If you have prediabetes, walking briskly a mile or two a day, on average, is one of the best ways to improve blood sugar control, according to a study in the journal Diabetologia. Prediabetes, also called impaired glucose tolerance, refers to modestly elevated blood sugar levels and often progresses to full-blown diabetes. Researchers from Duke University divided 237 people with prediabetes into four groups. One group followed the Diabetes Prevention Program, considered the gold standard, which requires calorie reduction and moderate exercise (equal to 7 1/2 miles of brisk walking a week). The three other groups only exercised: low amount at moderate intensity (equal to 7 1/2 miles of brisk walking a week); high amount at moderate intensity (equal to 11 1/2 miles of brisk walking a week); or low amount at high intensity (equal to 11 1/2 miles of jogging a week). After six months, the Diabetes Prevention Program group had the biggest improvement in blood sugar control, followed by the group that did a high amount of moderate exercise. The other two exercise groups benefited less.