the first and second tests were 0.6 and 0.7 (p < .001), respectively. CONCLUSION: The 6MST is a reliable test to measure functional capacity in individuals with CAD. The test is valid when using 6MWT as the gold standard. There is an 88% chance of a subject classified in a given tertile by the 6MWT being in the same tertile in the 6MST.

Effects of Concurrent Training with Elastic Tubes in Hypertensive Patients: A Blind Controlled Randomized Clinical Trial.

BACKGROUND: Concurrent training (CT) has been recommended to minimize the deleterious effects of aging. However, few studies have investigated whether this type of training reduces blood pressure in the elderly. Therefore, our objective was to evaluate the effects of CT on the hemodynamic, cardiorespiratory, and muscle strength responses in medicated hypertensive patients. METHODS: Twenty-three hypertensives (62.65 ± 6.4 years) of both sexes were allocated to the concurrent training group (CTG) or control group (CG). The CTG performed aerobic training (70-85% of reserve heart rate) combined with resistance training with elastic tubes (2sets × 15 repetitions) for 8 weeks. Resting blood pressure (BP), peak oxygen consumption (VO2peak), and right knee and elbow flexion strength were evaluated. RESULTS: A reduction of 6.37% was observed in BP and increases of 16.68% in VO2peak and 16% in muscle strength for right elbow flexion in the CTG compared to CG (p < .05). Intragroup comparisons showed reduction of 5% for BP, and increases of 6.79% for VO2peak, 24.79% for elbow flexion, and 16.47% for knee flexion in the CTG (p < .05), without significant improvement in the CG. CONCLUSION: CT promoted a reduction in BP, and increased cardiorespiratory fitness and muscular strength of the upper limbs in the hypertensive older adults.

Caffeine and resistance exercise: the effects of two caffeine doses and the influence of individual perception of caffeine.

Although caffeine is a widely used ergogenic resource, some information regarding its effects on resistance exercises is still lacking. The objective of the present study was to verify the acute effect of the ingestion of two different doses of caffeine on performance during a session of resistance exercises and to analyze the perception of the subjects in relation to the intake of caffeine. Following a double-blind, randomised, cross-over, controlled, and non-placebo design, 14 trained and healthy men (24.7 ± 6.8 years; 79.8 ± 9.8 kg; 177.3 ± 8.5 cm) performed a training session in chest-press, shoulder-press, and biceps curl exercises (3 sets until exhaustion; 70% 1RM; 3 min rest interval; 2 s for each concentric and eccentric phase) on three non-consecutive days after ingestion of 3 mg.kg-1 caffeine (CAF3), 6 mg.kg-1 caffeine (CAF6), or no substance (CON). Subjects were informed that one of the caffeine doses would be placebo. The total number of repetitions performed in CON (93.6 ± 22.4) was significantly lower than in CAF3 (108.0 ± 19.9, P = 0.02) and in CAF6 (109.3 ± 19.8, P = 0.03) and there were no differences between caffeine doses. Eight subjects noticed that caffeine was in CAF3 and six in CAF6 and there were no differences in the number of repetitions between sessions in which the subjects perceived and did not perceive caffeine. In conclusion, caffeine doses of 3 or 6 mg.kg-1 similarly increased performance in resistance upper limb exercises, independent of the subject's perception of substance ingestion.

Acute citrulline oral supplementation induces greater post-exercise hypotension response in hypertensive than normotensive individuals / Suplementação oral aguda de citrulina induz maior resposta hipotensiva pós-exercício em indivíduos hipertensos do que normotensos

ABSTRACT Objective To investigate whether acute citrulline supplementation might influence post-exercise hypotension in normotensive and hypertensive individuals. Methods Following a randomized double-blind design, twenty normotensive (28±7 years, 74±17kg, 1.7±0.09m) and 20 hypertensive individuals (55±12 years, 76±15kg, 1.59±0.09m) were randomly assigned to one of the four experimental groups (Normotensive-Placebo; Normotensive-Citrulline; Hypertensive-Placebo; Hypertensive-Citrulline). The placebo groups ingested 6g of corn starch and the citrulline groups ingested 6g of citrulline dissolved in water. The participants performed 40 minutes of walking/running on a treadmill at 60-70% heart rate reserve. Blood pressure was measured immediately after a 60-min exercise session using an oscillometric device and 24-h ambulatory monitoring. Results The post-exercise hypotension was more pronounced in hypertensives and the Hypertensive-Citrulline group showed a consistent systolic blood pressure reduction during the laboratorial phase, which can be seen by looking at the mean of 60 minutes (-15.01mmHg vs -3.14mmHg [P=0.005]; -4.16mmHg [P=0.009]; -6.30mmHg [P=0.033] in comparison with the Normotensive-Placebo, Normotensive-Citrulline, and Hypertensive-Placebo groups, respectively). During ambulatory blood pressure monitoring, the Hypertensive-Citrulline group showed a significant reduction in systolic blood pressure (-21.05mmHg) in the awake period compared with the Normotensive-Citrulline group (-3.17mmHg [P=0.010]). Conclusion Acute citrulline oral supplementation can induce greater post-exercise hypotension response in hypertensive than normotensive individuals.

