The study included children aged 8 to 12 with an ADHD diagnosis from the greater Taipei area. Almost all were boys (29 boys, 1 girl). Each child did one bout of moderate aerobic exercise and one session of watching a video, in a balanced order. After exclusions, the task results came from 24 children. Heart data came from fewer children (20). Some children took stimulant medicine (8 of the 24). It was stopped at least 24 hours before testing.
After exercise, the children were more accurate on a task that tests the ability to hold back a quick response. Their accuracy was higher than after the video (90.4% versus 83.7%). Brain recordings also showed they detected conflicting cues more effectively. These gains held for 60 minutes after exercise. Exercise did not change a heart rhythm measure of nervous system balance during recovery.
This was a preliminary study, and most children were boys from relatively advantaged families, so the results may not apply to girls or to less advantaged children. Most had the combined ADHD subtype (about 70%). Heart data were collected only at two later time points (30 and 60 minutes), so they say nothing about the time just after exercise. The authors call for larger studies that account for medication.
The authors frame a single 20-minute bout of moderate aerobic exercise as a possible complementary, non-drug approach for children with ADHD.
Source: Chien-Lin Yu, Shu‐Shih Hsieh, Ting‐Yu Chueh, et al.. The effects of acute aerobic exercise on inhibitory control and resting state heart rate variability in children with ADHD. Scientific Reports (2020). doi:10.1038/s41598-020-76859-9