The Effect of rest interval between sets on the number of repetitions performed in the bench press exercise

The aim of the present study was to analyze the effects of different rest intervals on the number of repetitions performed in the bench press exercise. Methods: 6 resistance-trained men (age 24.27±1.61 years, body fat 14.72±5.32 %, body mass 76.60±11.00 kg, 1-RM bench press 98.42±19.78kg) volunteered for the study. Subjects performed a bench press 1-RM test and in two subsequent sessions they performed five maximal sets of the bench press exercise with 70%, 75%, 75%, 80% and 85% of 1-RM and a 1- or 2-minute rest interval between sets. Sessions occurred at least 48h apart, with the last two in a random fashion. Statistical analyzes was made by the student t-test to compare the differences between rest intervals. The number of repetitions performed with the 2-minute rest interval (33.16 ± 6.14) was significantly higher than with 1-minute rest interval (26.67 ± 3.44), (p=0.009) and in sets 2 (p=0.016), 3 (p=0.004) and 4 (p=0.018). The 2-minute rest interval yielded a larger number of repetitions performed throughout the five sets of bench press. Furthermore, the subjects were unable to maintain a large number of repetitions even when a 2-minute rest interval was taken. This indicates that larger rest intervals may be necessary when training with this intensity, especially if the maintenance of exercise volume is desired

Effects of warm-up before stretching on flexibility and torque development in elderly

The purpose of the study was to analyze the effect of warm up exercises on flexibility and torque development of elderly subjects submitted to a protocol of hamstring muscles stretching. 28 subjects (9 men and 19 women), aged 66.4±6 years, volunteered for this study. Subjects were randomly divided into 2 protocols: a stretching protocol (group A) and a warm up and stretching protocol (group B). Both groups received the intervention for 4 weeks, with three sessions per week, consisting of 6 bouts of active stretching lasting 30 seconds. Subjects were evaluated on selection (T1), immediately before the intervention (T2), immediately after (T3) and a month after (T4) the intervention period for measures of knee extension range of motion (ROM) and angle with a goniometer and for active and passive peak torque (Nm s-1) at 60°/s and 2°/s respectively using a isokinetic dynamometer. Anova Two-Way and a post hoc analysis using the Tukey’s test were applied to test the differences between and within groups. Both groups presented reduction of the knee extension range of motion deficit (p=0.001), increase of the active peak torque flexor in eccentric (p=0.003) and concentric (p=0.015) phases, and reduction of the peak torque angle of the knee flexors in the eccentric phase (p=0.046) when comparing T3 with T2 for both groups, without significant difference between groups. The passive peak torque did not vary significantly (p\u3e0.05) between the evaluations. The pre-exercise warm up was unable to elicit differences in flexibility and torque development of the hamstrings in elderly subjects

Influence of upper-body exercise order on hormonal responses in trained men

The aim of this study was to examine acute hormonal responses after different sequences of an upper-body resistance-exercise session. Twenty men completed 2 sessions (3 sets; 70% 1-repetition maximum; 2 min passive rest between sets) of the same exercises in opposite sequences (larger to smaller vs. smaller to larger muscle-group exercises). Total testosterone (TT), free testosterone (FT), testosterone/cortisol (T/C) ratio, sex-hormone-binding globulin (SHBG), growth hormone (GH), and cortisol (C) concentrations were measured before and immediately after each sequence. The results indicate that the GH concentration increased after both sessions, but the increase was significantly greater (p \u3c 0.05) after the sequence in which larger muscle-group exercises were performed prior to the smaller muscle-group exercises. No differences were observed between sessions for TT, FT, SHBG, C, or the T/C ratio at baseline or immediately after resistance exercise. These results indicate that performing larger muscle-group exercises first in an upper-body resistance-exercise session leads to a significantly greater GH response. This may have been due to the significantly greater exercise volume accomplished. In summary, the findings of this investigation support the common prescriptive recommendation to perform larger-muscle group exercises first during a resistance-exercise session

