February 5, 2022
Executive function(EF) is associated with the prefrontal cortex. It includes three core components: inhibitory control, cognitive flexibility, and working memory. Inhibitory control is the ability to avoid distractions, inhibit or control impulsive responses, and change to more thoughtful responses. Cognitive flexibility involves switching mental tasks or strategies, seeing problems from multiple perspectives, and identifying different ways of solving them. Working memory involves holding information in the mind ready for an ongoing processing.
Persons with neurodevelopmental disorders, including ADHD, are known to have EF deficits relative to their normally-developing counterparts.
An international research team conducted a comprehensive search of the peer-reviewed medical literature to identify studies that have explored how physical activity affects those deficits in persons with neurodevelopmental disorders, specifically ADHD.
They identified 34 studies with 1,058 participants, of which 13 with 400 looked specifically at ADHD. There was substantial geographic diversity in the ADHD studies, spanning the globe: the United States, Canada, Switzerland, Taiwan, South Korea, Iran, Israel, and Tunisia.
Among the ADHD studies, a meta-analysis found physical activity improved executive functions overall, with a large effect size. More specifically, it included twelve tests of inhibitory control, four for working memory, three for cognitive flexibility, and one each for switching and planning (there was often more than one tester in the study).
There was no sign of publication bias. There was, however, substantial heterogeneity between studies. A further breakdown indicated substantial divergence by type of physical activity, with a large effect size for sports, medium effect sizes for aerobic exercise and motor skills training, and small effect size for exergaming (video games that are also a form of exercise).
Session time also made a big difference. Sessions at least an hour long had large effect sizes, those between 45 minutes and an hour had medium effect sizes, and shorter sessions had smaller effect sizes.
Improvements in inhibitory control had large effect sizes, those in cognitive flexibility had medium-to-large effect sizes, and those in working memory had small-to-medium effect sizes. All of which suggest ADHD patients can substantially improve executive functions through persistent and protracted physical exercise.
Ming-Chih Sung, Byungmo Ku, Willie Leung, Megan MacDonald, "TheEffect of Physical Activity Interventions on Executive Function Among People with Neurodevelopmental Disorders: A Meta-Analysis," Journal of Autism and developmental Disorders(2021), published online,https://doi.org/10.1007/s10803-021-05009-5.