Efeitos da ingestão prévia de carboidrato de alto índice glicêmico sobre a resposta glicêmica e desempenho durante um treino de força

Abstract

The aim of this study was to examine the effects of pre-exercise carbohydrate ingestion on performance and glycemic response during a strength training session. Eight male volunteers performed 2 strength exercise sessions with the ingestion of a carbohydrate (maltodextrin) or placebo drink 15 minutes before each session (7 exercises with 3 sets at 70% of 1 maximum repetition). The trials were performed 7 days apart from each other and their order was randomized. Glycemia was measured at 4 times: before the drink ingestion, 15 minutes after the drink ingestion, halfway through the training and at the end of the exercise session. The total performance was affected by variation on achieved repetitions in the different days, which were inserted in the total load rate analysis performed in the respective sessions (repetitions • sets • load). Heart rate was continuously monitored and lactate concentration was measured at the end of session. Glycemia increased only at 15 minutes after the carbohydrate drink ingestion (from 98.25 ± 17.77mg/dL to 133.12±22.76 mg/dL, p= 0.015) , while on the placebo drink day no significant changes were observed (from 98.25 ± 13.69 mg/dL to 94.38 ± 12.21 mg/dL, p=1.000). The total load rate, heart rate and final lactate concentration were not different in the two strength exercise sessions. Although pre-exercise glycemia was increased after the carbohydrate drink ingestion, the results do not indicate that carbohydrate ingestion before strength exercise session can be an efficient supplementation in order to improve physical performance.