The effects of exercise modalities on adiposity in obese rats

OBJECTIVE: The aim of the present study was to evaluate the effect of both swimming and resistance training on tumor necrosis factor-alpha and interleukin-10 expression, adipocyte area and lipid profiles in rats fed a high-fat diet. METHODS: The study was conducted over an eight-week period on Wistar adult rats, who were divided into six groups as follows (n = 10 per group): sedentary chow diet, sedentary high-fat diet, swimming plus chow diet, swimming plus high-fat diet, resistance training plus chow diet, and resistance training plus high-fat diet. Rats in the resistance training groups climbed a vertical ladder with weights on their tails once every three days. The swimming groups swam for 60 minutes/day, five days/week. RESULTS: The high-fat diet groups had higher body weights, a greater amount of adipose tissue, and higher tumor necrosis factor-alpha expression in the visceral adipose tissue. Furthermore, the high-fat diet promoted a negative change in the lipid profile. In the resistance training high-fat group, the tumor necrosis factor-alpha expression was lower than that in the swimming high-fat and sedentary high-fat groups. Moreover, smaller visceral and retroperitoneal adipocyte areas were found in the resistance training high-fat group than in the sedentary high-fat group. In the swimming high-fat group, the tumor necrosis factor-alpha expression was lower and the epididymal and retroperitoneal adipocyte areas were smaller compared with the sedentary high-fat group. CONCLUSION: The results showed that both exercise modalities improved the lipid profile, adiposity and obesity-associated inflammation in rats, suggesting their use as an alternative to control the deleterious effects of a high-fat diet in humans

Influência de diferentes protocolos de exercício e da dieta hiperlipídica sobre o sistema endocanabinóide de ratos

The objective of the study was to investigate the effects of the hyperlipid diet and the training of swimming and force on the adipose tissue, lipid profi le and endocannabinoid system of exogenous obese rats. For this, we used sixty adult male rats divided into six groups: Sedentary Standard (SP); Sedentary Hyperlipid (SH); Standard Swimming (NP); Hyperlipid Swimming (NH); Standard Force (FP); Hyperlipid Force (FH). After three weeks receiving standard or hyperlipidic diet, the animals started the exercise protocols. The NP and NH groups swam 60 minutes/day, 5 days/week with 5% body weight binding to the body, in 50x30 cm tanks, for 8 weeks. The FP and FH groups performed ladder climbing exercises with weights tied to their tails, once every three days, for 8 weeks. Animals from the SP and SH groups remained sedentary and fed their respective diets. The hyperlipid diet increased body weight gain, relative weight of adipose (epididimal, retroperitoneal, visceral and subcutaneous) and adipocyte (epididimal, retroperitoneal and visceral) areas. It also increased the fat percentage of all adipose tissues and liver, in addition to increasing the gene expression of the CB1 receptor. The trained groups had lower values of adipocyte area, improvement of lipid profi le, lower values in fat percentage of adipose tissues and liver, lower gains of body mass, and lower gene expression of CB1 receptor. Thus our results indicate the potential benefi  ts of strength and swimming training as non-pharma-cological alternatives to control the deleterious effects of the hyperlipidic diet on adipose tissue, lipid profi le, lipid content and control of the imbalance of the endocannabinoid system caused by the hyperlipidic diet.O objetivo do estudo foi investigar os efeitos da dieta hiperlipídica e do treinamento de natação e força sobre o tecido adiposo, perfil lipídico e sistema endocanabinóide de ratos obesos exógenos. Para isso, utilizamos sessenta ratos adultos machos divididos em seis grupos: Sedentário Padrão (SP); Sedentário Hiperlipídico (SH); Natação Padrão (NP); Natação Hiperlipídica (NH); Força Padrão (FP); Força Hiperlipídica (FH). Após três semanas recebendo dieta padrão ou hiperlipídica, os animais iniciaram os protocolos de exercício. Os grupos NP e NH nadaram 60 minutos/dia, 5 dias/semana com carga de 5% do peso corporal atada ao corpo, em tanques de 50x30 cm, durante 8 semanas. Os grupos FP e FH realizaram exercício de subida em escada com pesos atados às suas caudas, uma vez a cada três dias, durante 8 semanas. Os animais dos grupos SP e SH continuaram sedentários e alimentados com suas respectivas dietas. A dieta hiperlipídica aumentou o ganho de massa corporal, peso relativo dos tecidos adiposos (epididimal, retroperitoneal, visceral e subcutâneo) e área de adipócitos (epididimal, retroperitoneal e visceral). Também aumentou o percentual de gordura de todos os tecidos adiposos e fígado, além de aumentar a expressão gênica do receptor CB1. Os grupos treinados apresentaram menores valores de área de adipócitos, melhora do perfil lipídico, menores valores no percentual de gordura dos tecidos adiposos e fígado, menores ganhos de massa corporal, além de menores expressão gênica do receptor CB1. Assim nossos resultados indicam os potenciais benefícios do treinamento força e natação, como alternativas não farmacológicas para controlar os efeitos deletérios da dieta hiperlipídica sobre o tecido adiposo, perfil lipídico, conteúdo lipídico e controle do desequilíbrio do sistema endocanabinóide provocado pela dieta hiperlipídica

