Getting some play today on the net - we are what we practice:

Black belts’ white matter shows how a powerful punch comes from the brain

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The study, published in the journal Cerebral Cortex, looked for differences in brain structure between 12 karate practitioners with a black belt rank and an average of 13.8 years’ karate experience, and 12 control subjects of similar age who exercised regularly but did not have any martial arts experience.

[…]

Brain scans showed that the microscopic structure in certain regions of the brain differed between the two groups. Each brain region is composed of grey matter, consisting of the main bodies of nerve cells, and white matter, which is mainly made up of bundles of fibres that carry signals from one region to another. The scans used in this study, called diffusion tensor imaging (DTI), detected structural differences in the white matter of parts of the brain called the cerebellum and the primary motor cortex, which are known to be involved in controlling movement.

[…]

I strongly suspect that if they tested other groups which have long practiced coordinated movements - such as dancers or acrobats - that they’d find something similar.