A 2022 review pooled 15 randomized trials of physical exercise covering 734 children with ADHD, aged 5 to 15. The trials came from ten countries. Exercise ranged from swimming and yoga to taekwondo and horseback riding. Sessions ran 25 to 90 minutes, one to five times a week, for 5 weeks to 1.5 years. Comparison groups got no program, a waiting list, story listening or medication, among others. The authors rated one trial high quality and 14 medium quality.
Compared with the other groups, children who exercised did better on attention, executive function and motor skills. Exercise did not make a clear difference to hyperactivity, depression, social problems or aggressive behavior. Even so, the authors argue exercise can ease hyperactivity and depression, blaming small samples and differing exercise plans.
For executive function, the authors pointed to closed-skill exercise in 70-minute sessions, twice a week, for 12 to 14 weeks. But they tested each factor alone, not as a combined program. The 12 to 14 week group also showed a smaller benefit than the 1.5 year group.
Few trials described how they hid group assignment or kept children, researchers and assessors unaware of groups. The review only included studies published in Chinese and English. The authors suggest exercise improved attention, executive function and motor skills in these children, but they call for more research on the best amount of exercise.
The numbers Stats and what the terms mean
The statistics behind the plain-language claims above.
- Sun, 2022: attention, exercise versus control (9 studies, 352 participants), SMD = − 0.60, 95% CI [− 1.10, − 0.11], I2 = 76%.
- Sun, 2022: executive function, exercise versus control (8 studies, 319 participants), SMD = 1.22, 95% CI [0.61, 1.82], p < 0.01.
- Sun, 2022: motor skills, exercise versus control (4 studies, 191 participants), SMD = 0.67, 95% CI [0.22, 1.12], p < 0.01.
- Sun, 2022: hyperactivity, exercise versus control (4 studies, 161 participants), SMD = 0.06, 95% CI [− 0.26, 0.37], p = 0.72.
- Sun, 2022: depression, exercise versus control (4 studies, 98 participants), SMD = − 0.72, 95% CI [− 1.55, 0.11], p = 0.09.
- Sun, 2022: social problems, exercise versus control (4 studies, 117 participants), SMD = − 0.27, p = 0.14.
- Sun, 2022: aggressive behavior, exercise versus control (3 studies, 78 participants), SMD = − 0.24, 95% CI [− 0.69, 0.21], p = 0.30.
- Sun, 2022: executive function in programs lasting 12 to 14 weeks, SMD 1.74, 95% CI 0.53 to 2.94.
- Sun, 2022: executive function in programs lasting 1.5 years, SMD 2.12, 95% CI 1.33 to 2.91. What the terms mean:
- SMD the size of the difference between groups in standard units. Roughly, 0.2 is small, 0.5 is moderate and 0.8 is large. A minus sign shows the direction of the change, not its size.
- 95% CI the range the true effect most likely falls in. A range that crosses zero means no clear effect.
- p how likely a result this large would be by chance alone. Below 0.05 is usually treated as unlikely to be chance.
- I2 how much the studies disagreed with each other. Higher means more disagreement.
Source: Sun W, Yu M, Zhou X. Effects of physical exercise on attention deficit and other major symptoms in children with ADHD: A meta-analysis. Psychiatry Research (2022). doi:10.1016/j.psychres.2022.114509