Aerobic exercise and neurocognitive performance: a meta-analytic review of randomized controlled trials

Abstract

Objectives: 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of several previous reviews and meta-analyses, they have been hampered by methodological shortcomings and are now outdated as a result of the recent publication of several large-scale, randomized, controlled trials (RCTs).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.

Figures

Figure 1

Effect of aerobic exercise on attention and processing speed (n = 24). Individuals randomized to aerobic exercise treatment exhibited improved attention and processing speed relative to controls (g = .158 [95% CI: .055 to .260], P = .003). Each study is denoted with a circle, with larger sample sizes corresponding to larger marks.

Figure 2

Effect of aerobic exercise on executive function (n = 19). Individuals randomized to aerobic exercise treatment exhibited improved executive function (g = .123 [95% CI: .021 to .225], P = .018). Each study is denoted with a circle, with larger sample sizes corresponding to larger marks.

Figure 3

Effect of aerobic exercise on working memory (n = 12). Individuals randomized to aerobic exercise treatment did not exhibit significant improvements in working memory relative to controls (g = .032 [95% CI: −.103 to .166], P = .642). Each study is denoted with a circle, with larger sample sizes corresponding to larger marks.

Figure 4

Effect of aerobic exercise on memory (n = 16). Individuals randomized to aerobic exercise treatment exhibited improved memory relative to controls (g = .128 [95% CI: .015 - .241], P = .026). Each study is denoted with a circle, with larger sample sizes corresponding to larger marks.