The purpose of the study was to examine the influence of the FokI and BsmI polymorphisms of the vitamin D receptor gene on changes in insulin sensitivity with aerobic exercise training in men and women at increased risk for type 2 diabetes mellitus (T2DM). Subjects were genotyped and underwent oral glucose tolerance tests before and after six months of training. Due to mis-genotyping of the BsmI polymorphism, results for that variant were not reported. There were no significant differences between FokI genotype groups in insulin sensitivity before or after training. However, among subjects who completed training, FF homozygotes had significantly higher baseline fasting glucose and insulin levels than f allele carriers. While the FokI polymorphism does not appear to mediate training-induced changes in indices of glucose and insulin metabolism, it may influence fasting glucose and insulin levels and the development of insulin resistance in individuals at increased risk for T2DM.