Objectives
Investigations of exercise and cognition have primarily focused on healthy or demented
older adults, and results have been equivocal in individuals with mild cognitive impairment
(MCI). Our aim was to evaluate efficacy of exercise on cognition in older adults with
MCI.
Design
We conducted a meta-analysis of random controlled trials (RCTs) of exercise effects
on cognitive outcomes in adults with MCI. Searches were conducted in Medline, EMBASE,
CINAHL, PEDro, SPORTSDICUS, PsychInfo, and PubMed.
Participants
Adults aged over 65 years with MCI or Mini-Mental State Exam mean score 24–28 inclusive.
Measurements
Study quality was assessed using the PEDro scale; data on participant and intervention
characteristics and outcomes were extracted, followed by meta-analysis.
Results
Fourteen RCTs (1,695 participants; age 65–95 years) met inclusion criteria. Quality
was modest and under-powering for small effects prevalent. Overall, 42% of effect
sizes (ESs) were potentially clinically relevant (ES >0.20) with only 8% of cognitive
outcomes statistically significant. Meta-analysis revealed negligible but significant
effects of exercise on verbal fluency (ES: 0.17 [0.04, 0.30]). No significant benefit
was found for additional executive measures, memory, or information processing. Overall
results were inconsistent with benefits varying across exercise types and cognitive
domains.
Conclusions
There is very limited evidence that exercise improves cognitive function in individuals
with MCI, although published research is of moderate quality and inconclusive due
to low statistical power. Questions remain regarding the magnitude, generalization,
persistence, and mechanisms of benefits. Large-scale, high-quality RCTs are required
to determine if exercise improves cognition or reduces dementia incidence in those
with MCI.
Key Words
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Article info
Publication history
Published online: July 08, 2013
Accepted:
February 26,
2013
Received in revised form:
February 20,
2013
Received:
October 16,
2012
Footnotes
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Identification
Copyright
© 2013 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.