Natação e treinamento de força: influências sobre a expressão gênica de TNF-alfa e IL-10, área de adipócitos e perfil lipídico em ratos obesos

The aim of the present study was to investigate the effect of swimming and resistance training exercise on adipose tissue, inflammation and lipid profile in highfat feeding rats. Wistar adult male rats were divided into 6 groups (n = 10 per group): Sed-C, sedentary chow diet; Sed-HL, sedentary high-fat diet; NT-C, swimming chow diet; NT-HL, swimming high-fat diet; TF-C, resistance training chow diet; TF-HL resistance training high-fat diet. An 8-week training period was used. During it period the animals of resistance training groups climbed a 1.1-m vertical ladder with weights attached to their tails. The sessions were performed once every 3 days, with 4 9 climbs and 8 12 dynamic movements per climb. Swimming groups performed 60 min/day, 5 days a week, with a constant overload of 5% body weight during 8 weeks in tanks of 50 cm of height and 30 cm of diameter. High fat-diet increased body weight, relative weight of adipose tissue (epididymal, retroperitoneal, visceral and subcutaneous) and adipose tissue area (epididymal, retroperitoneal and visceral). There was higher TNF-alpha expression and lower (not significant) IL-10 expression in visceral adipose tissue and negative change in lipid profile because of the high-fat diet. Resistance training presented lower values of visceral and retroperitoneal adipocyte area, lower TNF-alpha expression and changed lipid profile. Swimming presented lower epididymal and retroperitoneal adipocyte area, higher IL-10 expression and changed lipid profile. These results indicate the potential benefits of resistance training and swimming as non pharmacological alternatives to control the effects of high-fat diet on adipocyte area, lipid profile and inflammatory process in rats.Universidade Federal de Sao CarlosO objetivo do presente estudo foi investigar os efeitos da natação e do treinamento de força no processo inflamatório, tecido adiposo e perfil lipídico de ratos obesos. Sessenta ratos Wistar adultos (12 semanas) foram divididos em 6 grupos (n = 10 por grupo): Sed-C, dieta padrão sedentário; Sed-HL, dieta hiperlipídica sedentário; NT-C, dieta padrão treinado em natação; NT-HL, dieta hiperlipídica treinado em natação; TF-C, dieta padrão treinado em força; TF-HL, dieta hiperlipídica treinado em força. Foi utilizado um período de treinamento de 8 semanas. Durante este período os animais dos grupos de treinamento de força realizaram escaladas em uma escada de 1,1 m na vertical, com pesos atados às suas caudas. As sessões foram realizadas uma vez a cada três dias, com 4 a 9 escaladas com 8-12 movimentos dinâmicos por escalada. Os grupos de natação realizaram 60 min / dia, cinco dias por semana, com uma carga constante de peso de 5%, em tanques de 50 cm de altura e 30 cm de diâmetro. A dieta hiperlipídica aumentou a massa corporal, peso relativo dos tecidos adiposos (epidídimal, retroperitoneal, visceral e subcutâneo) e a área de adipócitos (epidídimal, retroperitoneal e visceral). Houve maior expressão de TNF-alfa e menor (não significativa) expressão de IL-10 no tecido adiposo visceral e efeitos deletérios no perfil lipídico devido à dieta rica em gordura. Os grupos de treinamento de força apresentaram menores valores de área de adipócitos nos tecidos visceral e retroperitoneal, menor expressão de TNF-alfa e benefícios no perfil lipídico. Os grupos de natação apresentaram menor área de adipócitos nos tecidos epididimal e retroperitoneal, maior expressão de IL-10 e benefícios no perfil lipídico. Estes resultados indicam os potenciais benefícios do treinamento força e da natação, como alternativas não farmacológicas para controlar os efeitos deletérios da dieta benefícios na área de adipócitos, perfil lipídico e processo inflamatório em ratos

