Influência do índice glicêmico da refeição pré-exercício sobre a glicemia e parâmetros cardiometabólicos durante exercício aeróbico matinal

• Autor(a) principal: Faria, Valéria Cristina de
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/3485
• topic: Nutrição esportiva; Índice glicêmico; Bebida carboidratada; Exercício aeróbico; Sports nutrition; Glycemic index; Carbohydrate beverage; Aerobic Exercise; CNPQ::CIENCIAS DA SAUDE::EDUCACAO FISICA

The literature states that a feed conducted with a three hour prior to exercise is suitable for powering an adequate gastric emptying and maintain during the same normoglycemic (Ribeiro et al., 2005) and 2 hours (Chen et al. 2,009 ; Wong et al. 2009). But for practice this morning physical conduct does not reflect reality, since the previous time becomes restricted, which may lead the practitioner to exercise fasting or eating very close to the activity, being in both situations subject to a framework hypoglycemia. The aim of this thesis was to monitor and evaluate the glycemic response 30 minutes before and during an activity cycle ergometer with 1 hour, after three procedures nutritional "breakfast": a) a high glycemic index, b) low glycemic index; c) in the fasting state, administering two kinds of hydration: water and carbohydrate drink with a concentration of 60 g/L. The specific objectives were to monitor and evaluate the behavior of blood gases before and during exercise, establish correlations of thesewith possible changes cardiorespiratory parameters, assess substrate oxidation during exercise, analyze hematocrit, hemoglobin, calcium, sodium, potassium, lactate and evaluate the water balance. The first study was conducted in a query PubMed database using the keywords: aerobic exercise, glicemic and glycemia index, combined. Were adopted as inclusion criteria, original articles, published in English in the last five years and performed with humans, and as exclusion criteria, sample unhealthy and exercise withoutpredominance aerobic. We selected 11 articles, which varied by gender of the sample and its conditioning, the type of exercise selected, as well as its duration and intensity, the value of IG adopted, and the time prior to food intake from 15 minutes to three hours. According to the results, low glycemic foods cause lower postprandial glycemic alterations which may result in a more stable throughout the year, making it a more conservative nutritional strategy for the general population, it should also be noted that a meal provided between 15 and 45 minutes before the start of the year may not be the most suitable, due to peak insulin action usually occurs during this period, which together with the effects of muscle contraction could trigger a framework of hypoglycemia rebound. None of the studies listed in this review addressed prior time. In the second study twelve men healthy and physically active performed four experimental tests, two with pre-exercise meals, high GI (AIG) and low GI (BIG), and two were conducted in the fasting state differentiated by hydration, water (H2O) and carbohydrate drink (CHO). Each test consisted of a rest period prior to exercise for 30 minutes, followed by 60 minutes of cycle ergometer with continuous load equivalent to 60% of maximal oxygen uptake extrapolated (VO2MaxExt). During exercise participants were hydrated every 15 minutes, and 3mL per kg bodyweight. There was no difference in substrate oxidation, there was a lower postprandial glycemic alterations caused by BIG meal, although not significant, and a high potassium levels at year-end after the BIG meal, being significant in relation to CHO fasting. In addition, there was a maintenance of blood glucose levels stable and higher during exercise in relation to other procedure in fasting CHO. In the third study was carried collection of blood samples for analysis of lactate, pH, PCO2, PO2, TCO2, HCO3, BE and SO2 fasting, immediately before consumption of the "breakfast", like 15 and 30 minutes after consumption .During the exercise, samples were collected at intervals of 20 minutes until the end of 60 minutes of exercise, as well as the cardiorespiratory parameters. The results showed that the four experimental procedures were able to maintain cardiorespiratory parameters and arterial blood gases of the participants, which was probably due to the maintenance of hydration status. Thus, given the evidence cited in the first study that BIG foods cause less postprandial glycemic change, this seems to be a more conservative nutritional strategy for the general population. This fact was confirmed in the second job and the third reinforced therefore independent of nutritional procedure adopted in conjunction with a hydration of 3 mL/kg of body weight every 15 minutes, no changes in cardiorespiratory parameters and blood gases. Furthermore, when performed on fasting, hydration with carbohydrate drink hypoglycemic seems to minimize the risk arising that state.