RESUMO Objetivo Investigar se a suplementação aguda de citrulina pode influenciar a hipotensão pós-exercício em indivíduos normotensos e hipertensos. Métodos Seguindo delineamento duplo-cego randomizado, vinte indivíduos normotensos (28±7 anos, 74±17kg, 1,7±0,09m) e 20 hipertensos (55±12 anos, 76±15kg, 1,59±0,09m) foram randomizados e distribuídos em um dos quatro grupos experimentais (Normotenso-Placebo; Normotenso-Citrulina; Hipertenso-Placebo; Hipertenso--Citrulina). Os grupos placebo ingeriram 6g de amido de milho e os grupos citrulina 6g de citrulina, dissolvidos em água. Os participantes realizaram 40 minutos de caminhada/corrida em esteira a uma intensidade entre 60-70% da frequência cardíaca de reserva. A pressão arterial foi aferida imediatamente após a sessão de exercício por 60 minutos usando um equipamento oscilométrico, e durante 24 horas por monitorização ambulatorial. Resultados A hipotensão pós-exercício foi mais pronunciada nos hipertensos e o grupo Hipertenso-Citrulina mostrou uma redução consistente da pressão arterial sistólica durante a fase laboratorial, o que pode ser visto pela média de 60 minutos (-5,01mmHg vs -3,14mmHg [P=0,005]; -4,16mmHg [P=0,009]; -6,30mmHg [P=0,033] em comparação com o Normotenso-Placebo, Normotenso-Citrulina e Hipertenso-Placebo, respectivamente). Durante a monitorização ambulatorial da pressão arterial, o Hipertenso-Citrulina demonstrou uma redução significativa na pressão arterial sistólica (-21,05mmHg) durante a vigília em comparação com o Normotenso-Citrulina (-3,17mmHg [P=0,010]). Conclusão A suplementação oral aguda de citrulina induz maior resposta hipotensiva pós-exercício em indivíduos hipertensos do que normotensos.

Measurement of physical performance by field tests in programs of cardiac rehabilitation: a systematic review and meta-analysis. / Medida do desempenho físico por testes de campo em programas de reabilitação cardiovascular: revisão sistemática e meta­análise.

INTRODUCTION: The literature concerning the effects of cardiac rehabilitation (CR) on field tests results is inconsistent. PURPOSE: To perform a systematic review with meta-analysis on field tests results after programs of CR. METHODS: Studies published in PubMed and Web of Science databases until May 2016 were analyzed. The standard difference in means correct by bias (Hedges' g) was used as effect size (g) to measure que amount of modifications in performance of field tests after CR period. Potential differences between subgroups were analyzed by Q-test based on ANOVA. RESULTS: Fifteen studies published between 1996 e 2016 were included in the review, 932 patients and age ranged 54,4 - 75,3 years old. Fourteen studies used the six-minutes walking test to evaluate the exercise capacity and one study used the Shuttle Walk Test. The random Hedges's g was 0.617 (P<0.001), representing a drop of 20% in the performance of field test after CR. The meta-regression showed significantly association (P=0.01) to aerobic exercise duration, i.e., for each 1-min increase in aerobic exercise duration, there is a 0.02 increase in effect size for performance in the field test. CONCLUSION: Field tests can detect physical modification after CR, and the large duration of aerobic exercise during CR was associated with a better result.

Avaliação da força muscular extensora do tronco: influência do gênero e do estado de treinamento / Assessment of muscle strength of extension of trunk: influence of gender and state of training

Introdução: O fortalecimento dos músculos extensores do tronco é importante para prevenção da lombalgia. Porém, não está estabelecido se um treinamento não específico para esta região é suficiente. Objetivo: comparar a força dos extensores do tronco de sujeitos sedentários e praticantes de treinamento resistido (TR) que não realizavam exercícios específicos para esta região. Métodos: Foram recrutados 105 indivíduos saudáveis, (61 homens e 44 mulheres), com média de idade entre 18 e 44 anos que foram divididos em grupos de treinados e sedentários. Os experientes em TR treinavam exercícios de agachamento ou de desenvolvimento. Os demais sujeitos não possuíam experiência no TR. Resultados: Foram observadas diferenças na força entre homens treinados e sedentários (p=0,002) e entre os gêneros (p=0,0003), não foi observado diferença entre mulheres treinadas e sedentárias (p≥0,05). Conclusão: o TR não específico é suficiente para aumentar a força da região lombar em homens. Entretanto, não é suficiente no público feminino.

