1,641 research outputs found

    Short And Long Term Effects Of High-intensity Interval Training On Hormones, Metabolites, Antioxidant System, Glycogen Concentration, And Aerobic Performance Adaptations In Rats

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The purpose of the study was to investigate the effects of short and long term High-Intensity Interval Training (HIIT) on anaerobic and aerobic performance, creatinine, uric acid, urea, creatine kinase, lactate dehydrogenase, catalase, superoxide dismutase, testosterone, corticosterone, and glycogen concentration (liver, soleus, and gastrocnemius). The Wistar rats were separated in two groups: HIIT and sedentary/control (CT). The lactate minimum (LM) was used to evaluate the aerobic and anaerobic performance (AP) (Baseline, 6, and 12 weeks). The lactate peak determination consisted of two swim bouts at 13% of body weight (bw): (1) 30 s of effort; (2) 30 s of passive recovery; (3) exercise until exhaustion (AP). Tethered loads equivalent to 3.5, 4.0, 4.5, 5.0, 5.5, and 6.5% bw were performed in incremental phase. The aerobic capacity in HIIT group increased after 12 weeks (5.2 +/- 0.2% bw) in relation to Baseline (4.4 +/- 0.2% low), but not after 6 weeks (4.5 +/- 0.3% bw). The exhaustion time in HIIT group showed higher values than CT after 6 (HIIT = 58 +/- 5 s; CT = 40 +/- 7 s) and 12 weeks (HIIT = 62 +/- 7 s; CT = 49 +/- 3 s). Glycogen (mg/100 mg) increased in gastrocnemius for HIIT group after 6 weeks (0.757 +/- 0.076) and 12 weeks (1.014 +/- 0.157) in comparison to Baseline (0.358 +/- 0.024). In soleus, the HIIT increased glycogen after 6 weeks (0.738 +/- 0.057) and 12 weeks (0.709 +/- 0.085) in comparison to Baseline (0.417 +/- 0.035). The glycogen in liver increased after HIIT 12 weeks (4.079 +/- 0.319) in relation to Baseline (2.400 +/- 0.416). The corticosterone (ng/mL) in HIIT increased after 6 weeks (529.0 +/- 30.5) and reduced after 12 weeks (153.6 +/- 14.5) in comparison to Baseline (370.0 +/- 18.3). In conclusion, long term HIIT enhanced the aerobic capacity, but short term was not enough to cause aerobic adaptations. The anaerobic performance increased in HIIT short and long term compared with CT, without differences between HIIT short and long term. Furthermore, the glycogen super-compensation increased after short and long term HIIT in comparison to Baseline and CT group. The corticosterone increased after 6 weeks, but reduces after 12 weeks. No significant alterations were observed in urea, uric acid, testosterone, catalase, superoxide dismutase, sulfhydryl groups, and creatine kinase in HIIT group in relation to Baseline and CT.7FAPESP [04/01205-6, 06/58411-2]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Short and long term effects of high-intensity interval training on hormones, metabolites, antioxidant system, glycogen concentration, and aerobic performance adaptations in rats