Alterações cardiovasculares induzidas pela obesidade : envolvimento do sistema reninaangiotensina no núcleo do trato solitário

In the last decades, obesity has become a worldwide epidemy. Excess of adipose tissue favors the development of associated diseases such as hypertension, obstructive sleep apnea and type II diabetes. Data from the literature have shown that obesity activates the reninangiotensin system (RAS), increases sympathetic nerve activity and pro-inflammatory cytokines levels, including in the central nervous system. However, the pathways and neural mechanisms involved in these responses are not yet fully elucidated. Therefore, the aim of this study was to evaluate the cardiovascular and metabolic responses in high-fat diet (HFD) feeding rats. We also study the possible participation of the RAS and the immune system in the nucleus of the solitary tract (NTS) in the obesity-induced cardiovascular changes. Finally, we tested if the resistance training (RT) performed at moderate intensity would be able to prevent obesityinduced cardiovascular changes. To achieve these goals, adult Holtzman rats (300-320 g) were fed with HFD (3.82 kcal/g and 26.4% total fat) or standard chow diet (SD; 2.25 kcal/g and 5.4% total fat) for 6 weeks. We observed higher blood levels of total cholesterol, triglycerides, leptin and glucose and decreased insulin sensitivity after 6 weeks of HFD. There was an increase in mean arterial pressure (MAP), the sympathetic modulation of systolic blood pressure (SBP), heart rate (HR) and sympathovagal balance of pulse interval (PI), and an impairment in the bradycardic response of the baroreflex in HFD feeding animals. After 6 weeks of HFD, there was an increase in the mRNA expression of the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukine-6 (IL-6), an increase in the mRNA expression of the angiotensin converting enzyme (ACE) and AT1 receptor, and a decrease in the expression of AT2 and Mas receptors. In agreement with the increased expression of cytokines in the NTS we have demonstrated higher GFAP immunoreactivity (specific marker of astrocytes) and higher number of positive cells for Iba-1 (specific marker for microglia) in the NTS in rats fed with HFD. The blockade of AT1 receptor in the NTS in animals fed with HFD promoted a decrease in MAP, reduced the sympathetic modulation in SBP, reduced the sympathovagal balance of PI and restored the bradycardic response of the baroreflex. The overexpression of the AT2 receptors in the NTS in rats fed with HFD reestablished HR, baroreflex sensitivity and sympathovagal balance of PI, and partially attenuated the increase in sympathetic modulation of SBP. These responses were associated with increased Mas receptor mRNA expression and reduction in the TNF-α mRNA expression in the NTS. However, these effects were not sufficient to restore the MAP in HFD feeding rats with AT2 receptors overexpression in the NTS. Finally, the RT prevented cardiovascular changes induced by HFD, including increases in MAP, sympathetic modulation of SBP, HR, sympathovagal balance of PI, and reduced baroreflex sensitivity. These responses were associated with increased expression of mRNA for components of protective RAS axis (AT2 and Mas receptors and ACE2), and the antiinflammatory cytokine IL-10 as well as the reduction of pro-inflammatory cytokines (TNF-α and IL -1β) in the NTS. Together, our data suggest that HFD promotes increases in plasma levels of glucose and leptin, with dysfunction in insulin sensitivity. HFD also promotes increases in blood pressure associated with increased sympathetic modulation in SBP, sympathovagal balance of PI, HR and baroreflex dysfunction. The neuroinflammatory process and an imbalance between the pressor and protective RAS axis in the NTS seem to be involved with the development/maintenance of the cardiovascular alterations induced by HFD. The TF performed at moderate intensity seems to be an important tool in preventing cardiovascular changes induced by HFD.