Cardiorespiratory abnormalities in ICU survivors of COVID-19 with postacute sequelae of SARS-CoV-2 infection are unrelated to invasive mechanical ventilation.

Postacute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (PASC) often leads to exertional intolerance and reduced exercise capacity, particularly in individuals previously admitted to an intensive care unit (ICU). However, the impact of invasive mechanical ventilation (IMV) on PASC-associated cardiorespiratory abnormalities during exercise remains poorly understood. This single-center, cross-sectional study aimed to gather knowledge on this topic. Fifty-two patients with PASC recruited ∼6 mo after ICU discharge were clustered based on their need for IMV (PASC + IMV, n = 27) or noninvasive support therapy (PASC + NIS, n = 25). Patients underwent pulmonary function and cardiopulmonary exercise testing (CPX) and were compared with a reference group (CONTROL, n = 19) comprising individuals of both sexes with similar age, comorbidities, and physical activity levels but without a history of COVID-19 illness. Individuals with PASC, irrespective of support therapy, presented with higher rates of cardiorespiratory abnormalities than CONTROL, especially dysfunctional breathing patterns, dynamic hyperinflation, reduced oxygen uptake and oxygen pulse, and blunted heart rate recovery (all P < 0.05). Only the rate of abnormal oxygen pulse was greater among PASC + IMV group than PASC + NIS group (P = 0.05). Mean estimates for all CPX variables were comparable between PASC + IMV and PASC + NIS groups (all P > 0.05). These findings indicate significant involvement of both central and peripheral factors, leading to exertional intolerance in individuals with PASC previously admitted to the ICU, regardless of their need for IMV.NEW & NOTEWORTHY We found cardiorespiratory abnormalities in ICU survivors of severe-to-critical COVID-19 with PASC to be independent of IMV need. Overall, both group of patients experienced dysfunctional breathing patterns, dynamic hyperinflation, lower oxygen uptake and oxygen pulse, and blunted heart rate responses to CPX. PASC seems to impact exertional tolerance and exercise capacity due to ventilatory inefficiency, impaired aerobic metabolism, and potential systolic and autonomic dysfunction, all of these irrespective of support therapy during ICU stay.

Physiological responses during walking in men and women with intermittent claudication.

BACKGROUND: Miyasato et al. show that peak oxygen consumption, walking economy, anaerobic threshold, and cardiovascular responses (heart rate, blood pressure, and rate pressure product) during walking were similar between men and women with peripheral artery disease and intermittent claudication. There were no differences in the physiological responses to walking between men and women with intermittent claudication. Sex per se is not a factor that demands changes in walking prescription for patients with intermittent claudication. OBJECTIVE: Peak oxygen consumption (VO2peak), anaerobic threshold, walking economy, and cardiovascular responses during walking are used to guide and monitor walking training in patients with peripheral artery disease and intermittent claudication. Women with peripheral artery disease and intermittent claudication present greater impairments than men, and evaluating training markers according to sex for decisions regarding walking prescription in this population is important. This study aimed to compare VO2peak, walking economy, anaerobic threshold, and cardiovascular responses during walking in men and women with peripheral artery disease and intermittent claudication. METHODS: Forty patients (20 men and 20 women with similar baseline characteristics) underwent a cardiopulmonary treadmill test (3.2km/h and 2% increase in slope every 2 minutes until maximal leg pain). The VO2 and rate-pressure product were assessed. Data from men and women were compared using t-tests. RESULTS: There were no significant differences between men and women (VO2peak: 15.0±4.8 versus 13.9±2.9mL∙kg-1∙min-1, p=0.38; walking economy: 9.6±2.7 versus 8.4±1.6mL∙kg-1∙min-1, p=0.09; anaerobic threshold: 10.5±3.2 versus 10.5±2.2mL∙kg-1∙min-1, p=0.98; rate pressure product at 1st stage: 13,465± 2,910 versus 14,445±4,379bpm∙mmHg, p=0.41; and rate pressure product at anaerobic threshold:13,673±3,100 versus 16,390±5,870bpm∙mmHg, p=0.08 and rate pressure product at peak exercise: 21,253±6,141 versus 21,923±7,414bpm∙mmHg, p=0.76, respectively). CONCLUSION: Men and women with peripheral artery disease and similar baseline characteristics presented similar responses to walking, suggesting that decisions regarding walking prescription and monitoring can be made regardless of sex in this specific population.

