Efeito da auto liberação miofascial na flexibilidade de escolares: uma proposta acessível / Effects of self myofascial release on the flexibility of students: an accessible proposal

RESUMO Diversas pesquisas têm avaliado a aplicabilidade da técnica de auto liberação miofascial (ALM) na melhora aguda da flexibilidade em inúmeros esportes e/ou populações diferentes. No entanto, torna-se difícil sua inserção nas aulas de educação física escolar pelo elevado custo dos materiais. Dessa forma, buscou-se investigar o efeito da ALM em escolares por meio da utilização de rolos de espumas originais e com rolos confeccionados com materiais adaptados de baixo custo. Participaram da pesquisa 30 escolares, que foram aleatoriamente agrupados em: Grupo Controle (GCT), Grupo Rolo Original (GRO) e Grupo Rolo Adaptado (GRA). A flexibilidade foi avaliada antes e após a aplicação da ALM. A ALM foi realizada em músculos alvos uma vez por 30 segundos com intervalos de 15 segundos entre os estímulos. As comparações na flexibilidade pré e pós ALM foram avaliadas utilizando o teste de t student, com nível de significância adotado de p<0,05. Verificou-se que a ALM no GRO e GRA aumentaram agudamente a flexibilidade dos escolares em 7,53 e 16,5%, respectivamente. Assim, a utilização de rolos confeccionados com material alternativo (adaptado) para aplicação da ALM se mostra uma forma mais acessível financeiramente para ser utilizada nas aulas de educação física e abre possibilidades para sua aplicação para além das escolas.

ABSTRACT Several studies have assessed the applicability of the Myofascial Self-Release Technique (MSRT) in the acute improvement of flexibility in various sports and/or different populations. However, its integration into school physical education classes becomes challenging due to the high cost of materials. Therefore, the aim was to investigate the effect of MSRT on schoolchildren using both original foam rollers and rollers made from low-cost adapted materials. Thirty schoolchildren participated in the study and were randomly grouped into: Control Group (CG), Original Roller Group (ORG), and Adapted Roller Group (ARG). Flexibility was evaluated before and after the application of MSRT. MSRT was performed on target muscles once for 30 seconds with intervals of 15 seconds between stimuli. Comparisons in pre- and post-MSRT flexibility were assessed using the Student's t-test, with a significance level adopted of p <0.05. It was found that MSRT in ORG and ARG significantly increased schoolchildren's flexibility by 7.53% and 16.5%, respectively. Therefore, the use of rollers made with alternative (adapted) material for applying MSRT appears to be a more financially accessible way to be used in physical education classes and opens possibilities for its application beyond schools.

Cardiac sympathetic drive is increased in cafeteria diet-fed rats independent of impairment in peripheral baroreflex and chemoreflex functions.

BACKGROUND AND AIMS: Consumption of a high caloric diet induces autonomic imbalance, which can lead to cardiovascular disease. Impaired arterial baroreflex control is suggested to play an important role in cardiovascular autonomic imbalance, often seen in obesity. We previously demonstrated that cafeteria diets increase the sympathetic drive to white and brown adipose tissue. METHODS AND RESULTS: After feeding a cafeteria diet to rats for 26 days, we evaluated: (i)heart rate (HR) and arterial pressure (AP); (ii)baroreflex and chemoreflex function; and (iii) autonomic modulation of the heart and vessels, measured through pulse interval (PI) and systolic arterial pressure (SAP) variability analyses and following administration of autonomic blockers. The cafeteria diet increased body fat mass and serum insulin, leptin, triacylglycerol and cholesterol levels. Baseline HR (15%) was also increased, accompanied by increased power in the low frequency band (60%) and in the low frequency/high frequency ratio (104%) in the PI spectra. Nonlinear analysis revealed an increased occurrence of 0V (39%) and decreased occurrence of 2UV (18%) patterns. Following administration of autonomic blockers, we observed an increase in cardiac sympathetic tone (425%) in cafeteria diet-fed rats. The cafeteria diet had no effect on AP, SAP variability, baroreflex and chemoreflex control. CONCLUSION: Our findings suggest that consumption of a cafeteria diet increases sympathetic drive to the heart but not to the blood vessels, independent of impairment in baroreflex and chemoreflex functions. Other mechanisms may be involved in the increased cardiac sympathetic drive, and compensatory vascular mechanisms may prevent the development of hypertension in this model of obesity.

