Efeitos bioquímicos da suplementação de carboidratos após uma competição simulada de Short Duathlon Terrestre

Abstract

RESUMOA proposta do presente estudo foi investigar os efeitos bioquí-micos da suplementação de carboidratos em uma competição simulada de short duathlon terrestre. A amostra foi constituída de quatorze duatletas, aos quais foram dados suplementos de uma bebida com carboidrato em uma solução a 6% de maltodextrina (g1), placebo (g2) e solução a 6% de glicose (g3), em três momentos distintos da competição simulada: 30 minutos antes da prova (500ml), a cada 15 minutos durante essa competição (200ml) e imediatamente após o término desta (300ml). Amostras de sangue foram coletadas em dois momentos -antes e imediatamente após o final da competição -para análise da glicemia, lactato, insulina e cortisol. Verificaram-se diferenças significativas, em relação aos níveis de glicemia entre g1 e g2, na fase pós-competição. Quando analisado o lactato, também se verificou uma diferença significativa em g1 e g2 na fase durante a competição. Da mesma forma, foram observadas diferenças significativas nas concentrações de cortisol durante a competição (g1) e pós-competição (g2). A conclusão desse estudo, baseada nos dados obtidos das amostras sanguíneas, foi que a suplementação de maltodextrina fornece indicativos bioquímicos que favorecem sua utilização em competições como o short duathlon terrestre.Palavras-chave: carboidratos, competição, glicose, lactato, insulina, cortisol. ABSTRACT Biochemical Effects of Carbohydrates Supplementation in a Simulated Short Land Duathlon Competition This study aimed to investigate the biochemical effects of carbohydrates supplementation in a simulated short land duathlon competition. Sample size consisted of 14 athletes that ingested supplements of a 6% maltodextrin solution (G1), placebo (G2), and a 6% glucose solution (G3), in three different moments of the simulated competition: 30 min before de competition (500ml), every 15 min during the competition (200ml), and immediately after the end of the competition (300ml).Blood sampling was obtained during two stages of the competitionbefore and immediately after the end -to blood glucose, lactate, insulin and cortisol analyses. We found significant differences at glucose concentrations between G1 and G2 after competition. When lactate concentrations were analysed, it was also found a significant difference in G1 and G2 during the competition, as well, in the cortisol concentrations during the competition (G1) and after competition (G2). We conclude that the maltodextrin supplementation provides biochemical evidence that favors its ingestion in simulated short land duathlon competition.

Effects of Carbohydrates Supplementation and Physical Exercise

“…The catabolism of glycogen is the primary mean used to obtain energy in order to exercise the change from low to high intensity which can quickly supply the ATP during oxidative processes. Mamus (2004) have found that the amount of available carbohydrates is crucial to regulate fat metabolism in exercise. The increased oxidation of carbohydrates caused by eating foods with a high glycemic index, which increase blood glucose levels and the rate of blood insulin, significantly dampens the breakdown of free fatty acids from adipose tissue during exercise [17].…”

“…Besides the dietary manipulation and the training conducted in the week prior to the competition, other factors may influence the ability of the athlete to maintain the muscles active. Mamus, et al (2004) argues that during the training is necessary a rich supply of these nutrients in order to succeed in the competition, because it is during this period that increases the energy expenditure and consequently occurs an increase in caloric intake to maintain the body weight and the correct functioning of the body [17]. For example Dill, et al (1932), studied the effects of carbohydrate intake in a race using a trained dog at the right intensity [21].…”

“…The goal of a high-carbohydrate diet in pre-competition phase is to increase stored glycogen and prevent from its depletion when the training is conducted thoroughly successive days, requiring, to improve the performance, a diet with 65-75% of calories coming from carbohydrates [5,14]. Depending on the pre-training situation, this intake can reach 80% of total energy calculated as necessary [10].…”

“…This reduced level of work is directly connected with the production and the release of energy by the oxidation of fats, which are replaced primary role in energy production in this period. Thus, it is necessary to replace carbohydrates throughout the competition (pre, during and post) considering type, concentration and form of the carbohydrate intake [10,17,23,28]. A proper carbohydrate intake is essential for optimizing the initial glycogen stores in muscles, maintaining blood glucose levels during the exercise and ------an adequate replenishment of glycogen stores during recovery (American Dietetic Association, Dietitians of Canada, American College of Sports [29].…”

“…The power of an athlete directly influences his physical performance [4]. In the pre-competition stage stored glycogen increases and prevents from depletion [5]. Supplementation during competition aims to replenish lost fluids and carbohydrates [6].…”