7 CONSECUTIVE DAYS OF EXERCISE LOWERS PLASMA-INSULIN RESPONSES TO AN ORAL GLUCOSE CHALLENGE IN SEDENTARY ELDERLY

Objective: To assess the effects of 1 and 7 consecutive days of exerci se on glucose and insulin responses to an oral glucose challenge. Desi gn: Intervention group assessed at baseline and after 1 and 7 days of exercise. Setting: Academic medical institution. Participants: Nine he althy 60 to 80-year-old men and women Intervention: Seven days of 50 m inutes of exercise at 70% VO2 max. Measurements: Body weight, body com position, and glucose and insulin levels and responses to an oral gluc ose challenge at baseline and after 1 and 7 days of exercise. Main Res ults: Fasting plasma insulin levels and plasma insulin responses to an oral glucose challenge were reduced by 15% and 20%, respectively, wit h 7 consecutive days of exercise that resulted in no change in body we ight or body composition. No changes in glucose or insulin levels or r esponses to the oral glucose challenge were evident after a single day of exercise. Conclusion: The hyperinsulinemia associated with aging c an be blunted significantly by repeated bouts of exercise in the elder ly, independent of any changes in body composition.