Participating in a structured exercise program that is planned, individualized and supervised, and that includes aerobic exercise, resistance training or both, is your best bet for lowering glucose levels.
An analysis of 23 studies showed that people who completed structured exercise enjoyed a greater drop in glucose levels than those who didn't. Aim for 150 minutes per week - better yet, a little more. Exercising more than 150 minutes lowered glucose the most, and activities didn't have to be vigorous. High intensity exercises were no better than moderate level activity, such as brisk walking, for lowering glucose.
Source: J. of the American Medical Association, vol. 305, p. 1790; Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50