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    The purpose of the study was to investigate the effects of short and long term High-Intensity Interval Training (HIIT) on anaerobic and aerobic performance, creatinine, uric acid, urea, creatine kinase, lactate dehydrogenase, catalase, superoxide dismutase, testosterone, corticosterone, and glycogen concentration (liver, soleus, and gastrocnemius). The Wistar rats were separated in two groups: HIIT and sedentary/control (CT). The lactate minimum (LM) was used to evaluate the aerobic and anaerobic performance (AP) (Baseline, 6, and 12 weeks). The lactate peak determination consisted of two swim bouts at 13% of body weight (bw): (1) 30 s of effort; (2) 30 s of passive recovery; (3) exercise until exhaustion (AP). Tethered loads equivalent to 3.5, 4.0, 4.5, 5.0, 5.5, and 6.5% bw were performed in incremental phase. The aerobic capacity in HIIT group increased after 12 weeks (5.2 +/- 0.2% bw) in relation to Baseline (4.4 +/- 0.2% low), but not after 6 weeks (4.5 +/- 0.3% bw). The exhaustion time in HIIT group showed higher values than CT after 6 (HIIT = 58 +/- 5 s; CT = 40 +/- 7 s) and 12 weeks (HIIT = 62 +/- 7 s; CT = 49 +/- 3 s). Glycogen (mg/100 mg) increased in gastrocnemius for HIIT group after 6 weeks (0.757 +/- 0.076) and 12 weeks (1.014 +/- 0.157) in comparison to Baseline (0.358 +/- 0.024). In soleus, the HIIT increased glycogen after 6 weeks (0.738 +/- 0.057) and 12 weeks (0.709 +/- 0.085) in comparison to Baseline (0.417 +/- 0.035). The glycogen in liver increased after HIIT 12 weeks (4.079 +/- 0.319) in relation to Baseline (2.400 +/- 0.416). The corticosterone (ng/mL) in HIIT increased after 6 weeks (529.0 +/- 30.5) and reduced after 12 weeks (153.6 +/- 14.5) in comparison to Baseline (370.0 +/- 18.3). In conclusion, long term HIIT enhanced the aerobic capacity, but short term was not enough to cause aerobic adaptations. The anaerobic performance increased in HIIT short and long term compared with CT, without differences between HIIT short and long term. Furthermore, the glycogen super-compensation increased after short and long term HIIT in comparison to Baseline and CT group. The corticosterone increased after 6 weeks, but reduces after 12 weeks. No significant alterations were observed in urea, uric acid, testosterone, catalase, superoxide dismutase, sulfhydryl groups, and creatine kinase in HIIT group in relation to Baseline and CT7FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP04/01205-6; 06/58411-

    Metabolic responses to acute physical exercise in young rats recovered from fetal protein malnutrition with a fructose-rich diet

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    <p>Abstract</p> <p>Background</p> <p>Malnutrition <it>in utero </it>can "program" the fetal tissues, making them more vulnerable to metabolic disturbances. Also there is association between excessive consumption of fructose and the development of metabolic syndrome. However, there is little information regarding the acute effect of physical exercise on subjects recovered from malnutrition and/or fed with a fructose-rich diet. The objective of this study was to evaluate the metabolic aspects and the response to acute physical exercise in rats recovered from fetal protein malnutrition with a fructose-rich diet.</p> <p>Methods</p> <p>Pregnant Wistar rats were fed with a balanced (B) diet or a low-protein (L) diet. After birth and until 60 days of age, the offspring were distributed into four groups according to the diet received: B: B diet during the whole experiment; balanced/fructose (BF): B diet until birth and fructose-rich (F) diet afterwards; low protein/balanced (LB): L diet until birth and B diet afterwards; low protein/fructose (LF): L diet until birth and F diet afterwards.</p> <p>Results</p> <p>The excess fructose intake reduced the body weight gain, especially in the BF group. Furthermore, the serum total cholesterol and the LDL cholesterol were elevated in this group. In the LF group, the serum total cholesterol and the muscle glycogen increased. Acute physical exercise increased the serum concentrations of glucose, triglycerides, HDL cholesterol and liver lipids and reduced the concentrations of muscle glycogen in all groups.</p> <p>Conclusion</p> <p>An excess fructose intake induced some signs of metabolic syndrome. However, protein malnutrition appeared to protect against the short term effects of fructose. In other hand, most responses to acute physical exercise were not influenced by early malnutrition and/or by the fructose overload.</p

    Forced Swim Reliability for Exercise Testing in Rats by a Tethered Swimming Apparatus

