Among middle-aged and older men with type 2 diabetes, their capacity for exercise is related to their likelihood of dying over a 7-year period, according to a new study.

Dr. Peter Kokkinos from the Veterans Affairs Medical Center, Washington, D.C., and colleagues say their findings show a strong association between increased exercise capacity and lower mortality risk.

Between 1986 and 2007, 1703 African American men and 1445 Caucasian men with type 2 diabetes completed a maximal exercise test. This classified them as "low-fit," "moderate-fit," or "high-fit."

During 7 years of follow-up, "a graded reduction in mortality risk was noted with increased exercise capacity for both races," the researchers report in the medical journal Diabetes Care.

Among African Americans, the death rate was 46 percent in the low-fit group, 27 percent in the moderate-fit group, and 15 percent in the high-fit group. Corresponding rates among Caucasians were 37 percent, 19 percent, and 9 percent.

The results suggest, the investigators say, that the exercise-related reduction in mortality may be stronger and more graded for Caucasians than for African-Americans.

It's important to note, the researchers say, that the men in their study for the most part came from a relatively low socioeconomic background, whereas most information on the benefit of fitness in diabetics has come from more privileged populations.

"Thus, our findings support the notion that higher exercise capacity is associated with lower all-cause mortality in men with type 2 diabetes, independent of socioeconomic status," Kokkinos and colleagues point out.

The findings, they add, "extend the public health message regarding the health benefits of cardiorespiratory fitness to men with diabetes ... and that health care professionals should encourage diabetic subjects to initiate and maintain a physically active lifestyle consisting of moderate-intensity activities."