This study looked at children with ADHD. The sample was thirty children (29 boys, 1 girl) aged 8 to 12 with a DSM-5 ADHD diagnosis, recruited in the greater Taipei area. After exclusions, 24 provided behavioral and brain-wave (ERP) data and 20 provided heart rate variability data. Each child did an exercise session and a video-watching session in a within-subject, order-counterbalanced design. Eight of the 24 were taking stimulant medication, which was withheld at least 24 hours before testing.
A single 20-minute bout of moderate-intensity aerobic exercise was followed by better performance on a flanker task. Response accuracy was higher after exercise, F(1, 23) = 15.03, p = .001, η2p = .40, with exercise at 90.4 ± 4.7% versus video at 83.7 ± 9.2%. Brain signals tied to conflict detection also improved. N2 amplitude was larger, F(1, 22) = 7.55, p = .012, η2p = .26 (− 11.4 ± 7.2 µV vs − 9.5 ± 5.7 µV), and N2 latency was shorter, F(1, 22) = 5.44, p = .029, η2p = .20 (286.9 ± 28.8 ms vs 294.6 ± 31.6 ms). These effects lasted about 60 minutes. The LF/HF ratio, a measure of heart rate variability, did not change, F's (2, 19) = 0.01–0.21, p's ≥ .81. Most participants were boys from higher-SES families, and the sample was small with low power.
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