Efeito da ingestão de bebidas energéticas com e sem carboidratos sobre o desempenho físico

• Autor(a) principal: Pereira, Juscélia Cristina
• 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/123456789/3504
• topic: Aptidão física; Bebidas energéticas; Cafeína - Efeito fisiológico; Cafeína; Aptidão física - Testes; Physical fitness; Energy drinks; Caffeine - Physiological effect; Caffeine; Physical fitness - Tests; CNPQ::CIENCIAS DA SAUDE::EDUCACAO FISICA

This dissertation consists of two articles and two chapters. The first article ever published in the Revista Andaluza de Medicina del Deporte aimed to describe, through literature review, the effects of taurine (Tau) on aerobic and anaerobic physical performance as well as its mechanisms of action.A systematic literature review on PubMed/Medline and SPORTDiscus was performed, including studies on humans which were published in English between January 1 st , 2000 and September 1 st , 2011.The forms of Tau intake were as the isolated compound (Tau) or as an ingredient in energy drinks analyzed with a placebo supplement. Significant improvements were observed in aerobic activities and in anaerobic activities after intake of Tau, compared to the placebo. The main ergogenic effect observed in the aerobic component was an increase on the temporal capacity of performing an exercise, whereas for the anaerobic activity there was a better response of calcium ions during muscle contraction. The consumption of only 1 g of Tau, regardless of the time prior to intake, showed a beneficial effect on aerobic and anaerobic physical performance.The second article submitted to Brazilian Journal of Sports Medicine, investigated the potential ergogenic effects of energy drinks on aerobic and anaerobic exercise performance and their mechanisms of action. We performed a systematic review of the literature in PubMed/Medline and SportDiscus, with the inclusion criteria of human studies, and published in English or Spanish between January 1 st , 2000 and April 1 st , 2012. Regarding articles about consequences of energy drinks in aerobic exercise, there were significant improvements in total exercise time, cardiorespiratory capacity and rate of perceived exertion. For anaerobic activities, there were improvements in endurance and sprint time. Considering that the main components of energy drinks are considered legal by the World Anti-Doping Agency (WADA) and that there is scientific evidence that these drinks can produce an ergogenic action, it becomes interesting to use, improving the athlete's performance in competition orxvii the quality of training in activities of aerobic and anaerobic profile. Before the experimental study was carried out a pilot study and two volunteers, in order to develop technical data logging, training of support staff, of calibrating and evaluating the procedures and methods employed. The results of this study will not be considered in the experimental study. The first chapter and the second chapter correspond to experimental studies that aimed to assess the effects of pre-exercise ingestion of energy drinks with and without carbohydrates in cardiovascular parameters, metabolic and performance, and identify if intake of these beverages affect similarly the water balance in mineral-continuous exercise on a cycle ergometer, respectively. Both chapters have adopted the same methodology. Twelve males with age between 24,41 ± 6,68 years old and VO2max estimate (VO2MáxEs) of 54,56 ± 4,85 mL.(kg.min) -1 , regular practitioners of cycling.The exercise s protocol consisted in three experimental sessions of min in continuous exercise (65-75%VO2MáxEs), followed for a 6km sprint, respecting the interval of at least two days between sessions. This is a double blind study, in cross over randomized, which 40 min before begin exercise was ingested one of the three drinks: ED with (ED1) and without carbohydrates (ED2) or placebo drink. The amount of drink consumed was calculated individually, for offer 2mg of caffeine/kg of body weight (BW). During each experimental procedure situation, the hydration was with water in the ratio of 3 mL / kg BW immediately before the exercise, every 15 minutes, and after the final sprint. Blood samples were collected at the following times: before breakfast (- 110min), before drink ingestion (-40 min), immediately before the start of exercise (0 min), every 20 minutes of continuous exercise and final sprint. Measurements were performed respiratory exchange rates for a gas analyzer, the beginning of exercise, at the same intervals of 20 minutes and during the sprint. To evaluate fluid balance and hydration status of the subjects was recorded BW and density of urine before and after exercise, urinary volume after exercise and hematocrit. To evaluate fluid balance and hydration status of the subjects was recorded BW and density of urine before and after exercise, urinary volume after exercise. These measures allowed the monitoring of the percentage of relative and absolute dehydration and sweat rate. All experimental tests were performed in similar experimental conditions of temperature and relative humidity air. The key findings from the first chapter indicate that the time taken to complete the sprint wasxviii significantly higher compared to placebo than the other energetic supplement ED1 (p<0,001) and ED2 (p=0,003); between treatments (ED 1 and ED 2) had a significant decrease (p>0,001) in the sprint time after ED1 consumption. Heart rate and arterial pressure systolic and diastolic were similar (p>0,05) between the treatments. There was observed any difference (p>0,05) between the treatments for VO2, and VCO2, fat oxidation and plasmatic concentration of glucose and lactate. The respiratory quotient was significantly larger to the intervals of 40- 45min (p=0,005) and 55-60 min (p=0,022) ED1 treatment compared to placebo. During the sprint, the carbohydrates oxidation was larger (p=0,017) in the ED1 compared to placebo. The effort perception index in the sprint s end was larger in the placebo treatment compared to ED1 (p=0,012) and with ED2 (p= 0,022). The Key findings of second chapter indicate the parameters related to the water balance any significant difference was showed between the three experimental tests (p> 0.05). However, there was a significant statistically decrease (p<0.001) in the BW and in the urine density after exercise (p <0,05) for all treatments. Potassium concentrations were significantly higher (p <0,05) during exercise and continued after the sprint when compared to in a rest situation for all treatments. After the sprint, at the placebo treatment, a significant increase in the potassium values compared to ED1 supplements (p = 0,017) and ED2 (p = 0,012). The hematocrit concentration remained stable throughout the 60 minutes of exercise and increased significantly (p<0,05) after sprint for all treatments. Considering the environmental conditions and of exercise proposed in this study, is possible to conclude Considering the environmental conditions and of exercise proposed in this study, was possible to conclude, that energy drinks administered in an amount that provides 2mg of caffeine / kg BW, generated similar mineral-water balance over placebo for the study population group and thus not observed diuretic effect during exercise. However, ingestion of ED1, was more effective in maximizing the capacity of 6 km sprint, indicating that ED1 can be used before exercise, since there was no observable effect ergolitico.