Introduction: Trunk extensor muscles strength is important for low back prevention pain. However, it is not established whether a non-specific training for this region is sufficient. Objective: Compare trunk muscle extensors strength of the sedentary subjects and resistance training practitioners (RT) who did not perform any specific exercises for this region. Methods: It was recruited 105 healthy subjects (61 men and 44 women) with age between 18 and 44 years who were divided into groups trained and sedentary. Experienced in RT trained squat and military press. The remaining subjects had no experience in RT. Results: There were differences in strength between trained and sedentary men (p = 0.002) and gender (p = 0.0003), there was no difference between women trained and sedentary (p≥0.05). Conclusion: RT non specific increase the strength of the lumbar region in men. However, it is not enough in the female public.

Effects of fixed vs. self-suggested rest between sets in upper and lower body exercises performance.

In its last position stand about strength training, the American College of Sports Medicine recommends a rest interval (RI) between sets ranging between 1 and 3 min, varying in accordance with the objective. However, there is no consensus regarding the optimal recovery between sets, and most studies have investigated fixed intervals. Therefore, the aim of this study was to analyse the effects of fixed versus self-suggested RI between sets in lower and upper body exercises performance. Twenty-seven healthy subjects (26 ± 1.5; 75 ± 15 kg; 175 ± 12 cm) were randomly assigned into two groups: G1: lower body exercises and G2: upper body exercises. Squat and leg press 1 repetition maximum (1RM) were tested for the G1 and bench press and biceps curl 1RM for G2. After the 1RM tests, both groups performed three sets to concentric failure with 75% of 1RM in combination with different RIs (2 min or self-suggested) on separate days and the exercises performance was evaluated by the number of repetitions. The results demonstrated no significant differences in the number of repetitions between 2 min and self-suggested RIs that presented similar reductions with the sets progression. It was also shown that the self-suggested RI spent less time recovering than the 2 min RI group on average. This suggests that for individuals with previous experience, the self-suggested RI can be an effective option when using workloads commonly prescribed aiming hypertrophy. Also, the self-suggested RI can reduce the total training session duration, which can be a more time-effective strategy.

Hemodynamic response to resistance exercise with and without blood flow restriction in healthy subjects.

PURPOSE: To compare the hemodynamic response during resistance exercise at high intensity (HI), low intensity (LI) and low intensity with blood flow restriction (LI-BFR) in healthy subjects. METHODS: Twelve men performed three sets of unilateral knee extension exercises at LI-BFR and LI (15 repetitions; 20% of 1RM) and HI (8 repetitions; 80% of 1RM). The blood flow restriction was accomplished using a sphygmomanometer positioned on the thigh and inflated to the point of blood flow interruption (167·9 ± 16·6 mmHg). The hemodynamic variables were obtained by continuous beat-to-beat photoplethysmography. Rating of perceived exertion (RPE) and blood lactate were also measured. RESULTS: The HI session showed higher values (P<0·05) in all sets than the LI and LI-BFR for diastolic blood pressure, heart rate and rate-pressure product. The LI-BFR showed higher values than the LI only in the 3rd set for systolic blood pressure, heart rate and rate-pressure product. Blood lactate was higher in the HI (4·2 ± 0·2 mmol) and LI-BFR (4·1 ± 0·3 mmol) than the LI (3·5 ± 0·3 mmol). Rating of perceived exertion was higher in the LI-BFR (7·9 ± 0·3) than the HI (6·4 ± 0·4) and LI (3·2 ± 0·4). CONCLUSION: The LI-BFR session exhibited similar blood lactate to the HI, a higher rating of perceived response than the HI and LI, and equal or lower hemodynamic responses than the HI.

Direct renin inhibitor therapy and swimming training: hemodynamic and cardiac effects in hypertensive and normotensive rats.

PURPOSE: This study aimed to analyze the hemodynamic and cardiac effects of direct renin inhibitor (DRI) treatment and swimming training in hypertensive rats. METHODS: Seventy-seven rats were divide into eight groups: sedentary normotensive (SN), trained normotensive (TN), sedentary normotensive treated with DRI (SN_DRI), trained normotensive treated with DRI (TN_DRI), sedentary hypertensive (SH), trained hypertensive (TH), sedentary hypertensive treated with DRI (SH_DRI), trained hypertensive treated with DRI (TH_DRI). Swimming training occurred for up to 60 min, five times a week for four weeks. The hypertensive animals were treated with 20 mg c kg(-1) c day(-1) L-NAME for four weeks. Groups treated with DRI received 10 mg c kg(-1) c day(-1) of aliskiren for four weeks. After the treatment period, all the animals underwent femoral artery catheterization surgery for direct measurement of cardiovascular variables. RESULTS: The SH group presented hypertension (136.4 ± 5.0 mmHg) compared to the SN (107.1 ± 1.7 mmHg). The TH group showed lower mean arterial pressure (MAP) than the SH (121.1 ± 1.3 mmHg), but the treatment with DRI did not attenuate hypertension (128.2 ± 4.9 mmHg). The analysis of collagen areas demonstrated that treatment with DRI may attenuate cardiac remodeling in situations of hypertension, in the condition of treatment alone or combined with physical training. CONCLUSION: Both interventions in combination may be more effective at reducing cardiovascular risk in hypertensive subjects.

