In reply
Recently, we described the results of a controlled, 6-month trial of aerobic exercise for older adults with mild cognitive impairment demonstrating favorable effects on cognition.1 Our findings and those of a number of other controlled trials currently under way will provide important evidence regarding the effects of exercise on brain health and cognition for normal aging and neurodegenerative disease. Controlled trials are critical to ascertain cause and effect but the remedial value of such strategies depends on successful implementation in community-based populations. The results of our study, although preliminary, raises the question of how we might translate our findings for community consumption.