RESUMO
PURPOSE: The major aims of this study were to determine whether a single session of resistance exercise would alter insulin sensitivity, glucose effectiveness, and C-peptide response to glucose challenge in a group of previously sedentary, postmenopausal women. METHODS: Ten postmenopausal women (aged 57.5 +/- 1.6 yr) were studied. Each participant underwent two frequently sampled intravenous glucose tolerance tests (FSIVGTT): without prior exercise (no exercise), and postexercise (15 h after a session of resistance exercise: three sets of 10 repetitions performed at 50%, 75%, and 100% of 10-repetition maximum for 7 exercises). Insulin sensitivity and glucose effectiveness were determined according to Bergman's minimal model procedure. In addition, C-peptide concentration and glucose disappearance were measured. RESULTS: There was no significant difference between trials for insulin sensitivity, glucose effectiveness, glucose disappearance, or area under the curve (AUC) for glucose or insulin during the glucose challenge. AUC for C-peptide tended (P = 0.059) to be 10% higher in the postexercise versus no exercise trial, and C-peptide values were significantly (P < or = 0.02) higher at several time points (60, 70, 140, and 180 min) during the postexercise compared with no exercise trial. CONCLUSIONS: In contrast to previously reported results with young men and women after a single bout of endurance exercise, insulin sensitivity was unaltered by a single session of resistance exercise in postmenopausal women. Higher plasma C-peptide values concomitant with unchanged insulin values provide evidence that resistance exercise may have induced a slightly higher insulin secretion and a proportional increase in insulin clearance.