Testes de Degrau para avaliação da capacidade de exercício em pacientes com doenças cardíacas: revisão de literatura / Step tests for assessing exercise capacity among patients with heart diseases: literature review

Testes de degrau têm sido utilizados em pessoas saudáveis e com doenças pulmonares, porém esse modelo de teste ainda é pouco utilizado em pacientes com doenças cardíacas. Este trabalho tem por objetivo realizar uma revisão de literatura sobre a utilização de testes de degrau para avaliação da capacidade de exercício em pacientes com doenças cardíacas. Foram utilizadas as bases de dados Medline/PubMed, LILACS e SciELO e encontrados 305 artigos, tendo sido 11 incluídos: nove em pacientes com insuficiência cardíaca e dois com doença arterial coronariana. Utilizados os protocolos do Teste de degrau de dois minutos e Teste de dois degraus de Master. O desempenho no degrau foi comparado ao equivalente metabólico, acelerômetro, teste ergométrico em cicloergômetro e teste de exercício cardiopulmonar em esteira em quatro estudos; e ao desempenho em atividades cognitivas, de vida diária, qualidade de vida e depressão em sete estudos. O teste de degrau parece ser uma estratégia simples, rápida e segura para ser aplicado em pacientes com doenças cardíacas, contudo, para uma melhor estimativa da aptidão física são necessários mais estudos que comparem a capacidade de exercício no teste de degrau com a obtida no teste de exercício cardiopulmonar.

Although step tests are used frequently for healthy people and patients with lung diseases, this type of test is still quite rare for patients with heart diseases. The purpose of this paper is to conduct a review of literature on the use of step tests for assessing exercise capacity among patients with heart diseases. Through consulting the Medline / PubMed, LILACS and SciELO databases, 305 papers were found, with eleven included in this review: nine on patients with heart failure and two with coronary artery disease. The protocols used were the two-minute step test and the Master two-step test. Four studies compared step test performance to the metabolic equivalent, accelerometer, cycle ergometer and cardiopulmonary treadmill tests, with seven studies presenting comparisons with the performance of cognitive tasks, daily living activities, quality of life and depression. The step test seems to be a simple, fast and safe strategy for patients with heart diseases, although further studies are required for better physical fitness estimates, comparing step test exercise capacities with cardiopulmonary exercise test results.

Respostas cardiovasculares durante exercício resistido com restrição de fluxo sanguíneo / Cardiovascular responses during resistance exercise with blood flow restriction

Fundamentos: Estudos recentes mostram que o exercício resistido realizado em baixa intensidade (<50 % 1RM) com restrição de fluxo sanguíneo (RFS) pode promover modificações morfológicas/fisiológicas semelhantes aos exercícios com intensidades mais elevadas sem RFS. Objetivo: Comparar as respostas cardiovasculares e hemodinâmicas durante o exercício resistido realizado com e sem RFS. Métodos: Dezessete voluntários (25,9±6,6 anos) realizaram três séries de 15 repetições com 20 % de 1RM no exercício rosca bíceps unilateral (braço dominante) com e sem RFS. As duas sessões foram aleatoriamente realizadas no mesmo dia com intervalo de 20 min. A RFS durante o exercício foi induzida com esfigmomanômetro padrão inflado e mantido a 200 mmHg durante toda a sessão. As variáveis pressão arterial sistólica (PAS), pressão arterial diastólica (PAD), frequência cardíaca (FC), volume sistólico (VS), débito cardíaco (DC) e resistência vascular periférica total (RPT) foram aferidas de forma contínua não invasiva por medidas batimento a batimento. Resultados: Os exercícios realizados com RFS e sem RFS mostraram diferença significativa para a PAS (195,1±21,3 mmHg vs. 150,5±14,1 mmHg, respectivamente), PAD (126,7±18,6 mmHg vs. 94,9±10,3 mmHg, respectivamente) e FC (132,0±23,7 mmHg vs. 97,0±9,7 mmHg, respectivamente) somente na terceira série. Conclusão: O exercício com RFS, quando comparado com o modelo sem oclusão, não apresentou diferenças significativas até a segunda série, demonstrando ser relativamente seguro no âmbito cardiovascular.

