Effects of different intensities of physical exercise on insulin sensitivity and protein kinase B/Akt activity in skeletal muscle of obese mice

Objetivo: Investigar os efeitos do exercício físico agudo com diferentes intensidades sobre a sensibilidade à insulina e a atividade da proteína quinase B/Akt no músculo esquelético de camundongos obesos. Método: Foram utilizados camundongos Swiss, divididos aleatoriamente em quatro grupos, que receberam dieta padrão (grupo controle) ou dieta hiperlipídica (grupos obeso sedentário e grupos obesos exercitados 1 e 2), por período de 12 semanas. Dois diferentes protocolos de exercício foram utilizados: natação durante 1 hora com ou sem sobrecarga de 5% da massa corporal. O teste de tolerância à insulina foi realizado para estimar a sensibilidade à insulina. E os níveis protéicos da proteína quinase B/Akt e de sua fosforilação foram determinados no músculo esquelético dos camundongos, através da técnica de Western blot. Resultado: Uma sessão de exercício físico foi capaz de inibir a resistência à insulina em decorrência de uma dieta hiperlipídica. Foi possível demonstrar um aumento na fosforilação da proteína quinase B/Akt, melhora da sinalização da insulina e redução da glicemia de jejum nos camundongos que realizaram 1 hora de natação sem sobrecarga adicional e nos camundongos que realizaram 1 hora de natação com sobrecarga adicional de 5% de sua massa corporal. Entretanto, não houve diferença significativa entre os grupos que realizaram o exercício em diferentes intensidades. Conclusão: Independente da intensidade, o exercício físico aeróbio conseguiu aumentar a sensibilidade à insulina e a fosforilação da proteína quinase B/Akt, revelando ser uma boa forma de tratamento e prevenção do diabetes tipo 2.

The psychobiological model: a new explanation to intensity regulation and (in)tolerance in endurance exercise

The mechanisms underpinning fatigue and exhaustion, and the specific sources of exercise-endurance intensity regulation and (in)tolerance have been investigated for over a century. Although several scientific theories are currently available, over the past five years a new framework called Psychobiological model has been proposed. This model gives greater attention to perceptual and motivational factors than its antecedents, and their respective influence on the conscious process of decision-making and behavioral regulation. In this review we present experimental evidences and summarize the key points of the Psychobiological model to explain intensity regulation and (in)tolerance in endurance exercise. Still, we discuss how the Psychobiological model explains training-induced adaptations related to improvements in performance, experimental manipulations, its predictions, and propose future directions for this investigative area. The Psychobiological model may give a new perspective to the results already published in the literature, helping scientists to better guide their research problems, as well as to analyze and interpret new findings more accurately.

Exercise training decreases mitogen-activated protein kinase phosphatase-3 expression and suppresses hepatic gluconeogenesis in obese mice

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

Effects of an isotonic beverage on autonomic regulation during and after exercise

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

Exercise training as treatment in cancer cachexia

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

Aerobic Training Prevents Dexamethasone-Induced Peripheral Insulin Resistance

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

High intensity exercise training worsens alveolar destruction in pulmonary emphysema rats

OBJECTIVE: Investigation of standard intensities of physical exercise is important to better comprehend and develop rehabilitation programs for emphysema. We aimed to evaluate the effects of different intensities (moderate and high-intensity) of physical exercise on the development of a protease-induced (papain intratracheal instillation) emphysema in rats. METHODS: Male Wistar rats were randomly separated into five groups that received intratracheal instillation of papain solution or vehicle: (i) papain high intensity exercise, (ii) papain moderate exercise, (iii) saline high intensity exercise, (iv) saline sedentary and (v) papain sedentary. Forty days after intratracheal instillation, the exercise groups were submitted to an exercise-training protocol on a treadmill during 10 weeks, 5 days/week, at 0.9 km/h (Papain and saline high exercise), or at 0.6 km/h (papain moderate exercise).We measured respiratory system elastance and resistance, the collagen fiber lung parenchyma, and the pulmonary mean linear intercept. RESULTS: All animal groups that received papain instillation presented higher alveolar wall destruction compared to animals that received only saline solution. The papain high intensity exercise group presented higher values of mean linear intercept compared to emphysema groups that were trained at a moderate intensity or not submitted to exercise. CONCLUSION: High intensity exercise training worsened alveolar destruction in an experimental model of emphysema in rats when compared to moderate intensity exercise, or to no exercise.

Cardiovascular responses induced by acute video game boxing performance in healthy women

BACKGROUND: Previous studies suggested that some interactive video games induce cardiovascular responses. However, some different styles of video games have not been investigated. OBJECTIVE: We aimed to evaluate cardiovascular responses induced by video game boxing performance in healthy women. METHOD: We evaluated ten female sedentary volunteers, aged 20.9 ± 1.4 years, weight 58.7 ± 8.0 kg, height 163.2 ± 5.4cm. All subjects were weighed and measured. Their heart rate, blood pressure and lactate levels were recorded before and after video game performance. The volunteers played a Sony video game (Nintendo® Wii) by using the boxing method, in which all volunteers played for 10 minutes without interruption. At the end of the game the volunteers were reassessed using the same parameters mentioned above. RESULTS: At the end of the video game boxing performance we observed highly significant increases of lactate production (p < 0.0035) and the double product (heart rate vs. systolic blood pressure) was also higher (p < 0.0001). Both parameters indicate that the performance increased demands of the cardiovascular system. CONCLUSION: We conclude that a ten-minute video game boxing performance induces cardiovascular responses similar to aerobic exercise. This may be a practical form of exercise, but care should be exercised concerning subjects with cardiovascular disorders.

Low-intensity resistance training attenuates dexamethasone-induced atrophy in the flexor hallucis longus muscle

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

A DFT Study of Structural and Electronic Properties of ZnS Polymorphs and its Pressure-Induced Phase Transitions

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Salivary cortisol response to concurrent strength and high-intensity aerobic exercise: a pilot study

Aim. The aim of this pilot study was to compare strength performance and salivary cortisol levels response during a single strength session, and a strength session after 30 min of high-intensity aerobic exercise (concurrent condition).Methods. Saliva was collected from 7 male subjects, before and after all exercise bouts, and the maximum number of repetitions (MNR) and total volume (TV) in the different conditions assessed.Results. The MNR and TV were reduced in concurrent condition compared with control condition. Strength exercise in the concurrent condition induced higher salivary cortisol in relation to strength exercise or to and high-intensity aerobic exercise, separately.Conclusion. The different salivary cortisol profile in response to concurrent exercise reflects the faster reactivity of the hypothalamic-pituitary-adrenocortical system in this circumstance.

Long-term low intensity physical exercise attenuates heart failure development in aging spontaneously hypertensive rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Oxidative dtress status and placental implications in diabetic rats undergoing swimming exercise after embryonic implantation

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

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.