This study evaluates the validity and reliability of the Baecke questionnaire on habitual physical activity when applied to a population of HIV/AIDS subjects. Validity was determined by comparing measurements for 30 subjects of peak oxygen uptake, peak workload, and energy expenditure with scores for occupational physical activity (OPA), physical exercise in leisure (PEL), leisure and locomotion activities (LLA), and total score (TS). Reliability was determined by testing and retesting 29 subjects at intervals of 15-30 days. Validity was evaluated with the Pearson correlation and reliability analyses were done using the intraclass correlation, paired Student t-test, and Bland-Altman methods. Peak VO2 and peak workload had significant correlation with PEL (r = 0.41; r = 0.43; respectively). Energy expenditure had a significant correlation with OPA (r = 0.64). The intraclass coefficients were 0.70 or more for OPA, PEL and TS. There was no difference in OPA, PEL, LLA and TS between the two evaluations. The Bland-Altman methods showed that there was good agreement between the measurements for all habitual physical activities scores. Results show that the Baecke questionnaire is valid for the evaluation of habitual physical activity among people living with HIV/AIDS.

We investigated the influence of sport modalities in resting bradycardia and its mechanisms of control in highly trained athletes. In addition, the relationships between bradycardia mechanisms and cardiac structural adaptations were tested. Professional male athletes (13 runners, 11 cyclists) were evaluated. Heart rate (HR) was recorded at rest on beat-to-beat basis (ECG). Selective pharmacological blockade was performed with atropine and esmolol. Vagal effect, intrinsic heart rate (IHR), parasympathetic (n) and sympathetic (m) modulations, autonomic influence (AI) and autonomic balance (Abal) were calculated. Plasmatic norepinephrine (high-pressure liquid chromatography) and cardiac structural adaptations (echocardiography) were evaluated. Runners presented lower resting HR, higher vagal effect, parasympathetic modulation (n), AI and IHR than cyclists (P<0.05). Abal, sympathetic modulation (m) and norepinephrine level were similar within athletes regardless of modality. The cardiac chambers were also similar between runners and cyclists (P=0.30). However, cyclists displayed higher septum and posterior wall thickness than runners (P=0.04). Further analysis showed a trend towards inverse correlation between IHR with septum wall thickness and posterior wall thickness (P=0.056). Type of sport influences the resting bradycardia level and its mechanisms of control in professional athletes. Resting bradycardia in runners is mainly dependent on an autonomic mechanism. In contrast, a cyclist's resting bradycardia relies on a non-autonomic mechanism probably associated with combined eccentric and concentric hypertrophy.

Exercise intensity is a key parameter for exercise prescription but the optimal range for individuals with high cardiorespiratory fitness is unknown. The aims of this study were (1) to determine optimal heart rate ranges for men with high cardiorespiratory fitness based on percentages of maximal oxygen consumption (%VO(2max)) and reserve oxygen consumption (%VO(2reserve)) corresponding to the ventilatory threshold and respiratory compensation point, and (2) to verify the effect of advancing age on the exercise intensities. Maximal cardiorespiratory testing was performed on 210 trained men. Linear regression equations were calculated using paired data points between percentage of maximal heart rate (%HR(max)) and %VO(2max) and between percentage of heart rate reserve (%HRR) and %VO(2reserve) attained at each minute during the test. Values of %VO(2max) and %VO(2reserve) at the ventilatory threshold and respiratory compensation point were used to calculate the corresponding values of %HR(max) and %HRR, respectively. The ranges of exercise intensity in relation to the ventilatory threshold and respiratory compensation point were achieved at 78-93% of HR(max) and 70-93% of HRR, respectively. Although absolute heart rate decreased with advancing age, there were no age-related differences in %HR(max) and %HRR at the ventilatory thresholds. Thus, in men with high cardiorespiratory fitness, the ranges of exercise intensity based on %HR(max) and %HRR regarding ventilatory threshold were 78-93% and 70-93% respectively, and were not influenced by advancing age.

Left-ventricular hypertrophy caused by exercise training is exacerbated in homozygous TT individuals with angiotensinogen polymorphism.

Objective: To characterize electrocardiographic and functional cardiac parameters and cardiopulmonary responses to exercise in longdistance Brazilian runners monitored at the Sport and Exercise Cardiology Outpatient Facility of a tertiary care hospital. Methods:Of an initial population of 443 male and female athletes of different sport modalities, we assessed 162 (37%) long-distance male runners, aged from 14 to 67. Electrocardiographic (12 leads) and echocardiographic (M-mode and two-dimensional) parameters were recorded at rest. Cardiopulmonary responses were evaluated on a treadmill with a ramp protocol.Results: Metabolic alterations and cardiovascular diseases were diagnosed in 17% and 9% of the runners, respectively. Sinus bradycardia and left ventricular hypertrophy were observed in 62% and 33% of the runners, respectively. Structural alterations such as ventricular cavity > 55mm, relative wall thickness > 0.44, and ventricular mass index > 134g/m2 were found in 15%, 11% and 7% of the runners, respectively. Ejection fraction < 55% was observed in 4% of the runners. Peak oxygen uptake (VO2peak) decreased as of the age of 41, although the anaerobic threshold relative to the VO2peak remained unchanged with age. Conclusion:Resting bradycardia and left ventricular hypertrophy are the most frequent cardiovascular adaptations in Brazilian long distance runners monitored by the Sport and Exercise Cardiology Outpatient Facility. Although VO2peak decreases after the age of 41, the relative oxygen uptake at the anaerobic threshold of these runners remained unchanged.

Background: Little is known about cardiorespiratory and metabolic response in healthy children during progressive maximal exercise test.

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Background Moderate intensity continuous exercise (MICT) has been shown to reduce muscle sympathetic nerve activity (MSNA) in heart failure patients with reduced ejection fraction (HFrEF). However, the effects of high‐intensity interval training (HIIT) on MSNA in HFrEF patients are unknown. We hypothesized that reductions in MSNA would be greater following HIIT than MICT and correspond with improvements in peripheral vascular function. Methods HFrEF patients (30 ‐ 65 years), left ventricular ejection fraction ≤ 40%, Functional Classes II–III, were randomized into HIIT, MICT or no training (NT) three times/week for 12 weeks. MSNA was assessed by microneurography. Brachial artery flow‐mediated dilation (FMD), blood flow and vascular conductance were assessed by ultrasonography, blood pressure (BP) and heart rate (HR) by plethysmography and peak oxygen uptake (V̇O2peak) by a cardiopulmonary exercise test. Results Both, HIIT and MICT, led to reductions in MSNA (frequency and incidence burst) relative to NT (p<0.05). However, the reduction in MSNA was more pronounced following HIIT than MICT (p<0.05). Increases in brachial artery FMD, resting blood flow and conductance were also greater following HIIT than MICT (p<0.05), while V̇O2peak increased similarly following HIIT and MICT relative to NT. No changes in BP or HR were observed in either exercise condition. Further analysis showed a negative correlation between changes in MSNA and FMD following the interventions (r=−0.60, p=0.005). Conclusion Our findings indicate that 12 weeks of HIIT is superior to MICT in reducing sympathetic overactivity and improving vascular function in patients with HFrEF, despite similar increases in exercise capacity. Support or Funding Information FAPESP Grants (2014/11671‐6 and 2017/25613‐6)