Yes, there is evidence that martial arts training for children can lead to better academic outcomes. Studies have shown that children who participate in martial arts programs demonstrate improved attention span, cognitive function, and memory.
Additionally, the discipline and focus required for martial arts training can carry over into academic performance by helping children develop better study habits and time management skills.
The confidence and self-esteem gained through martial arts training can also help children perform better academically.
Sources
https://www.psychologytoday.com/us/blog/the-athletes-way/201505/martial-arts-training-improves-attention-span-in-children
https://www.cbc.ca/parents/learning/view/how-karate-can-help-your-kids-do-better-in-school
https://www.healthline.com/health-news/how-martial-arts-can-help-improve-school-performance#1
https://www.usa.gov/features/5-ways-martial-arts-can-boost-your-childs-academic