Effects of an acute bout of exercise on cognitive function in adults with cognitive impairment: a systematic review with meta-analysis of randomized controlled trials

Background: Acute exercise has been demonstrated to improve cognitive functioning among the general population. We provide the first review to establish the evidence for acute exercise to improve cognitive function among adults with cognitive impairment (CI). Methods: We conducted a systematic review with meta-analysis of randomized controlled trials that investigated the effects of a single exercise session on cognitive function. Data sources were PubMed, SportDiscus, PsychINFO, Cochrane Central, PEDro, and Embase. Eligibility criteria were randomized controlled trials of acute exercise with participants aged 18+ and physician diagnosed or self-reported CI. We used dual data abstraction, risk-of-bias assessment, and strength of evidence assessment. We pooled results using the inverse variance heterogeneity model or with narrative synthesis. Results: Fifteen studies (8 parallel group and 7 crossover) representing 500 participants were included, 10 in the meta-analysis. Acute exercise significantly improved executive function (moderate evidence, 9 studies, 330 participants, g = 0.33, small effect, 95% CI, 0.07– 0.59, P = .01, I2 = 26.77%). However, this was only for high risk of bias/crossover studies. Acute exercise improved reaction time but not significantly (very low evidence, 7 studies, 271 participants, g = 0.17, small effect, 95% CI, −0.20 0.54, P = .36, I2 = 50.18%). Narratively, improvements were noted for memory, but there was mixed evidence for attention, information processing, and motor memory. Conclusions: Acute exercise provides a small improvement in executive function and may also improve reaction time and memory for adults with CI. Additional research is needed before reaching an evidence-based consensus on the promotion of acute exercise for adults with CI.