Brain scans of karate experts show that there are subtle differences in certain areas of brain that probably enables them to punch harder from a very close range.

The study included 12 people who had black belts in Karate who have been practicing Karate for around 13 years and 12 people who exercised regularly but didn't practice Karate.

Researchers Imperial College London and UCL, took brain scans of the participants while they punched. All participants had to punch at an object from a distance of 5 cm (a little under two inches).

As expected, Karate experts punched harder than other people. Researchers found that timing defined a good punch. Karate experts had more synchronized wrist-shoulder movements that helped them generate a good force while punching.

"The Karate black belts were able to repeatedly coordinate their punching action with a level of coordination that novices can't produce. We think that ability might be related to fine-tuning of neural connections in the cerebellum, allowing them to synchronize their arm and trunk movements very accurately," said Dr. Ed Roberts, from the Department of Medicine at Imperial College London, lead author of the study.

For the study, researchers used diffusion tensor imaging (DTI) - an imaging technique used to analyze the white matter in the brain.

The brain scans showed that there were some structural differences in the brains of Karate experts and the control group. The differences were mostly seen in the cerebellum and primary motor cortex, the regions of the brain that controls movement.

Researchers found that a co-relation existed between the structural difference in the brains and the level of wrist-shoulder synchronicity.

"We're only just beginning to understand the relationship between brain structure and behavior, but our findings are consistent with earlier research showing that the cerebellum plays a critical role in our ability to produce complex, coordinated movements," added Dr. Roberts.

The brain scans also co-related with the age and total experience of the experts. Researchers say that the structural differences in the brain and the fine-tuning of the areas of brain responsible for movement are related to the punching ability of the experts.

However, researchers say that future studies will help in understanding what really occurs in a Karate black belt holder's brain.

"There are several factors that can affect the DTI signal, so we can't say exactly what features of the white matter these differences correspond to. Further studies using more advanced techniques will give us a clearer picture," said Roberts in a news release.

Earlier studies have shown that Karate experts' technique of stabilizing the body during and after a punch also improves their punching abilities.

The study was published in the journal Cerebral Cortex.