Beneficial effect of short-term endurance training on glucose metabolism during rehabilitation after coronary bypass surgery

Aims: Our study was aimed at determining whether beneficial modification of carbohydrate metabolism can be obtained after a short-term training progra m and whether it is associated with an increase in binding and degradation of I-125-insulin by erythrocyte receptors that suggests a decrease in insul in resistance, Methods: The study was conducted in a group of 20 patients aged 56 +/- 1.9 years (mean +/- SEM), within 1 to 6 months after coronary bypass surgery. A ll patients completed 15 training sessions based on 30 min of cycling with a constant load. Before and after a 3-week training program, glucose, insul in, and C-peptide blood levels, as well as binding and degradation of I-125 -insulin by erythrocyte receptors, were determined. Results: A statistically significant decrease was found in the blood glucos e level, from 111.2 +/- 4.2 to 97.8 +/- 3.5 mg/dL (p < 0.01); this decrease was not accompanied by significant insulin concentration changes, There wa s also a significant increase in insulin binding, from 0.535 +/- 0.059 to 0 .668 +/- 0.042 pg I-125/10(11) RBCs (p < 0.01), and degradation from 7.64 /- 0.54 to 9.49 +/- 0.58 pg I-125/10(11) RBCs (p < 0.05). Conclusion: The results indicated that even short-term endurance training i n patients rehabilitated after coronary bypass surgery induced favorable mo dification of glucose metabolism, presumably caused by a decrease in insuli n resistance.