The effect of prior exercise intensity on oxygen uptake kinetics during high-intensity running exercise in trained subjects

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

What is the stimulus for the excavation of fungus chamber in leaf-cutting ants?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Differences in metabolic and inflammatory responses in lower and upper body high-intensity intermittent exercise

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Prior Heavy-Intensity Exercise's Enhancement of Oxygen-Uptake Kinetics and Short-Term High-Intensity Exercise Performance Independent of Aerobic-Training Status

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Adaptation and penetration of resin-based root canal sealers in root canals irradiated with high-intensity lasers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The slope of the VO2 slow component is associated with exercise intolerance during severe-intensity exercise

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Aerobic fitness level modulates the effects of prior supramaximal exercise on pulmonary VO2 response during moderate-intensity exercise

The aim of this study was to analyze the influence of aerobic fitness on the effects of prior exercise on VO2response during subsequent moderate-intensity exercise. After determination of the lactate threshold (LT) and maximal VO2 (VO2max). 14 untrained subjects (UG) and 14 well-trained cyclists (TG) performed on different days and in random order, rest to moderate-intensity exercise transitions (6 minutes at 80% of LT), preceded by either no prior exercise or prior supramaximal exercise (PSE: two bouts of 1 minute at 120% of VO2max, with a 1-minute rest in between). Baseline VO2 was significantly increased (p<0.05) by PSE in both groups (UG: 0.39 ± 0.06 vs. 0.51 ± 0.15 L·min -1;TG: 0.37 ± 0.06 vs. 0.58 ± 0.14 L·min -1). In the TG group, the steady state VO2 was significantly increased by PSE (TG: 2.21 ± 0.38 vs. 2.07 ± 0.27 L·min-1, p<0.05; UG: 1.60 ± 0.27 vs. 1.60 ± 0.29 L· min-1, p>0.05). It can be concluded that aerobic fitness level influences the effects of PSE on VO2 response during moderate-intensity exercise. [J Exerc Sci Fit • Vol 7 • No 1 • 48-54 • 2009].

Differences in acoustic and perceptual parameters of the voice between elderly and young women at habitual and high intensity

The present study aimed to compare elderly and young female voices in habitual and high intensity. The effect of increased intensity on the acoustic and perceptual parameters was assessed. Sound pressure level, fundamental frequency, jitter, shimmer, and harmonic to noise ratio were obtained at habitual and high intensity voice in a group of 30 elderly women and 30 young women. Perceptual assessment was also performed. Both groups demonstrated an increase in sound pressure level and fundamental frequency from habitual voice to high intensity voice. No differences were found between groups in any acoustic variables on samples recorded with habitual intensity level. No significant differences between groups were found in habitual intensity level for pitch, hoarseness, roughness, and breathiness. Asthenia and instability obtained significant higher values in elderly than young participants, whereas, the elderly demonstrated lower values for perceived tension and loudness than young subjects. Acoustic and perceptual measures do not demonstrate evident differences between elderly and young speakers in habitual intensity level. The parameters analyzed may lack the sensitivity necessary to detect differences in subjects with normal voices. Phonation with high intensity highlights differences between groups, especially in perceptual parameters. Therefore, high intensity should be included to compare elderly and young voice.

Low intensity physical exercise attenuates cardiac remodeling and myocardial oxidative stress and dysfunction in diabetic rats

We evaluated the effects of a low intensity aerobic exercise protocol on cardiac remodeling and myocardial function in diabetic rats. Wistar rats were assigned into four groups: sedentary control (C-Sed), exercised control (C-Ex), sedentary diabetes (DM-Sed), and exercised diabetes (DM-Ex). Diabetes was induced by intraperitoneal injection of streptozotocin. Rats exercised for 9 weeks in treadmill at 11 m/min, 18 min/day. Myocardial function was evaluated in left ventricular (LV) papillary muscles and oxidative stress in LV tissue. Statistical analysis was given by ANOVA or Kruskal-Wallis. Echocardiogram showed diabetic groups with higher LV diastolic diameter-to-body weight ratio and lower posterior wall shortening velocity than controls. Left atrium diameter was lower in DM-Ex than DM-Sed (C-Sed: 5.73 ± 0.49; C-Ex: 5.67 ± 0.53; DM-Sed: 6.41 ± 0.54; DM-Ex: 5.81 ± 0.50 mm; P < 0.05 DM-Sed vs C-Sed and DM-Ex). Papillary muscle function was depressed in DM-Sed compared to C-Sed. Exercise attenuated this change in DM-Ex. Lipid hydroperoxide concentration was higher in DM-Sed than C-Sed and DM-Ex. Catalase and superoxide dismutase activities were lower in diabetics than controls and higher in DM-Ex than DM-Sed. Glutathione peroxidase activity was lower in DM-Sed than C-Sed and DM-Ex. Conclusion. Low intensity exercise attenuates left atrium dilation and myocardial oxidative stress and dysfunction in type 1 diabetic rats.

Exercise tolerance can be enhanced through a change in work rate within the severe intensity domain: work above critical power is not constant

The characterization of the hyperbolic power-time (P-tlim) relationship using a two-parameter model implies that exercise tolerance above the asymptote (Critical Power; CP), i.e. within the severe intensity domain, is determined by the curvature (W') of the relationship. The purposes of this study were (1) to test whether the amount of work above CP (W>CP) remains constant for varied work rate experiments of high volatility change and (2) to ascertain whether W' determines exercise tolerance within the severe intensity domain. Following estimation of CP (208 ± 19 W) and W' (21.4 ± 4.2 kJ), 14 male participants (age: 26 ± 3; peak [Formula: see text]: 3708 ± 389 ml.min-1) performed two experimental trials where the work rate was initially set to exhaust 70% of W' in 3 ('THREE') or 10 minutes ('TEN') before being subsequently dropped to CP plus 10 W. W>CP for TEN (104 ± 22% W') and W' were not significantly different (P>0.05) but lower than W>CP for THREE (119 ± 17% W', P<0.05). For both THREE (r = 0.71, P<0.01) and TEN (r = 0.64, P<0.01), a significant bivariate correlation was found between W' and tlim. W>CP and tlim can be greater than predicted by the P-tlim relationship when a decrement in the work rate of high-volatility is applied. Exercise tolerance can be enhanced through a change in work rate within the severe intensity domain. W>CP is not constant.

High-intensity resistance training attenuates dexamethasone-induced muscle atrophy

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Short-term low-intensity blood flow restricted interval training improves both aerobic fitness and muscle strength

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Administração de maltodextrina em cavalos submetidos a teste de exercício progressivo e a exercícios sequenciais de alta intensidade e curta duração em esteira

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

High-intensity interval training and hypertension: Maximizing the benefits of exercise?

Essential arterial hypertension is the most common risk factor for cardiovascular morbidity and mortality. Regular exercise is a well-established intervention for the prevention and treatment of hypertension. Continuous moderate-intensity exercise training (CMT) that can be sustained for 30 min or more has been traditionally recommended for hypertension prevention and treatment. On the other hand, several studies have shown that high-intensity interval training (HIT), which consists of several bouts of high-intensity exercise (~85% to 95% of HRMAX and/or VO2MAX lasting 1 to 4 min interspersed with intervals of rest or active recovery, is superior to CMT for improving cardiorespiratory fitness, endothelial function and its markers, insulin sensitivity, markers of sympathetic activity and arterial stiffness in hypertensive and normotensive at high familial risk for hypertension subjects. This compelling evidence suggesting larger beneficial effects of HIT for several factors involved in the pathophysiology of hypertension raises the hypothesis that HIT may be more effective for preventing and controlling hypertension.