Physiological responses during walking in men and women with intermittent claudication

ABSTRACT Objective Peak oxygen consumption (VO2peak), anaerobic threshold, walking economy, and cardiovascular responses during walking are used to guide and monitor walking training in patients with peripheral artery disease and intermittent claudication. Women with peripheral artery disease and intermittent claudication present greater impairments than men, and evaluating training markers according to sex for decisions regarding walking prescription in this population is important. This study aimed to compare VO2peak, walking economy, anaerobic threshold, and cardiovascular responses during walking in men and women with peripheral artery disease and intermittent claudication. Methods Forty patients (20 men and 20 women with similar baseline characteristics) underwent a cardiopulmonary treadmill test (3.2km/h and 2% increase in slope every 2 minutes until maximal leg pain). The VO2 and rate-pressure product were assessed. Data from men and women were compared using t-tests. Results There were no significant differences between men and women (VO2peak: 15.0±4.8 versus 13.9±2.9mL∙kg-1∙min-1, p=0.38; walking economy: 9.6±2.7 versus 8.4±1.6mL∙kg-1∙min-1, p=0.09; anaerobic threshold: 10.5±3.2 versus 10.5±2.2mL∙kg-1∙min-1, p=0.98; rate pressure product at 1st stage: 13,465± 2,910 versus 14,445±4,379bpm∙mmHg, p=0.41; and rate pressure product at anaerobic threshold:13,673±3,100 versus 16,390±5,870bpm∙mmHg, p=0.08 and rate pressure product at peak exercise: 21,253±6,141 versus 21,923±7,414bpm∙mmHg, p=0.76, respectively). Conclusion Men and women with peripheral artery disease and similar baseline characteristics presented similar responses to walking, suggesting that decisions regarding walking prescription and monitoring can be made regardless of sex in this specific population.

Oxygen uptake kinetics and chronotropic responses to exercise are impaired in survivors of severe COVID-19.

The post-acute phase of coronavirus disease 2019 (COVID-19) is often marked by several persistent symptoms and exertional intolerance, which compromise survivors' exercise capacity. This was a cross-sectional study aiming to investigate the impact of COVID-19 on oxygen uptake (V̇o2) kinetics and cardiopulmonary function in survivors of severe COVID-19 about 3-6 mo after intensive care unit (ICU) hospitalization. Thirty-five COVID-19 survivors previously admitted to ICU (5 ± 1 mo after hospital discharge) and 18 controls matched for sex, age, comorbidities, and physical activity level with no prior history of SARS-CoV-2 infection were recruited. Subjects were submitted to a maximum-graded cardiopulmonary exercise test (CPX) with an initial 3-min period of a constant, moderate-intensity walk (i.e., below ventilatory threshold, VT). V̇o2 kinetics was remarkably impaired in COVID-19 survivors as evidenced at the on-transient by an 85% (P = 0.008) and 28% (P = 0.001) greater oxygen deficit and mean response time (MRT), respectively. Furthermore, COVID-19 survivors showed an 11% longer (P = 0.046) half-time of recovery of V̇o2 (T1/2V̇o2) at the off-transient. CPX also revealed cardiopulmonary impairments following COVID-19. Peak oxygen uptake (V̇o2peak), percent-predicted V̇o2peak, and V̇o2 at the ventilatory threshold (V̇o2VT) were reduced by 17%, 17%, and 12% in COVID-19 survivors, respectively (all P < 0.05). None of the ventilatory parameters differed between groups (all P > 0.05). In addition, COVID-19 survivors also presented with blunted chronotropic responses (i.e., chronotropic index, maximum heart rate, and heart rate recovery; all P < 0.05). These findings suggest that COVID-19 negatively affects central (chronotropic) and peripheral (metabolic) factors that impair the rate at which V̇o2 is adjusted to changes in energy demands.NEW & NOTEWORTHY Our findings provide novel data regarding the impact of COVID-19 on submaximal and maximal cardiopulmonary responses to exercise. We showed that V̇o2 kinetics is significantly impaired at both the onset (on-transient) and the recovery phase (off-transient) of exercise in these patients. Furthermore, our results suggest that survivors of severe COVID-19 may have a higher metabolic demand at a walking pace. These findings may partly explain the exertional intolerance frequently observed following COVID-19.