Background: Recent studies have shown that low-intensity resistance exercises (<50% 1RM) with blood flow restriction (BFR) can cause morphological and physiological changes similar to higher-intensity exercises without BFR. Objective: To compare cardiovascular and hemodynamic responses during resistance exercises, with and without BFR. Methods: Seventeen volunteers (25.9±6.6 years) performed three sets of 15 repetitions of unilateral biceps curls (dominant arm) at 20% 1RM, with and without BFR, in two sessions undertaken at random on the same day with a 20 minute interval. BFR was induced during the exercises with a standard inflated sphygmomanometer, kept at 200 mmHg throughout the session. The systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), stroke volume (SV), cardiac output (CO) and total peripheral vascular resistance (TPR) variables were monitored continuously and non-invasively by beat-to-beat measurements. Results: Exercises with and without BFR presented significant differences only in the third set for: SBP (195.1±21.3 mmHg vs. 150.5±14.1 mmHg, respectively), DBP (126.7±18.6mmHg vs. 94.9±10.3 mmHg, respectively) and HR (132.0±23.7 mmHg vs. 97.0±9.7 mmHg, respectively). Conclusion: Exercises with BFR did not present any significant differences until the second set, compared to exercises without BFR, showing that they are relatively safe in this field.

Treatment with nebivolol combined with physical training promotes improvements in the cardiovascular responses of hypertensive rats.

The aim of this study was to determine whether exercise training combined with beta-blocker treatment promotes additional cardiovascular benefits compared with either intervention on its own. For this we used 76 Wistar rats distributed among different groups: normotensive sedentary (NS), normotensive trained (NT), normotensive sedentary treated with beta-blocker (NS_BB), normotensive trained treated with beta-blocker (NT_BB), hypertensive sedentary (HS), hypertensive trained (HT), hypertensive sedentary treated with a beta-blocker (HS_BB), and hypertensive trained rats treated with beta-blocker (HT_BB). Exercise training consisted of 4 weeks of swimming for 60 min a day, 5 days a week. Hypertension was induced with l-NAME (4 weeks), whereas the control rats received saline, and both the control and test rats received nebivolol. The animals underwent surgery to directly record their blood pressure. The HS group showed higher mean arterial pressure (MAP) (P = 0.000), systolic arterial pressure (P = 0.000), and diastolic arterial pressure (P = 0.000) compared with NS. MAP was higher in the HS compared with the HT (P = 0.002), HS_BB (P = 0.018), and HT_BB (P = 0.015) groups. Hearts from the HS group had a higher percentage of collagen compared with the NS and HS_BB groups. The HT_BB and HT groups only had a higher percentage of cardiac collagen by comparison with the HS_BB group. The HT_BB group showed higher levels of macrophages and neutrophils by comparison with the HT and HS_BB groups. Thus, treatment with a beta-blocker combined with physical training was associated with increased cardiovascular benefits over either intervention alone.

Effect of fixed and self-suggested rest intervals between sets of resistance exercise on post-exercise cardiovascular behavior / Efeito do intervalo de recuperação fixo e autossugerido entre séries do exercício resistido sobre o comportamento cardiovascular pós-esforço

This study aimed to compare differences in the number of repetitions after exercises with different rest intervals and to analyze cardiovascular parameters after resistance training. The sample comprised 10 physically active men (23±2 years). The one-repetition maximum (1RM) test was performed in the following order: bench press, guided squat bar, biceps curl and leg curl. After the 1RM test, the individual held three sessions of resistance training, on different days, with rest intervals of 1 minute, 2 minutes, and self-suggested intervals, randomized for each day. We calculated 75% of the load of the 1RM test, with three series of maximum repetitions performed to exhaustion. Cardiovascular variables were measured at rest and during 30 minutes after exercise. In the self-suggested interval, which showed an average time of rest (157±37 seconds) similar to the 2-minute interval, more repetitions were performed compared to the 1-minute interval session, with no difference in relation to the 2 minute-interval session. No difference was found in systolic blood pressure and in the high frequency (HF) component between the intervals, but post-exercise hypotension was observed in diastolic blood pressure after 10 minutes' recovery in all intervals, with a longer duration in the 2-minute interval session. After 30 minutes' recovery, an increase in the low frequency (LF) component was registered for the 2-minute interval session, and an increase in LF/HF was found at 10, 20 and 30 minutes of recovery after sessions with 1- and 2-minute intervals, demonstrating a possible predominance of sympathetic action. The self-suggested interval did not show changes in the components of heart rate variability. These findings suggest that intervals of at least 2 minutes between sets may be interesting to provide more repetitions and reduce the post-exercise sympathetic effect.

