PURPOSE To identify early cardiac dysfunctions in asymptomatic patients with Chagas' cardiomyopathy. METHODS We studied 38 male individuals: control group consisting of 20 sedentary normal individuals and Chagas' group, of 18 asymptomatic patients with Chagas' disease, with suggestive electrocardiographic alterations and normal fractional shortening (FS) on echocardiogram. Both groups were su...

We have recently demonstrated that people with a high percentage of Type I muscle fibers display a relatively high muscular efficiency when cycling. These individuals generate a relatively high muscular power output at a given steady-state level of oxygen consumption and caloric expenditure. The purpose of this study was to directly determine the extent to which differences in muscle fiber comp...

BACKGROUND Aerobic endurance is an important aspect of physical fitness that enables individuals living with HIV to endure in the work place as well as in agricultural operations in order to earn a living and improve their quality of life. However, despite high HIV prevalence rates, the aerobic endurance status of young Malawians living with HIV remains unknown. The objective of this study was ...

OBJECTIVE To assess whether exercise capacity is related to left atrial dimension (LAD) in patients with biventricular endomyocardial fibrosis. METHODS This study comprised 38 patients in sinus rhythm, with a mean age of 37.5 +/- 11.5 years (range, 11 to 59 years), 25 of whom were women. They were divided into 2 groups according to the NYHA functional class on hospital admission as follows: g...

The purpose of this study was to determine the intensity threshold needed to elicit increases in plasma aldosterone and cortisol during graded exercise in humans. Seven male volunteers performed a maximal oxygen uptake (VO2max) test on a cycle ergometer. Plasma levels of aldosterone, cortisol, angiotensin II, ACTH, and potassium were measured at rest and at each 50 W workload of the exercise te...

The aim of the present investigation was to evaluate the influence of the physical fitness of a cardiopulmonary resuscitation (CPR) provider on the performance of and physiologic response to CPR. To this end, comparisons were made of sedentary and physically active subjects in terms of CPR performance and physiologic variables. Two study groups were established: group P (n=14), composed of sede...

BACKGROUND This observational study aims to describe fitness, and objectively measured physical activity levels and patterns in 409 young black South African adults (aged 19-20 years) from Soweto, as well as to examine associations between physical activity, fitness and BMI. METHODS A sub-maximal ramped step test was used to obtain an estimate of maximal oxygen uptake (VO2max). Physical activ...

The purpose of this study was to characterize the aerobic and anaerobic capabilities of United States Cycling Federation cyclists in different categories. To determine aerobic and anaerobic power, 38 competitive road cyclists (32 males, 6 females) performed a VO2max test and a Wingate anaerobic test, respectively. Male cyclists in category II had the highest VO2max, both in absolute and relativ...

PURPOSE The purpose of this investigation was to quantify maximal aerobic power (VO2max) in soccer as a function of performance level, position, age, and time of season. In addition, the authors examined the evolution of VO2max among professional players over a 23-y period. METHODS 1545 male soccer players (22 ± 4 y, 76 ± 8 kg, 181 ± 6 cm) were tested for VO2max at the Norwegian Olympic Train...

Success in endurance running is primarily determined by maximal aerobic power (VO2max), fractional utilization, and economy (RE). Within the literature, two training modalities have been identified to improve VO2max; continuous (CT) interval-training (IT). The efficacy of IT VO2max well-trained runners remains equivocal, as does whether a dose-response relationship exists between load performed...