Home-Based Exercise Training During COVID-19 Pandemic in Post-Bariatric Patients: a Randomized Controlled Trial.

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Post-exercise Hypotension Following a Single Bout of High Intensity Interval Exercise vs. a Single Bout of Moderate Intensity Continuous Exercise in Adults With or Without Hypertension: A Systematic Review and Meta-Analysis of Randomized Clinical Trials.

Background: Post-exercise hypotension (PEH) is an important tool in the daily management of patients with hypertension. Varying the exercise parameters is likely to change the blood pressure (BP) response following a bout of exercise. In recent years, high-intensity interval exercise (HIIE) has gained significant popularity in exercise-based prevention and rehabilitation of clinical populations. Yet, to date, it is not known whether a single session of HIIE maximizes PEH more than a bout of moderate-intensity continuous exercise (MICE). Objective: To compare the effect of HIIE vs. MICE on PEH by means of a systematic review and meta-analysis. Methods: A systematic search in the electronic databases MEDLINE, Embase, and SPORTDiscus was conducted from the earliest date available until February 24, 2020. Randomized clinical trials comparing the transient effect of a single bout of HIIE to MICE on office and/or ambulatory BP in humans (≥18 years) were included. Data were pooled using random effects models with summary data reported as weighted means and 95% confidence interval (CIs). Results: Data from 14 trials were included, involving 18 comparisons between HIIE and MICE and 276 (193 males) participants. The immediate effects, measured as office BP at 30- and 60-min post-exercise, was similar for a bout of HIIE and MICE (p > 0.05 for systolic and diastolic BP). However, HIIE elicited a more pronounced BP reduction than MICE [(-5.3 mmHg (-7.3 to -3.3)/ -1.63 mmHg (-3.00 to -0.26)] during the subsequent hours of ambulatory daytime monitoring. No differences were observed for ambulatory nighttime BP (p > 0.05). Conclusion: HIIE promoted a larger PEH than MICE on ambulatory daytime BP. However, the number of studies was low, patients were mostly young to middle-aged individuals, and only a few studies included patients with hypertension. Therefore, there is a need for studies that involve older individuals with hypertension and use ambulatory BP monitoring to confirm HIIE's superiority as a safe BP lowering intervention in today's clinical practice. Systematic Review Registration: PROSPERO (registration number: CRD42020171640).

Benefits of Home-Based Exercise Training Following Critical SARS-CoV-2 Infection: A Case Report.

