Aerobic exercise and neurocognitive performance: a meta-analytic review of randomized controlled trials.
OBJECTIVE
To assess the effects of aerobic exercise training on neurocognitive performance. Although the effects of exercise on neurocognition have been the subject of several previous reviews and meta-analyses, they have been hampered by methodological shortcomings and are now outdated as a result of the recent publication of several large-scale, randomized, controlled trials (RCTs).


METHODS
We conducted a systematic literature review of RCTs examining the association between aerobic exercise training on neurocognitive performance between January 1966 and July 2009. Suitable studies were selected for inclusion according to the following criteria: randomized treatment allocation; mean age > or =18 years of age; duration of treatment >1 month; incorporated aerobic exercise components; supervised exercise training; the presence of a nonaerobic-exercise control group; and sufficient information to derive effect size data.


RESULTS
Twenty-nine studies met inclusion criteria and were included in our analyses, representing data from 2049 participants and 234 effect sizes. Individuals randomly assigned to receive aerobic exercise training demonstrated modest improvements in attention and processing speed (g = 0.158; 95% confidence interval [CI]; 0.055-0.260; p = .003), executive function (g = 0.123; 95% CI, 0.021-0.225; p = .018), and memory (g = 0.128; 95% CI, 0.015-0.241; p = .026).


CONCLUSIONS
Aerobic exercise training is associated with modest improvements in attention and processing speed, executive function, and memory, although the effects of exercise on working memory are less consistent. Rigorous RCTs are needed with larger samples, appropriate controls, and longer follow-up periods.
Box 3119, Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA. Smith562@mc.duke.edu
Patrick J
PJ
Smith
James A
JA
Blumenthal
Benson M
BM
Hoffman
Harris
H
Cooper
Timothy A
TA
Strauman
Kathleen
K
Welsh-Bohmer
Jeffrey N
JN
Browndyke
Andrew
A
Sherwood
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001288:Attention / Q000502:physiology; D003071:Cognition / Q000502:physiology; D003072:Cognition Disorders / Q000175:diagnosis / Q000628:therapy*; D056344:Executive Function / Q000502:physiology; D015444:Exercise / Q000502:physiology* / Q000523:psychology; D005081:Exercise Therapy / Q000379:methods; D006801:Humans; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data*; D016896:Treatment Outcome