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Nas últimas décadas a obesidade se tornou uma epidemia mundial. O excesso de tecido adiposo favorece o desenvolvimento de doenças associadas como a hipertensão arterial, apnéia obstrutiva do sono e diabetes tipo II. Dados da literatura mostram que a obesidade ativa o sistema renina-angiotensina (SRA), e aumenta a atividade do sistema nervoso simpáticoe os níveis de citocinas pró-inflamatórias, inclusive no sistema nervoso central. Entretanto, as vias e mecanismos neurais envolvidos nessas respostas ainda não estão completamente elucidados. Portanto, o objetivo do presente estudo foi avaliar as respostas cardiovasculares e metabólicas em ratos alimentados com dieta hiperlipídica (DH). Estudamos também a possível participação do SRA e do sistema imune no núcleo do trato solitário (NTS) nas alterações cardiovasculares induzidas pela DH. Por fim, testamos se o treinamento de força (TF) realizado em intensidade moderada seria capaz de prevenir as alterações cardiovasculares induzidas pela DH. Para tanto, foram utilizados ratos Holtzman adultos (300 a 320 g) alimentados com DH (3,82 kcal/g e 26,4% de gorduras) ou dieta padrão (DP; 2,25 kcal/g e 5,4% de gorduras) por 6 semanas. Nossos resultados demonstraram maiores níveis de colesterol total, triacilgliceróis, leptina e glicose no sangue e menor sensibilidade à insulina após 6 semanas de DH. Houve um aumento da pressão arterial média (PAM), da modulação simpática da pressão arterial sistólica (PAS), da frequência cardíaca (FC) e do balanço simpatovagal do intervalo de pulso (IP) e menor resposta bradicárdica do barorreflexo em animais alimentados com DH. Após 6 semanas de DH, houve maior expressão do RNAm das citocinas pró-inflamatórias, fator de necrose tumoral-α (TNF- α) e interleucina-6 (IL-6), maior expressão do receptor AT1 e da enzima conversora de angiotensina (ECA) e menor expressão dos receptores AT2 e Mas. Corroborando com a maior expressão de citocinas no NTS, foi demonstrado maior imunoreatividade para GFAP (marcador especifico de astrócitos) e maior número de células positivas para Iba-1 (marcador especifico para micróglias) no NTS de ratos alimentados com DH. O bloqueio do receptor AT1 no NTS de animais alimentados com DH promoveu queda na PAM, reduziu a modulação simpática na PAS, reduziu o balanço simpatovagal do IP e restabeleceu a resposta de bradicardia reflexa. A super-expressão de receptores AT2 no NTS de ratos alimentados com DH reestabeleceu a FC, a sensibilidade do barorreflexo e o balanço simpatovagal do IP, além de uma atenuação parcial na modulação simpática da PAS. Essas respostas foram associadas com o aumento da expressão do RNAm do receptor Mas e a redução na expressão do TNF-α no NTS. Porém, esses efeitos não foram suficientes para atenuar a PAM nos ratos com DH e super-expressão de receptores AT2 no NTS. Por fim, o TF preveniu as alterações cardiovasculares induzidas pela DH, incluindo o aumento da PAM, da modulação simpática da PAS, da FC, do balanço simpatovagal do IP, e a redução da sensibilidade do barorreflexo. Essas respostas foram associadas com um aumento na expressão do RNAm de componentes da via protetora do SRA (receptores AT2 e Mas e ECA2) e da citocina anti-inflamatória IL-10, bem como a redução de citocinas próinflamatórias (TNF-α e IL-1β) no NTS. Em conjunto, nossos dados sugerem que a DH promove aumentos na leptina plasmática e na glicemia, com disfunção na sensibilidade à insulina e no perfil lipídico. A DH também promove aumento na pressão arterial associada aos aumentos na modulação simpática na PAS, balanço simpatovagal do IP, FC e disfunção no barorreflexo. O processo neuroinflamatório e um desequilíbrio entre as vias pressora e protetora do SRA no NTS parecem estar envolvidos com o desenvolvimento/manutenção das alterações cardiovasculares encontradas em ratos alimentados com DH. O TF realizado em intensidade moderada parece ser uma importante ferramenta na prevenção das alterações cardiovasculares induzidas pela DH.2013/13118-

