Cognitive and Linguistic Benefits of Aerobic Exercise: A State-of-the-Art Systematic Review of the Stroke Literature.

The 27 studies used a wide variety of cognitive measures, many of them broad screeners (MMSE, MoCA) that are not sensitive to change in a single domain, making it hard to say what actually improved. Language was assessed only through subtests of screeners or self-report scales. No study used a performance-based test of language, so the review cannot speak to whether exercise affects real communication ability. People with aphasia were frequently excluded or their aphasia status was not reported. Only 12 people with aphasia across three studies had data used, and their aphasia profiles were inadequately described. Methodological quality varied widely (PEDro+ scores 3 to 10 out of 12), with common gaps in blinding, allocation concealment, and treatment fidelity reporting. Only English-language, peer-reviewed articles from 2008 onward were included, and the authors note possible publication bias toward positive findings. Exercise intensity, modality, frequency, and duration varied so much across studies that no consistent pattern could be identified to explain which programmes produced cognitive gains.

Funded by the Academy of Neurological Communication Disorders and Sciences and Northern Illinois University. The authors declare no commercial or financial relationships that could be construed as a conflict of interest.

Do not read the positive cognitive findings as evidence that aerobic exercise will improve a patient's aphasia. Only two studies showed any language gain, both via a self-report scale, and no study used a performance-based language measure. The 12 people with aphasia whose data were used had inadequately described language profiles, so their cognitive scores may reflect language difficulty rather than the domain being tested.