Identification of Suitable Reference Genes for Quantitative Gene Expression Analysis in Innervated and Denervated Adipose Tissue from Cafeteria Diet-Fed Rats.

Our previous studies show that cafeteria diet increases body adiposity, plasma insulin levels, and sympathetic activity to brown adipose tissue (BAT) and white adipose tissue (WAT) of Wistar rats, leading to rapid and progressive changes in the metabolic profile. The identification of suitable reference genes that are not affected by the experimental conditions is a critical step in accurate normalization of the reverse transcription quantitative real-time PCR (qRT-PCR), a commonly used assay to elucidate changes in the gene expression profile. In the present study, the effects of the cafeteria diet and sympathetic innervation on the gene expression of adrenoceptor beta 3 (Adrb3) from BAT and WAT were assessed using one of the most stable and one of the least stable genes as normalizers. Rats were fed the cafeteria diet and on the 17th day, interscapular BAT or retroperitoneal WAT was denervated and, 7 days after surgery, the contralateral innervated tissue was used as control. Ten reference genes were evaluated (18S, B2m, Actb, CypA, Gapdh, Hprt1, Rpl32, Tbp, Ubc, and Ywhaz) and ranked according to their stability using the following algorithms: geNorm, NormFinder, BestKeeper, and comparative delta threshold cycle (ΔC t ) method. According to the algorithms employed, the normalization of Adrb3 expression by the least stable genes produced opposite results compared with the most stable genes and literature data. In cafeteria and control diet-fed rats, the three most stable genes were Hprt1, Tbp, and Rpl32 for interscapular BAT and Tbp, B2m, and Hprt1 for retroperitoneal WAT, while the least stable genes were 18S, Actb, and Gapdh for both tissues.

Insulin as a hormone regulator of the synthesis and release of leptin by white adipose tissue.

Leptin and its receptor are widely distributed in several tissues, mainly in white adipose tissue. The serum leptin is highly correlated with body mass index in rodents and humans, being documented that leptin levels reduces in the fasting state and increase during refeeding, similarly to insulin release by pancreatic islets. Insulin appears to increase leptin mRNA and protein expression and its release by adipocytes. Some studies have suggested that insulin acts through the activation of the transcription factors: sterol regulatory element binding protein 1 (SREBP1), CCAAT enhancer binding protein-α (C/EBP-α) and specificity protein 1 (Sp1). Insulin stimulates the release of preformed and newly synthesized leptin by adipocytes through its signaling cascade. Its effects are blocked by inhibitors of the insulin signaling pathway, as well as by inhibitors of protein synthesis and agents that increase the intracellular cAMP. The literature data suggest that chronic hyperinsulinemia increases serum leptin levels in humans and rodents. In this review, we summarized the most updated knowledge on the effects of insulin on serum leptin levels, presenting the cell mechanisms that control leptin synthesis and release by the white adipose tissue.

Role of calcitonin gene-related peptide in energy metabolism.

PURPOSE: Calcitonin gene-related peptide (CGRP) is a neuropeptide produced by alternative tissue-specific splicing of the primary transcript of the CALC genes. CGRP is widely distributed in the central and peripheral nervous system, as well as in several organs and tissues. The presence of CGRP in the liver and brown and white adipose tissue suggests an effect of this neuropeptide on regulation of energy homeostasis. METHODS: In this review, we summarize the current knowledge of the effect of CGRP on the control of energy metabolism, primarily focusing on food intake, thermoregulation and lipid metabolism in adipose tissue, liver and muscle. RESULTS: CGRP induces anorexia, stimulating anorexigenic neuropeptide and/or inhibiting orexigenic neuropeptide expression, through cAMP/PKA pathway activation. CGRP also induces energy expenditure, increasing the skin temperature and brown adipose tissue thermogenesis. It has been also suggested that information related to peripheral lipid stores may be conveyed to the brain via CGRP-sensory innervation from adipose tissue. More recently, it was demonstrated that mice lacking αCGRP are protected from obesity induced by high-fat diet and that CGRP regulates the content of lipid in liver, muscle and adipose tissue. CONCLUSIONS: It is unclear the receptor responsible by CGRP effects, as well as whether this neuropeptide acts directly or indirectly in liver, muscle and adipose tissue.