The incidence of cognitive impairment that does not meet the diagnostic criteria for dementia (CIND) is currently two-fold greater than the incidence of Alzheimer's disease and related dementia. Numerous studies have demonstrated that those who are more physically active are less likely to experience cognitive decline and dementia later in life. This study examined the effect of combining a group-based exercise program with dual-task training on cognitive function in active older adults with indications of CIND.

Subjects were included from an exercise class at the Canadian Centre for Activity and Aging (CCAA), ranging from 55 to 90 years of age. All were free of dementia or other neurologic or psychiatric disorders. Over the 26 weeks of the study, the participants were engaged in a group based exercise program, two to three times per week, plus a weekly square stepping exercise (a visuospatial working memory task that requires a stepping response). The intervention group was required to respond to cognitively challenging questions during the square stepping exercise. The primary outcome measure was the change in global cognitive function (GCF), based upon a cumulative score from a neuropsychological battery.

At 26 weeks, greater improvement was seen in standardized GCF in the treatment group than in the control group (P＝0.04). At week 26, the treatment group's standardized verbal learning and memory scores were 0.3 standard deviations, and their verbal fluency scores 0.62 standard deviations higher, than those of the control group.

This study of elderly individuals found that a 26 week program of group based exercise, combined with dual task training, improved cognitive function better than did group based exercise alone.