Aerobic Exercise and Cognitive Training in Older Adults

Purpose: The purpose of this study is to examine the impact of a combined cognitive training and aerobic exercise intervention in sedentary older adults. Recent research demonstrated that older adults who participated in aerobic fitness training significantly increased their brain volume. Equally important, the demonstrated enhancement in brain size is related to improvement on specific cognitive tasks. For example, researchers demonstrated that 124 older adults randomly assigned to receive aerobic training experienced substantial improvement in cognitive performance tasks related to speed of processing and working memory. Similarly, neuroimaging studies showed that aerobically trained individuals increased brain activation during various cognitive tasks.

A growing body of research also demonstrates the beneficial effects of cognitive training in later life to promote a healthy brain. For example, researchers demonstrated cognitive interventions targeting memory, reasoning and speed of processing were effective to improve brain function. Unfortunately, despite these promising findings, the generalizability of cognitive training is limited. For example, researchers showed cognitive training tasks designed to improve reasoning, memory, planning, spatial skills and attention in over 11,000 participants demonstrated no transfer effects to untrained tasks, even when the tasks were closely related. The purpose of this study is to see if combing aerobic exercise and cognitive training can enhance the cognitive improvement of each. Specially, the investigators wish to determine if aerobic exercise done immediately before cognitive training can potentiate the improvement.

The investigators hypothesized that the aerobic exercise will potentiate and increase the generalizability of the cognitive training. Importantly, this study will focus on older adults at-risk for mobility disability. This area is of particular importance considering a large percentage of adults are entering old age and therefore likely to suffer from age-related cognitive decline and mobility disability.

Background: Currently the United States has over 23 million Veterans. Of this number, 39.1 percent are over the age of 65 a number that will greatly increase as a large percent of the US population ages. Unfortunately, many of these individuals will suffer from some form of age-related cognitive decline and/or mobility disability. Significantly, declining mental health and mobility disability are primary components of the expected 25 percent growth in health care cost related to the aging crisis in America. And, despite the fact that the United States federal government spends $100 billion dollars annually to cure and/or treat cognitive impairments, successful strategies to improve these impairments remain elusive. The proposed research will substantially advance the development of treatments for cognitive and mobility impairment because the goals explore an intervention that may potentially have pervasive effects on US Veterans quality of life and well-being from a physical as well as a cognitive standpoint.

Methods and Research Plan: To address the investigators' research question 60 adults (age 18-89) will be randomized to one of two 12 week intervention groups: 1) Cognitive Training alone (CT) or 2) Aerobic Exercise + Cognitive Training (AE+CT). The aerobic exercise arm of the study will follow the same format shown to improve a broad range of cognitive functions in older adults in previous research. The cognitive training arm will consists of a popular commercially-available brain fitness program that has demonstrated specific cognitive improvements and high adherence.

Baseline testing will consist of a battery of cognitive function that target verbal fluency, response inhibition, and working memory. Additionally, participant will undergo a structural and functional MRI. Participants will also be evaluated on their physical function as assessed by a 400 meter walk, balance tests, and questionnaires about their daily l functioning. And lastly, all participants will be assessed on their aerobic capacity and for visual outcomes and serum BDNF. Following the 12-week intervention all participants will be post tested in the same manner as the baseline testing.