Abstract
We evaluated the effect of a 6-month-exercise training program on exercise capacity and glucose tolerance in 53 obese women (26-62y.o.47±9: mean±SD), showing an obesity level of over 20% on the obesity index (OI) with no medical problems except for an abnormality in glucose tolerance. We prescribed an exercise program based on an anaerobic threshold (AT) value obtained from ventilatory analysis during a bicycle ergometer test. The results of 75g-OGTT in all subjects significantly improved from the pre-training state (normal: 32% impaired glucose tolerance (IGT): 62%/diabetic (DM): 6%) to the post-training state (normal: 57%/IGT: 41%/DM: 2%)(P<0.01). The group which had acquired a habit of exercise training (ex-acquired group, n=30) showed both remarkable decreases in Σplasma glucose concentration (PG, -108mg/dl, P<0.01) and ΣIRI (-54μU/ml, P<0.01) during OGTT with a signficant improvement on OI, body mass index (BMI) and waist/hip ratio (W/H). However, the group which had not acquired the habit of exercise (n=23) did not show any significant change in glucose or IRI concentrations. The group which increased their V02, at the AT level, by 15% more as compared to that obtained prior to training (n=12) also showed remarkable decreases in both ΣPG (-153mg/dl, P<0.01) and ΣIRI (-54μU/ml, P<0.01), as compared with those in the group whose VO2, at the AT level, changed less than 14%(n=18).
Thus, we conclude that regular exercise training can lead to improvements in insulin sensitivity and glucose tolerance with an increase in exercise capacity in obese subjects. Therefore, education to reinforce the habit of exercise training, as a public health service, may contribute to the prevention of the onset of overt diabetes in obses subjects.