Prevalência e fatores associados para sobrepeso e obesidade em alunos de uma escola privada de São Paulo

A obesidade tem crescido de forma significativa nos últimos anos, tornando-se assim um grave problema de saúde pública principalmente pelo fato do excesso de tecido adiposo aumentar o risco de desenvolvimento de diversas doenças crônico-degenerativas associadas. O objetivo do presente estudo foi verificar a prevalência sobrepeso e obesidade em 134 crianças matriculadas em uma escola particular de São Paulo-SP, sendo 72 do gênero masculino e 62 do gênero feminino de 06 a 10 anos. Para a coleta de tais dados foram utilizados o Índice de Massa Corporal (IMC), questionário sobre o nível de atividades e exercícios físicos feitos pela criança, além do nível de alimentação da mesma dentro do âmbito escolar. A prevalência de sobrepesos e obesidade foi de 41,8% nas meninas, 42,9% nos meninos e 42,5% para a amostra total. Esses resultados sugerem que os valores de sobrepeso e obesidade entre escolares de São Paulo-SP foram significativos, e sua prevalência é maior nos indivíduos do gênero masculino. As implicações que os resultados nos mostram estão relacionadas com a pouca prática de atividades e exercícios físicos, o tempo gasto com aparelhos eletrônicos e uma alimentação inadequada, com uma grande frequência em restaurantes Fast Foods. Como medidas de intervenção e prevenção da obesidade na infância, entra em cena a escola e a família tendo um papel muito importante no esclarecimento e orientação das crianças para uma vida mais ativa incentivando a prática de atividades e exercícios físicos e uma alimentação adequada. Para que os resultados sejam mais eficazes é necessário ter uma equipe multidisciplinar composta por educadores físicos, nutricionistas, médicos, psicólogos, etc. ABSTRACTPrevalence and associated factors for overweight and obesity in students of a private school in São PauloObesity has grown significantly in recent years, thus becoming a serious public health problem mainly because of excess fat increase the risk of developing several chronic degenerative diseases associated. The aim of this study was to investigate the prevalence of overweight and obesity in 134 children attending a private school in São Paulo - SP, 72 males and 62 females 06-10 years. To collect such data Index Body Mass (BMI) questionnaire Activity Level and exercise made by child beyond level Feed Same inside University activities were used. The prevalence of overweight and obesity was 41.8 % for girls, 42.9 % for boys and 42.5 % for the total sample. These results suggest that the values of overweight and obesity among schoolchildren in São Paulo - SP were significant, and its prevalence is higher in male subjects. The implications that the results show us relate to the poor practice of physical activities and exercises, spending time with electronics and an inadequate diet, with a high frequency in restaurants fast foods. As intervention and prevention of obesity in childhood, enters the scene and school has a very important role in clarifying and guiding children to a more active life by encouraging the practice of physical activities and exercises and proper nutrition. For the results to be most effective you must have a multidisciplinary team consisting of physical educators, nutritionists, physicians, psychologists, etc