O objetivo do estudo foi comparar a diferença no número de repetições após exercícios realizados com diferentes intervalos de recuperação e analisar o comportamento cardiovascular pós-esforço. A amostra foi composta de 10 homens (23 ± 2 anos) fisicamente ativos. Foi realizado o teste de uma repetição máxima (1RM) nos exercícios supino horizontal, agachamento na barra guiada, rosca bíceps e mesa flexora, seguido de três sessões de treinamento resistido, com intervalos de recuperação de 1 min, 2 min e autossugerido. Foram realizadas três séries de repetições máximas até exaustão com 75% de 1RM. As variáveis cardiovasculares foram mensuradas em repouso e durante 30 min após o esforço. Observa-se que no intervalo autossugerido, o qual apresentou tempo médio (155±37 segundos) de descanso semelhante ao intervalo de 2 min, foram realizadas mais repetições comparadas ao intervalo de 1 min, porém não se diferenciou do intervalo de 2 min. Não houve diferença para a PAS e para o componente HF entre os intervalos, porém, houve HPE para a PAD após 10 min de recuperação em todos os intervalos, com maior duração no intervalo de 2 min. Após 30 min de recuperação observou-se aumento no componente LF para o intervalo de 2 min e aumento na razão LF/HF após 10, 20 e 30 min de recuperação nos intervalos de 1 e 2 min, demonstrando uma possível predominância da ação simpática. Porém, o intervalo autossugerido não apresentou alterações nos componentes da variabilidade da frequência cardíaca. Dessa forma, o descanso de pelo menos 2 min entre as séries pode ser interessante para proporcionar mais repetições e reduzir o efeito simpático pós-exercício.

Implicações do consumo de cafeína sobre a pressão arterial de repouso / Implications of caffeine consumption and resting blood pressure

Objetivo: O objetivo do presente estudo foi revisar a literatura sobre o comportamento na PA de repouso decorrente da ingestão crônica de cafeína, relacionando tal comportamento com possíveis mecanismos fisiológicos. Métodos: Foram realizadas buscas de artigos originais em inglês nas bases de dados Medline, Lilacs e SciELO até novembro de 2009, utilizando os termos caffeine, blood pressure, heart rate, chronic effect e cardiovascular response. Resultados: De um total de 564 estudos, apenas 29 compuseram a presente revisão. Vários estudos não observaram aumento da PA em humanos (normotensos e hipertensos) ou ratos (normotensos). Entretanto, em ratos hipertensos, os resultados dos estudos convergiram para o aumento da PA de repouso. Conclusão: Mesmo com certas lacunas em relação aos possíveis mecanismos fisiológicos envolvidos nos ajustes cardiovasculares relacionados à cafeína, nossa conclusão sugere que pessoas com hipertensão arterial sistêmica tenham cautela quanto ao uso diário dessa substância...

Exercise protects rat testis from cyclophosphamide-induced damage / O exercício físico protege o testículo de ratos de lesões teciduais induzidas por ciclofosfamida

To investigate the effect of chronic moderate exercise on male reproductive tract of Wistar rats submitted to a single dose of cyclophosphamide (CP). Animals were submitted to swimming exercise during 21 days or maintained at sedentary state. Trained (TCP) and sedentary (SCP) groups received a single dose of CP (200 mg kg-1, i.p.). Trained (TCo) and sedentary (SCo) control animals received sterile PBS. Animals were killed after one week and testis, epidydimis and seminal vesicle contend were weighted. Testis were embebbed in parafim and stained with hemotaxilin and eosin. Fifty seminiferous tubules of each animal were analyzed by Johnsen score. Mean Sertoli cells counts per tubule and Leydig cells counts per area were evaluated. CP treatment impairs body weight gain in trained and sedentary animals. Liver and seminal vesicle contend were reduced only in SCo group. SCP animals presented decreased Johnsen scores, indicating a slight toxicity over germinative cells, whereas trained (TCo and TCP) animals presented increased Johnsen scores. Training increased Sertoli cell counts and prevented their loss in TCP group. Leydig cells counts were increased in trained animals, but decreased in CP treated ones (TCP). We conclude that exercise have some protective effect on male reproductive tract submitted to a single dose of CP.