In the current scenario, in which an elevated number of COVID-19 survivors present with severe physical deconditioning, exercise intolerance, persistent symptoms, and other post-acute consequences, effective rehabilitation strategies are of utmost relevance. In this study, we report for the first time the effect of home-based exercise training (HBET) in a survivor patient from critical COVID-19 illness. A 67-year-old woman who had critical COVID-19 disease [71 days of hospitalization, of which 49 days were in the intensive care unit (ICU) with invasive mechanical ventilation due to respiratory failure] underwent a 10-week HBET aiming to recovering overall physical condition. Before and after the intervention, we assessed cardiopulmonary parameters, skeletal muscle strength and functionality, fatigue severity, and self-reported persistent symptoms. At baseline (3 months after discharge), she presented with severe impairment in cardiorespiratory functional capacity (<50% age predicted VO2peak). After the intervention, remarkable improvements in VO2peak (from 10.61 to 15.48 mL·kg-1·min-1, Δ: 45.9%), oxygen uptake efficiency slope (OUES; from 1.0 to 1.3 L·min-1, Δ: 30.1%), HR/VO2 slope (from 92 to 52 bpm·L-1, Δ: -43.5%), the lowest VE/VCO2 ratio (from 35.4 to 32.9 L·min-1, Δ: -7.1%), and exertional dyspnea were observed. In addition, handgrip strength (from 22 to 27 kg, Δ: 22.7%), 30-s Sit-to-Stand (30-STS; from 14 to 16 repetitions, Δ:14.3%), Timed-Up-and-Go (TUG; from 8.25 to 7.01 s, Δ: -15%) performance and post-COVID functional status (PCFS) score (from 4 to 2) were also improved from baseline to post-intervention. Self-reported persistent symptoms were also improved, and Fatigue Severity Scale (FSS) score decreased (from 4 to 2.7) from baseline to post-intervention. This is the first evidence that a semi-supervised, HBET program may be safe and potentially effective in improving cardiorespiratory and physical functionality in COVID-19 survivors. Controlled studies are warranted to confirm these findings.

Cardiovascular Responses during and after Maximal Walking in Men and Women with Symptomatic Peripheral Artery Disease.

BACKGROUND: Walking is recommended for patients with peripheral arterial disease (PAD). It has been shown that patients with PAD present sharper increases in blood pressure (BP) and heart rate (HR) during maximal walking when compared with healthy subjects. Additionally, women with PAD present a worse physiological profile, and it is possible that they may present higher cardiovascular load during and after a bout of maximal walking than men. Thus, the objective of this study was to compare cardiovascular and autonomic responses during and after maximal walking between men and women with PAD and intermittent claudication (IC). METHODS: Forty patients with PAD and IC (20 men and 20 women) underwent, in random order, 2 sessions: control (standing on treadmill) and exercise (maximal treadmill walking test with Gardner's protocol). During the exercise, HR and BP were measured. Before and after the sessions, cardiovascular variables (BP HR, cardiac output, peripheral vascular resistance, and stroke volume) and autonomic modulation (HR and BP variabilities and baroreflex sensitivity) were assessed. In addition, an ambulatory BP monitoring was recorded after each session. RESULTS: Men and women presented similar maximal walking capacity. During the walking test, HR and systolic BP increased similarly in men and women. After the maximal walking, cardiovascular and autonomic responses did not differ between the genders. In addition, postintervention ambulatory BP parameters were also similar in men and women. Therefore, in men and women, maximal walking similarly reduced clinic systolic BP and stroke volume, and increased HR and total power of HR variability during the recovery period. CONCLUSIONS: Men and women with PAD and IC present similar cardiovascular and autonomic responses during and after maximal walking.

Social isolation during the COVID-19 pandemic can increase physical inactivity and the global burden of cardiovascular disease.

Emerging data indicate a substantial decrease in global physical activity levels during the period of social isolation adopted worldwide to contain the spread of the coronavirus disease 2019 (COVID-19). Confinement-induced decreases in physical activity levels and increases in sedentary behavior may provoke a rapid deterioration of cardiovascular health and premature deaths among populations with increased cardiovascular risk. Even short-term (1-4 wk) inactivity has been linked with detrimental effects in cardiovascular function and structure and increased cardiovascular risk factors. In this unprecedented and critical scenario, home-based physical activity programs arise as a clinically relevant intervention to promote health benefits to cardiac patients. Many studies have demonstrated the feasibility, safety, and efficacy of different models of home-based exercise programs in the primary and secondary prevention of cardiovascular diseases and major cardiovascular events among different populations. This body of knowledge can inform evidence-based policies to be urgently implemented to counteract the impact of increased physical inactivity and sedentary behavior during the COVID-19 outbreak, thereby alleviating the global burden of cardiovascular disease.

A randomized controlled trial comparing home-based isometric handgrip exercise versus endurance training for blood pressure management.

