THE EFFECT OF PREEXERCISE CARBOHYDRATE STATUS ON RESISTANCE EXERCISE PERFORMANCE

The purpose of this study was to determine the effect of a high vs. a low preexercise carbohydrate (CHO) diet on performance during multiple sets of resistance exercise. Eleven resistance-trained males performe d cycle ergometry to deplete quadriceps muscle glycogen stores, follow ed by 48 hr of a high (HICHO) or a low (LOCHO) CHO diet. Subjects then performed five sets each of squats, leg presses, and knee extensions (resistance = 15 RM) to failure. Blood samples were taken before and d uring exercise for determination of glucose and lactate (LA). No diffe rences in performance (repetitions x weight lifted) were observed (HIC HO = 15,975 +/- 1,381 and LOCHO = 15,723 +/- 1,231 kg). Blood glucose was significantly higher after exercise for HICHO compared to LOCHO (H ICHO = 4.8 +/- 0.2 vs. LOCHO = 3.9 +/- 0.2 mmol L-1). No differences i n LA accumulation were observed. The data indicated that preexercise C HO status did not affect resistance exercise performance. Further, the differences in blood glucose and the similarity in LA responses sugge st that glycolysis was maintained in the LOCHO condition, and there ma y have been an increased reliance on blood glucose when preexercise CH O status was low.