Objetivou-se investigar o efeito de exercício moderado crônico no trato reprodutivo masculino de ratos Wistar submetidos a uma dose única de ciclofosfamida (CP). Os animais foram submetidos ao exercício de natação por 21 dias ou mantidos em estado sedentário. Os grupos treinados (TCP) e sedentários (SCP) receberam uma única dose de CP (200 mg kg-1, ip). Os animais treinados (TCO) e sedentários (SCO) receberam PBS estéril. Os animais foram sacrificados após uma semana e os testículos, epidídimo e conteúdo da vesícula seminal foram pesados. As amostras foram embebidas em parafina e coradas com hematoxilina e eosina. Cinquenta túbulos seminíferos de cada animal foram analisados pelo escore Johnsen. A contagem média das células de Sertoli por túbulo e contagem das células de Leydig por área foram avaliadas. O tratamento CP prejudicou o ganho de peso corporal em animais treinados e sedentários. O fígado e o conteúdo da vesícula seminal foram reduzidos apenas no grupo SCO. Os animais SCP apresentaram menores escores de Johnsen, indicando uma toxicidade moderada sobre as células germinativas, enquanto os animais treinados (TCO e TCP) apresentaram escores de Johnsen mais altos. O treinamento aumentou a contagem de células de Sertoli e impediu a sua perda no grupo TCP. A contagem das células de Leydig foram aumentadas em animais treinados, mas reduzidas nos animais tratados com CP (TCP). Concluiu-se que o exercício tem algum efeito protetor sobre trato reprodutivo masculino de animais submetidos a uma dose única de CP.

Correlação entre o teste de caminhada de seis minutos e o teste do degrau em idosos / Correlation between the six-minute walk test and the step test in elderly

O teste do degrau pode ser uma alternativa para substituir o teste de caminhada de seis minutos quando não há um espaço físico amplo para sua realização. Existem, no entanto, poucos dados na literatura comparando e correlacionando ambos os testes. Dessa forma, o objetivo deste estudo foi correlacionar o teste de caminhada de seis minutos com o teste do degrau. Uma amostra de 38 idosos (68,5 ± 2,1 anos) realizou aleatoriamente o teste de caminhada de seis minutos e o teste do degrau, duas vezes cada teste, sendo considerado para fins de análise o maior valor obtido em cada teste. Frequência cardíaca, percepção subjetiva de esforço, de fadiga muscular e o VO2máx estimados ao final do teste do degrau foram significativamente maiores que ao final do teste de caminhada de seis minutos (p=0,001; 0,010; 0,017; 0,001, respectivamente). No presente estudo, não houve correlação entre a distância percorrida no teste de caminhada de seis minutos e o número de subidas e descidas no teste do degrau. Sendo assim, não se pode afirmar que um teste possa substituir o outro, mas levando-se em consideração os valores estatisticamente maiores para o teste do degrau nas variáveis analisadas e, por necessitar de espaço físico mínimo, sugere-se que o teste do degrau pode ser uma alternativa para a avaliação de idosos.

The step test may be an alternative to replace the six-minute walk test when there is not enough space to perform the walk test; however, there are few data in the literature comparing and correlating both tests and their interferences in physical abilities. This study aims to correlate the six-minute walk test with the step test. The sample comprised 38 active seniors (68.5 ± 2.1 years old). The six-minute walk test and the step test were randomly performed twice each and the highest value obtained for each test was taken into consideration. Heart rate, perceived exertion, perceived muscle fatigue and estimated VO2max at the end of the step test were significantly higher than in the end of the six-minute walk test (p=0.001; 0.010; 0.017; 0.001, respectively). There was no correlation between the distance in the walk test and the number of ascents and descents in the step test. Thus it cannot be stated that a test can replace the other, but taking into account the statistically higher values for the step test variables, besides the fact that the step test requires minimum physical space, this test can be an alternative to assess elderly people.

Efeito do treinamento físico e da ingestão crônica de cafeína sobre o tecido ósseo de ratos jovens / Efecto del entrenamiento físico y la ingestión crónica de cafeína sobre El hueso de ratas jóvenes / Effect of exercise training and chronic caffeine intake on bone tissue of young rats

Foram avaliados os efeitos da ingestão crônica de cafeína e exercício de natação sobre o tecido ósseo. Ratos Wistar jovens (n = 32) alocados em quatro grupos: sedentário controle (SCO), sedentário + cafeína (SCAF), treinados (TCO) e treinados + cafeína (TCAF), receberam 1 mg/ml de cafeína em água durante 30 dias (SCAF e TCAF) e foram submetidos a 21 dias de natação em intensidade moderada (TCO e TCAF). A tíbia esquerda foi submetida a ensaio biomecânico para determinação do coeficiente de rigidez, limite de elasticidade e carga máxima. A área de tecido ósseo primário e espessura do disco epifisário foram avaliadas no fêmur. Não foram observadas alterações nas propriedades biomecânicas e na deposição de tecido ósseo primário. O grupo SCAF apresentou maior espessura no disco epifisário distal. Os resultados sugerem que o treinamento moderado de natação e a ingestão de cafeína não provocaram alterações morfológicas e biomecânicas do tecido ósseo.

