MODERATE-INTENSITY AEROBIC TRAINING IMPROVES GLUCOSE-TOLERANCE IN AGING INDEPENDENT OF ABDOMINAL ADIPOSITY

OBJECTIVE: To test the hypothesis that training-related improvements i n glucose and insulin responses to an oral glucose tolerance test (OGT T) are independent of changes in abdominal adiposity. DESIGN: Adiposit y and responses to an OGTT were measured before and after a 4-month ra ndomized, controlled aerobic training program. SETTING: An academic me dical institution. PARTICIPANTS: Sixteen healthy older (73 +/- 1 year) men and women. INTERVENTION: Both the training (T) (n = 9) and contro l (C) (n = 7) groups exercised 4 times a week for 60-minute sessions. T exercised on mini-trampolines at 55 to 65% of HRmax (determined from a graded treadmill test) for 1 month and then at 75% for 3 months; C engaged in supervised stretching and yoga. MEASUREMENTS: At baseline a nd follow-up, we estimated abdominal fat (from computed tomography and anthropometry), plasma glucose, and serum insulin responses to the OG TT and fasting concentrations of free fatty acids (FFA). RESULTS: Aero bic training resulted in a 16% increase in (V) over dot O-2 peak and a 24% decrease in FFA in the T group (P < .05), but training had no eff ect on abdominal fat. In the T group, the glucose response curve shift ed to the left, and the incremental area under the glucose curve decre ased by 25% (P <.05). This improvement in glucose response occurred, h owever, only in those with impaired glucose tolerance at baseline and without any observed change in insulin response. No change in any vari ables occurred in the C group. CONCLUSIONS: Our data suggest that mode rate-intensity aerobic training has a favorable effect on glucose tole rance in older people, independent of changes in abdominal adiposity.