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.

Inclusion Criteria:

- Right handed

- English speaking

- Aged 18 to 89

- Sedentary as defined by < 120 min/week of aerobic exercise over prior 3 months

- Non-demented (MMSE 24)

Exclusion Criteria:

- Severe diabetes requiring insulin

- Cognitive-executive function deficit (MoCA < 26)