Aerobic endurance exercise (AEX) is an effective treatment in the prevention and management of high blood pressure (BP). Growing evidence suggests potential benefits from isometric handgrip (IHG) exercise, which may promote similar or even larger reductions in BP than AEX. We compared the effects of home-based AEX and home-based IHG on BP. Sixty healthy individuals (31 men; mean age, 33.1 years; mean BP, 126.9 ± 1.6/84.7 ± 1.1 mm Hg) were randomized to IHG, AEX, or a control group. Both exercise interventions were performed in the home environment. The IHG group performed daily 4 × 2 minutes sustained grips at 30% of maximal volitional contraction. Participants in the AEX group were advised to perform at least 150 min/wk of aerobic exercise at moderate intensity. Outcome measurements were assessed at baseline and 8 weeks of follow-up. Compared with the control group, AEX resulted in a larger reduction in ambulatory BP; both AEX and IHG exercise tended to induce larger reductions in office systolic BP, and office diastolic BP was significantly more reduced after AEX but not IHG exercise. Responses to training were not significantly different between both the exercise interventions. Eight weeks of home-based AEX results in significant reductions in both ambulatory BP and office BP in healthy adults, whereas IHG reduces only office BP.

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.

Blood Pressure and Hemodynamic Adaptations after a Training Program in Young Individuals with Down Syndrome.

BACKGROUND: Cardiovascular diseases affect people worldwide. Individuals with Down Syndrome (DS) have an up to sixteen-time greater risk of mortality from cardiovascular diseases. OBJECTIVE: To evaluate the effects of aerobic and resistance exercises on blood pressure and hemodynamic variables of young individuals with DS. METHODS: A total of 29 young individuals with DS participated in the study. They were divided into two groups: aerobic training (AT) (n = 14), and resistance training (TR) (n = 15). Their mean age was 15.7 ± 2.82 years. The training program lasted 12 weeks, and had a frequency of three times a week for AT and twice a week for RT. AT was performed in treadmill/ bicycle ergometer, at an intensity between 50%-70% of the HR reserve. RT comprised nine exercises with three sets of 12 repetition-maximum. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP) and hemodynamic variables were assessed beat-to-beat using the Finometer device before/after the training program. Descriptive analysis, the Shapiro-Wilk test to check the normality of data, and the two-way ANOVA for repeated measures were used to compare pre- and post-training variables. The Pearson's correlation coefficient was calculated to correlate hemodynamic variables. The SPSS version 18.0 was used with the significance level set at p < 0.05. RESULTS: After twelve weeks of aerobic and/or resistance training, significant reductions in variables SBP, DBP and MBP were observed. CONCLUSION: This study suggests a chronic hypotensive effect of moderate aerobic and resistance exercises on young individuals with DS.

Blood Pressure and Hemodynamic Adaptations after a Training Program in Young Individuals with Down Syndrome / Pressão Arterial e Adaptações Hemodinâmicas após Programa de Treinamento em Jovens com Síndrome de Down

Background: Cardiovascular diseases affect people worldwide. Individuals with Down Syndrome (DS) have an up to sixteen-time greater risk of mortality from cardiovascular diseases. Objective: To evaluate the effects of aerobic and resistance exercises on blood pressure and hemodynamic variables of young individuals with DS. Methods: A total of 29 young individuals with DS participated in the study. They were divided into two groups: aerobic training (AT) (n = 14), and resistance training (TR) (n = 15). Their mean age was 15.7 ± 2.82 years. The training program lasted 12 weeks, and had a frequency of three times a week for AT and twice a week for RT. AT was performed in treadmill/ bicycle ergometer, at an intensity between 50%-70% of the HR reserve. RT comprised nine exercises with three sets of 12 repetition-maximum. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP) and hemodynamic variables were assessed beat-to-beat using the Finometer device before/after the training program. Descriptive analysis, the Shapiro-Wilk test to check the normality of data, and the two-way ANOVA for repeated measures were used to compare pre- and post-training variables. The Pearson’s correlation coefficient was calculated to correlate hemodynamic variables. The SPSS version 18.0 was used with the significance level set at p < 0.05. Results: After twelve weeks of aerobic and/or resistance training, significant reductions in variables SBP, DBP and MBP were observed. Conclusion: This study suggests a chronic hypotensive effect of moderate aerobic and resistance exercises on young individuals with DS. .

