Physical exercise helps keep brains healthy but acute concussion, a brain injury that can go undetected, can be fatal. Repeated concussions are known to cause neurodegenerative disease in boxers. Could rugby players suffer in the same way?

To find out Professor Damian Bailey of the Neurovascular Research Laboratory at the University of South Wales has developed tests that focus on the brain's control of it's own blood flow and oxygen. Bailey says: "Understanding of the causes and long-term brain effects of concussions is poor. Concussions can be hard to spot, do not require a direct blow to the head and in 90 per cent of cases do not lead to unconsciousness.

"We have found evidence of accelerated brain ageing leading to impaired mental agility and dementia symptoms in retired rugby players."

Bailey has put over 250 rugby players through tests designed to challenge the brain. Putting the brain under pressure through novel types of exercise, high-fat meals and changes in oxygen/carbon dioxide has detected subtle and enduring signs of brain injury. Study participants were matched against non-rugby playing controls of similar age and fitness. The findings are being submitted for scientific publication.

"Our research could change the way rugby is played and even the game's rules, so accurate results are essential," says Bailey. "We believe that our battery of lab tests can pick up subtle effects and provide a more scientific means of determining when the brain has fully recovered - or not, as we have seen in some of the sedentary retired players. Our approaches include electron paramagnetic resonance spectroscopy and ozone-based chemiluminescence to measure blood levels of free radicals, tiny molecules that in excess can damage the brain and impair blood flow and oxygen delivery."

The lab also uses high-performance data acquisition hardware to capture a wide variety of signals from the brain, heart, lungs and muscles including blood flow and oxygenation, blood pressure, heart rate, ventilation and the composition of expired gases.

Bailey says: "If my research confirms there is a clear risk of brain injury from concussions I hope it will be used to inform return to play decisions and help prevent some of the more damaging long-term changes to the brain that can occur when players retire."