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    To assess the physical capacity of rats in forced swim tests, the animal should perform a continuous activity (CON) at the surface to avoid apnea. Bobbing movement (BOB), vigorous paddling known as climbing (CLI), and diving activity (DIV) are inadequate swimming patterns known to increase the exercise intensity variability, impairing the test reliability. Thus, the exercise work accomplished and related physiological variables, such as the blood lactate concentration, may be unreproducible in forced swim. This study aimed to verify the exercise work reproducibility in rats with a 30-min test–retest at maximal lactate steady state (MLSS) intensity using a tethered-swimming apparatus that analyzes swimming patterns by the direct measurement of swimming force. Additionally, it was determined the swimming force and duration of CON, BOB, CLI, and DIV at physiologically different exercise-intensities. The swimming force at MLSS (n = 64) was 38 ± 7 gf.Kg-1, while the blood lactate concentration was 4.2 ± 1.6 mmol.L-1. In the test–retest (N = 23), swimming force (36.6 ± 7 gf.Kg-1 vs. 36.4 ± 7 gf.Kg-1) and blood lactate concentration (4.7 ± 1.7 mmol.L-1 vs. 4.2 ± 1.7 mmol.l-1) were similar, but only the swimming force was highly correlated (0.90 and 0.31). Although it was not statistically different, the swimming force for CON tends to be slightly lower than CLI and slightly higher than BOB independently of exercise-intensity. The CON pattern predominates (∼52.8 ± 18%) at intensities below and of MLSS but BOB was the swimming pattern more often observed above MLSS-intensity (52.6 ± 18%). The present study used a tethered swimming apparatus to investigate the reliability of forced swim tests for exercise testing in rats and better understand the swimming patterns when determining the MLSS, but the results can be extended to any study that rely on forced swim for exercise testing and training. The result suggests that, at least at intensities of physiological stability, the exercise work accomplished by rats is reproducible in forced swim, but the blood lactate concentration seems to be affected by other factors, such as the apnea and stress caused by the possibility of drowning, besides the exercise-intensity

    Interaction between Advanced Glycation End Products Formation and Vascular Responses in Femoral and Coronary Arteries from Exercised Diabetic Rats

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    Background: The majority of studies have investigated the effect of exercise training (TR) on vascular responses in diabetic animals (DB), but none evaluated nitric oxide (NO) and advanced glycation end products (AGEs) formation associated with oxidant and antioxidant activities in femoral and coronary arteries from trained diabetic rats. Our hypothesis was that 8-week TR would alter AGEs levels in type 1 diabetic rats ameliorating vascular responsiveness. Methodology/Principal Findings: Male Wistar rats were divided into control sedentary (C/SD), sedentary diabetic (SD/DB), and trained diabetic (TR/DB). DB was induced by streptozotocin (i.p.: 60 mg/kg). TR was performed for 60 min per day, 5 days/week, during 8 weeks. Concentration-response curves to acetylcholine (ACh), sodium nitroprusside (SNP), phenylephrine (PHE) and tromboxane analog (U46619) were obtained. The protein expressions of eNOS, receptor for AGEs (RAGE), Cu/Zn-SOD and Mn-SOD were analyzed. Tissues NO production and reactive oxygen species (ROS) generation were evaluated. Plasma nitrate/nitrite (NOx-), superoxide dismutase (SOD), catalase (CAT), thiobarbituric acid reactive substances (TBARS) and N-epsilon-(carboxymethyl) lysine (CML, AGE biomarker). A rightward shift in the concentration-response curves to ACh was observed in femoral and coronary arteries from SD/DB that was accompanied by an increase in TBARS and CML levels. Decreased in the eNOS expression, tissues NO production and NOx- levels were associated with increased ROS generation. A positive interaction between the beneficial effect of TR on the relaxing responses to ACh and the reduction in TBARS and CML levels were observed without changing in antioxidant activities. The eNOS protein expression, tissues NO production and ROS generation were fully re-established in TR/DB, but plasma NOx- levels were partially restored. Conclusion: Shear stress induced by TR fully restores the eNOS/NO pathway in both preparations from non-treated diabetic rats, however, a massive production of AGEs still affecting relaxing responses possibly involving other endothelium-dependent vasodilator agents, mainly in coronary artery.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo-FAPESPFundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP

