Can Exercise Improve Cognitive Symptoms of Alzheimer’s
Disease? A Meta-Analysis
Gregory A. Panza, MS,*
Beth A. Taylor, PhD,*
Hayley V. MacDonald, PhD,
Blair T. Johnson,
Amanda L. Zaleski, MS,*
Jill Livingston, MS,
Paul D. Thompson, MD,
and Linda S.
OBJECTIVES: To examine the effects of exercise training
on cognitive function in individuals at risk of or diagnosed
with Alzheimer’s disease (AD).
SETTING: PubMed, Scopus, ClinicalTrials.gov, and Pro-
Quest were searched from inception until August 1, 2017.
PARTICIPANTS: Nineteen studies with 23 interventions
including 1,145 subjects with a mean age of 77.0 Æ 7.5
were included. Most subjects were at risk of AD because
they had mild cognitive impairment (64%) or a parent
diagnosed with AD (1%), and 35% presented with AD.
INTERVENTION: Controlled studies that included an
exercise-only intervention and a nondiet, nonexercise con-
trol group and reported pre- and post-intervention cogni-
tive function measurements.
MEASUREMENTS: Cognitive function before and after
the intervention and features of the exercise intervention.
RESULTS: Exercise interventions were performed
3.4 Æ 1.4 days per week at moderate intensity (3.7 Æ 0.6
metabolic equivalents) for 45.2 Æ 17.0 minutes per session
for 18.6 Æ 10.0 weeks and consisted primarily of aerobic
exercise (65%). Overall, there was a modest favorable
effect of exercise on cognitive function (d
= 0.47, 95%
conﬁdence interval (CI) = 0.26–0.68). Within-group analy-
ses revealed that exercise improved cognitive function
= 0.20, 95% CI = 0.11–0.28), whereas cognitive
function declined in the control group (d
= À0.18, 95%
CI = À0.36 to 0.00). Aerobic exercise had a moderate
favorable effect on cognitive function (d
= 0.65, 95%
CI = 0.35–0.95), but other exercise types did not
= 0.19, 95% CI = À0.06–0.43).
CONCLUSION: Our ﬁndings suggest that exercise train-
ing may delay the decline in cognitive function that occurs
in individuals who are at risk of or have AD, with aerobic
exercise possibly having the most favorable effect. Addi-
tional randomized controlled clinical trials that include
objective measurements of cognitive function are needed to
conﬁrm our ﬁndings. J Am Geriatr Soc 0:1–9, 2018.
Key words: cognition; brain; older adults; physical
pproximately 5.3 million Americans are living with
Alzheimer’s disease (AD), the sixth leading cause of
death in the United States.
The incidence of AD will more
than double by 2050. AD-related medical costs in the Uni-
ted States are estimated to exceed $1.1 trillion by 2050
unless effective methods to prevent and treat AD are iden-
Exercise training is recommended as a cost-effective
lifestyle therapeutic option to improve brain health in
older adults, with improvements in cognitive function
mediated by positive neurophysiological changes.
quently, the World Health Organization (WHO)
mends that older adults (aged ≥65) perform at least
150 minutes per week of moderate-intensity aerobic exer-
cise training (e.g., brisk walking), 75 minutes per week of
vigorous-intensity aerobic exercise training, or a combina-
tion of the two supplemented by muscle strengthening
activities (e.g., dynamic resistance training) on 2 or more
days per week. The WHO recommendations are based
upon expert opinion regarding the use of exercise as pre-
vention and treatment for AD because there are few meta-
and they have produced mixed results.
One reason for the inconsistencies among these meta-
analyses may be a lack of adherence to the high-quality
contemporary methodological standards outlined in the
Preferred Reporting Items for Systematic Reviews and
Meta-Analyses (PRISMA) statement
and the Assessment
From the *Department of Kinesiology, University of Connecticut, Storrs;
Department of Cardiology, Hartford Hospital, Hartford, Connecticut;
Department of Kinesiology, University of Alabama, Tuscaloosa,
Departments of Pyschosocial Sciences; and
University of Connecticut, Storrs, Connecticut.
Address correspondence to Gregory A. Panza, Exercise Physiologist,
Department of Cardiology, 85 Jefferson Street, JB-704, Hartford Hospital,
Hartford, CT 06102. E-mail: firstname.lastname@example.org
JAGS 0:1–9, 2018
© 2018, Copyright the Authors
Journal compilation © 2018, The American Geriatrics Society 0002-8614/18/$15.00
confirm our findings. J Am Geriatr Soc 66:487–495, 2018.
JAGS 66:487–495, 2018
2018, Copyright the Authors
2018, The American Geriatrics Society 0002-8614/18/$15.00