Effects of swimming training and chronic caffeine intake on bone tissue of young rats were investigated. Young Wistar rats were allocated into 4 groups: sedentary control (SCO), sedentary + caffeine (SCAF), trained (TCO) and trained + caffeine (TCAF); they received 1 mg/ml of caffeine diluted in water for 30 days (SCAF and TCAF) and were submitted to swimming training of moderate intensity for 21 days (TCO and TCAF). The left tibia was subjected to the biomechanical test for determination of the coefficient of stiffness, yield and maximum load. The immature bone tissue area and thickness of growth plates were evaluated in the femur. No changes were observed in biomechanical properties and the area occupied by immature bone tissue. However, SCAF group presented greater thickness in distal growth plate. The results suggest that the moderate intensity swimming training and caffeine consumption were not able to promote changes in morphology and biomechanical properties of bone tissue.

Se evaluaram los efectos del consumo crónico de cafeína y la natación em el hueso. Ratas Wistar jóvenes (n=32) divididas en cuatro grupos: sedentarios control (SCO), sedentarios + cafeína (SCAF), entrenados (TCO) y entrenados + cafeína (TCAF), recibieron 1 mg/ml de cafeína en agua durante 30 días (SCAF e TCAF) e fueron sometidos 21 días de la natación moderada. La tibia izquierda se sometió a una prueba biomecánica para determinar la coeficiente de la rigidez, el limite de elasticidad y el punto de carga máxima. El area de hueso imaturo e de la zona de la placa de crescimiento proximal e distal se analizó em el fêmur. No se observaron cambios en las propiedades biomecánicas y el déposition de hueso inmaturo. Animales SCAF tenía más grueso de la placa de crescimiento distal. Los resultados sugieren que entrenamento moderalado de la natación y el cosumo crônico de cafeína no cambió la morfología y las propiedades biomecánicas del hueso.

Inibidor direto da renina e hipertensao arterial: uma revisão / Direct renin inhibitor and hypertension: a review

A hipertensão arterial é considerada um problema de saúde pública e também um dos fatores de risco para o desenvolvimento de doenças cardiovasculares. Assim, medidas de tratamento devem ser tomadas afim de melhorar esse quadro. O inibidor direto da renina (IDR) é uma nova alternativa de tratamento anti-hipertensivo, comercializado pelo princípio ativo alisquireno. O objetivo deste estudo foi revisar a literatura quanto aos efeitos do tratamento com o IDR, na monoterapia ou terapia combinada a outras classesde anti-hipertensivos, tanto em animais quanto em seres humanos. Após o filtro de buscas na base de dados Medline, foram selecionados 11 artigosenvolvendo animais e 28 artigos envolvendo seres humanos. O IDR foi eficiente em reduzir a pressão arterial, seja administrado isoladamente seja emterapia combinada. No entanto, doses maiores parecem ser mais eficientes comparadas a doses mais baixas. Além disso, parece apresentar algumasvantagens adicionais quando comparado a outros bloqueadores do sistema renina-angiotensina, como a redução de efeitos adversos. Os mecanismosfisiológicos envolvidos nas respostas ao alisquireno ainda estão em fase de estudos, mas existem evidênciasde que há redução na atividade da renina plasmática.

Hipertensão arterial, beta-bloqueadores e exercício físico aeróbio / Hypertension, beta-blockers and aerobic exercise

Fundamento: O tratamento anti-hipertensivo com beta-bloqueador pode ser por meio de monoterapia ou terapia combinada, mas os efeitos fisiológicos do tratamento com beta-bloqueador e/ou sua interação com o exercício físico não estão bem esclarecidos. Objetivo: Revisar a literatura quanto ao tratamento com beta-bloqueador associado ou não ao exercício em animais e em humanos hipertensos. Métodos: O trabalho foi dividido em sessões com estudos de animais e com estudos de humanos. Foi realizada busca na base Medline e os principais critérios foram amostras com ratos ou humanos e artigos em inglês. Resultados: Dos trabalhos com animais, foram selecionados 13 estudos envolvendo tratamento com beta-bloqueador e três artigos que associaram o beta-bloqueador ao exercício aeróbio. Para os estudos com humanos foram selecionados 46 artigos envolvendo tratamento com beta-bloqueador e 16 estudos que associaram o beta-bloqueador ao exercício. O tratamento com beta-bloqueador reduziu a PA em animais e humanos. No entanto, pode existir diferença na magnitude da redução entre os medicamentos. Em relação à interação com o exercício, poucos estudos avaliaram o efeito crônico do treinamento. Assim, em alguns estudos, o beta-bloqueador influenciou na capacidade máxima de exercício e em outros não houve alterações significativas. Conclusão: Apesar dos diversos estudos, os mecanismos fisiológicos envolvidos na interação do beta-bloqueador com o exercício não estão bem estabelecidos.