Fundamento: As doenças cardiovasculares atingem as pessoas em todo o mundo. Pessoas com Síndrome de Down (SD) apresentam um risco até dezesseis vezes maior de mortalidade por doenças cardiovasculares. Objetivo: Avaliar os efeitos do exercício aeróbio e resistido na pressão arterial e variáveis hemodinâmicas de jovens com SD. Métodos: Participaram do estudo 29 jovens com SD, divididos em dois grupos: (TA) Treinamento Aeróbio (n = 14) e (TR) Treinamento Resistido (n = 15), idade 15,7 ± 2,82 anos. O programa de treinamento teve doze semanas, frequência de três vezes por semana para TA, e duas vezes, para TR. TA foi realizado com esteira/bicicleta, intensidade entre 50%-70% da FC de reserva. TR teve nove exercícios com três séries de doze repetições máximas. Avaliações de Pressão Arterial Sistólica (PAS), Pressão Arterial Diastólica PAD), Pressão Arterial Média (PAM) e variáveis hemodinâmicas foram realizadas batimento a batimento por meio do Finometer antes/após o programa de treinamento. Foram usados estatística descritiva, teste de Shapiro-Wilk para verificação da normalidade dos dados e teste ANOVA two-way para medidas repetidas para a comparação das variáveis pré e pós-treinamento. Para correlacionar as variáveis hemodinâmicas, foi calculado o coeficiente de correlação de Pearson. Utilizou-se o programa estatístico SPSS versão 18.0, adotando nível de significância (p < 0,05). Resultados: Após doze semanas de treinamento, aeróbio e/ou resistido, ocorreram reduções significativas pós‑intervenção nas variáveis de PAS, PAD e PAM. Conclusão: Sugere um efeito hipotensivo crônico do exercício aeróbio e resistido moderado em jovens com SD. .

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.

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.

Hipotensão pós-exercício aeróbio e resistido em indivíduos com lesão medular / Post-exercise hypotension following aerobic and resistance exercises in individuals with spinal cord injury

O objetivo deste estudo foi analisar a hipotensão pós-exercício (HPE) aeróbio e resistido em cinco indivíduos com lesão medular torácica do sexo masculino e fisicamente ativos (28.6±6.2 anos; 57.4±13.2 kg; 1.71±0.04 m; VO2pico: 29.46±4.3 ml/kg/min). Primeiramente os participantes realizaram exercício aeróbio tocando a cadeira de rodas por 30 minutos em intensidade de 50-70% da frequência cardíaca de reserva. Após 48-72 horas, realizaram a sessão de exercício resistido, com 3 séries de 12 repetições a 60% de uma repetição máxima. Cada participante teve sua pressão arterial (PA) mensurada em repouso e recuperação. Para o exercício aeróbio, foi encontrada HPE para pressão arterial sistólica (PAS) depois dos 30 minutos de recuperação. Já para o exercício resistido não foi encontrada HPE em nenhum momento. Os resultados demonstram a importância do exercício aeróbio para o controle e redução da PA em indivíduos com lesão medular.

The objective of this study was to monitor the post-exercise hypotension (PEH) of five physically active men (28.6±6.2 years old; 57.4±13.2 kg; 1.71±0.04 m; VO2peak: 29.46±4.3 l/kg/min) with thoracic spinal cord injury following aerobic and resistance exercises. First, the participants performed aerobic exercise by pushing their wheelchairs for 30 minutes at an intensity of 50-70% of the heart rate reserve (HRR). After 48-72 hours, the men performed a session of resistance exercises, three sets of 12 repetitionsat 60% intensity. Each participant's blood pressure (BP) was checked at rest and recovery. For the aerobic exercise, PEH registered for the systolic blood pressure (SBP) after 30 minutes of recovery. For the resistance exercise, no PEH was found at any variable. These results convey the importance of aerobic exercise for controlling and reducing BP in individuals with spinal cord injury.

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.

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.