    Desenvolvimento de um modelo para avaliar o nível de manutenção Lean de uma organização : caso de estudo

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    Trabalho final de mestrado para obtenção do grau de mestre em Engenharia MecânicaA criação de um modelo de avaliação Lean é importante para criar boas práticas a aplicar na área da manutenção, como principio de uma atividade que utiliza ferramentas Lean e consciente de todas as suas vantagens. A implementação de filosofia Lean na manutenção visa melhorar o planeamento e a programação das atividades, aumentar a produtividade, motivar os trabalhadores, ajudar na introdução de novos hábitos e de novas atitudes no trabalho e ainda identificar os desperdícios que devem ser eliminados. A competitividade e o preço excessivo dos produtos (bens ou serviços) que o cliente final não quer pagar, faz com que as empresas públicas e privadas tomem medidas para evitar todo o tipo de desperdícios, rentabilizando ao máximo a sua cadeia de valor. A filosofia Lean foi uma das formas encontradas para identificar e eliminar alguns desses desperdícios, melhorando o processo produtivo e, desta forma, tornando as organizações mais competitivas. O Lean tem várias ferramentas podendo ser aplicadas em diversas áreas. Uma dessas áreas é a manutenção, onde se pretende que os equipamentos operem sem interrupções e com uma produção de qualidade. Algumas das ferramentas do Lean encaixam-se perfeitamente na área da manutenção para identificação de desperdícios, criação de valor, realização de planeamento, melhoria do sistema de trabalho na organização e até no próprio desenvolvimento dos trabalhadores. A presente dissertação visa mostrar algumas das ferramentas mais comuns da filosofia Lean com aplicabilidade na manutenção de equipamentos de apoio à atividade de um serviço publico e ao desenvolvimento de um modelo de avaliação com apresentação através de estudo de caso. No trabalho infra são apresentadas diversas ferramentas Lean, nomeadamente 5s, trabalho padronizado, (standardwork uniformização), gestão visual (andon), melhoria continua (kaisen), mapeamento fluxo de valor na manutenção (MVSM), SIPOC, gestão visual, 5w, ciclo PDCA. O modelo de avaliação está estruturado em 3 grandes áreas “Clientes”, “Organização” e “Fornecedores”, vai subdividir-se em 7 critérios e 60 atributos. Dos 60 atributos, foram desenvolvidos 6 e que compõem mais de 70 atributos, perfazendo mais de 130 no final o modelo proposto neste trabalho.The creation of a lean evaluation model is important to create good practice in the field of maintenance as the principle of an activity that uses lean tools aware of all its advantages. Implementing Lean's philosophy of maintenance aims to improve planning and scheduling of activities, increase productivity, motivate employees, assist in introducing new habits and new attitudes at work, and identify the wastes that need to be eliminated. Competitiveness and the excessive price of products (goods or services) that the final customer does not want to pay, makes public and private companies take measures to avoid all types of waste, making the most of its value chain. The Lean philosophy was one of the ways found to identify and eliminate some of these wastes, improving the production process and thus making companies more competitive. Lean has several tools that can be applied in several areas. One of these areas is maintenance, where the equipment is intended to operate without interruption and with a quality production. Some of Lean's tools fit perfectly into the maintenance area for waste identification, value creation. The present dissertation aims to show some of the most common tools of the Lean philosophy with applicability in the maintenance of equipment to support the activity of a public service and the development of an evaluation model with presentation through case study. In the work below are presented several Lean tools, namely 5s, standardized work, (standardwork standardization), visual management (andon), continuous improvement (kaisen), maintenance value flow mapping (MVSM), SIPOC, visual management, 5w, cycle PDCA. The avaliation model is structured in 3 large areas "Customers", "Organization" and "Suppliers", will be subdivided into 7 criteria and 60 attributes. Of the 60 attributes were developed 6 and that make up more than 70 attribute attributes, preferring more than 130 at the end the model proposeN/
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