Efeitos da suplementação de carboidratos na prevenção do estado de overtraining em rato wistar: aspectos bioquímicos, hormonais e moleculares

• Autor(a) principal: Oliveira, Caio Victor Coutinho de
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFPB
• Texto Completo: https://repositorio.ufpb.br/jspui/handle/tede/4293
• topic: Carboidrato; Performance; Overtraining; Carbohydrate; Performance; Overtraining; CIENCIAS DA SAUDE::NUTRICAO

The ergogenic effects of carbohydrate supplementation in the sporting context are well accepted and documented in the literature. These effects have been demonstrated in various modalities and conditions of exercise, being able to improve the biochemical, hormonal, inflammatory and oxidative stress-related to physical activity. However, it has not yet been elucidated whether this ergogenic potential can be replicated under conditions of chronic and strenuous exercise, as in the case of overtraining (OT). Thus, this study aimed to verify whether carbohydrate supplementation is able to prevent and/or minimize the deleterious effects of an exercise protocol to induce OT in adult male Wistar rats. The animals (n = 32) were randomly divided into control group (C) (n = 9), exercise without supplementation (EX) (n = 10) and exercise with carbohydrate supplementation (EX-CHO) (n = 13) and underwent 11 weeks of treadmill training running, being the last 3 weeks aimed to induce the state of OT. Performance tests (Pr) were performed before the 1st week (Pr1) and at the end of the 8th (Pr2) and 11th (Pr3). Thirty-six hours after the last test, the animals were sacrificed. Levels of testosterone, cortisol, Malondialdehyde (MDA) and Creatine Kinase (CK) were measured. The activity of PI3-K, Akt-1, mTOR and GSK-3 were measured in the gastrocnemius. Weight and food consumption were monitored weekly. The training protocol was effective in causing decrement of performance when comparing Pr3 to Pr2 (decrease of 36% in EX, p> 0.05), but this reduction was not significant in the group who ingested carbohydrates. These animals of EX group showed a reduction in food intake in week 11 compared to C (17.07±0.2 g/day vs. 26.31±3.6 g/day, respectively, p <0.001), but EX-CHO kept the same intake (18.62±5.4 g/day in EX-CHO vs. 26.31±3.6 g/day in C, p> 0.05). Additionally, EX-CHO finished the protocol with corrected gastrocnemius muscle weight greater than C (5.39±0.48 g vs. 4.89±0.27 g, respectively, p=0.02), the same has not occurred in EX. The training protocol promoted decrease in testosterone (p=0.001) and elevation of MDA (p=0.009) in both exercise groups compared to C, without influence of supplemented carbohydrates in these variables (p>0.05). Meanwhile, CK and cortisol levels did not increase in both exercise groups compared to C. Considering the molecular assays, the activity of Akt-1 was higher only in EX-CHO compared to C (p=0.013), whereas mTOR showed no differences between the groups (p>0.05). We conclude that carbohydrate supplementation promotes slight attenuation in performance decrement, inhibition of anorexia and increase muscle mass in animals subjected to OT protocol. This muscle gain was accompanied by greater activity of anabolic and anti-catabolic molecular signaling Akt-1. On the other hand, it did not prevent changes in markers of OT oxidative stress, hormonal profile and muscle damage.