A community-based approach to trials of aerobic exercise in aging and Alzheimer's disease

Abstract

The benefits of exercise for aging have received considerable attention in both the popular and academic press. The putative benefits of exercise for maximizing cognitive function and supporting brain health have great potential for combating Alzheimer's disease (AD). Aerobic exercise offers a low-cost, low-risk intervention that is widely available and may have disease modifying effects. Demonstrating that aerobic exercise alters the AD process would have enormous public health implications. The purpose of this paper is to report the protocol of a current, community-based pilot study of aerobic exercise for AD to guide future investigation. This manuscript provides 1) an overview of possible benefits of exercise in those with dementia, 2) a rationale and recommendations for implementation of a community-based approach, 3) recommendation for implementation of similar study protocols, and 4) unique challenges in conducting an exercise trial in AD.

Figure 1

shows the power of our study at testing different effect sizes using one-sided two sample t-test at alpha level of .05 when the attrition rate is 20% or 0. The observed effect sizes of Logic Memory from the 7 studies in the literature are marked in the plot. Each number on the plot denotes the sample size of the corresponding study. From this plot, a reasonable estimate of the effect size of logic memory is about .45 and the power is within .56 to .64 depending on the attrition rate. The power of the study is from .64 to .72 if the effect size is .5.