World Rugby has welcomed the findings of a study which revealed concerning evidence of a considerably increased risk of motor neurone disease among former players and called for the elimination of contact training and a reduction in the global calendar.

A study led by the University of Glasgow looking at former Scotland internationals – from both the amateur era and later professional players – found ex-rugby players had more than twice the risk of a neurodegenerative disease, and a 15-times higher risk of a motor neurone disease diagnosis.

Consultant neuropathologist Prof Willie Stewart, who led the research, said it raised immediate questions for rugby authorities to mitigate the risks.

“I am genuinely concerned about what is happening in the modern game, and that if, in 20 years’ time, we repeat this study we would see something even more concerning” Stewart said.

“Rugby has talked a lot and done a lot about head injury management and whether it can reduce head injury during (training). Those conversations have gone on a while and the pace of progress is pretty slow.

“This should be a stimulus to them to pick up their heels to make some pretty dramatic changes as quickly as possible to try and reduce risk.

“Instead of talking about extending seasons and introducing new competitions and global seasons they should be talking about restricting it as much as possible, cutting back on the amount of rugby we’re seeing and getting rid of as much training as possible.

“Things like that have to be addressed pretty rapidly.”

Asked by the PA news agency about those specific recommendations, a World Rugby spokesperson said: “World Rugby introduced new contact training load limit guidance of 15 minutes per week in August 2021.

“This is currently being evaluated as part of the biggest ever study in sport of smart mouthguard technology. The results will inform the future of this important area.

“Equally, everyone in the sport is committed to determining an optimised men’s calendar, like the women’s, that prioritises player welfare and rest, while most unions already limit the number of minutes or matches their players can play.”

World Rugby’s chief medical officer Dr Eanna Falvey also said in a statement: “World Rugby welcomes the findings from the University of Glasgow and Professor Stewart’s call for further research into neurodegenerative disease in rugby.

“Innovation, that is led by science and research, is a central pillar of our six-point plan to make the sport we all care deeply about the most progressive in the world on player welfare.

“At World Rugby we have an independent concussion working group that considers all the latest academic research and findings.

“This enables us to have a constant and open conversation about what changes to the game may be appropriate and where further research may need to be focussed to help us drive forward our player welfare plan.

“World Rugby will never stand still on player welfare. To date, we have invested over 10million euros in welfare studies including the largest study into head impacts in community sport anywhere in the world and a study of health outcomes for over 3,000 retired rugby players, both delivered in partnership with New Zealand Rugby.

“We will continue to build on this work in our quest to make our game as safe as it can possibly be for players at all levels within the rugby family.”

The study, published in the Journal of Neurology Neurosurgery & Psychiatry, compared health outcomes among 412 male, Scottish, former international rugby players and over 1,200 matched individuals from the general population.

It was part-funded by the Football Association and Professional Footballers’ Association, building on the landmark 2019 study which found former professional footballers had an approximately three and a half times higher rate of death from neurodegenerative disease than expected.

Stewart said the numbers found had come as a “big surprise” and more work – including a broader study – was now needed to fully understand their meaning, although the immediate message for the game was clear.

Asked what steps should be taken within the game, he added: “Contact training during the week should be viewed as virtually a thing of the past, getting rid of as much as possible.

“Look at the number of matches being played and ask, ‘Is this credible that young men and women can be playing week-in, week-out, for the majority of the year just for entertainment?”

Progressive Rugby, a non-profit lobby group, called for the game’s authorities to heed the “further troubling evidence” of the study and “stop avoiding the inconvenient truth”.

Professor John Fairclough said: “Rugby remains a wonderful game but at the elite level it has become a contest featuring such brutal collisions that urgent changes, as outlined in Progressive Rugby’s 7-point plan published in August, are needed to better protect the short and long-term health of the players.

“Within that plan we highlight the importance of reducing exposure of players to contact training, restricting the number of games, and providing protected rest periods as well as implementing more cautious return-to-play protocols.

“If the governing bodies truly wish to secure the future of this great game for future generations it’s time for them to stop avoiding the inconvenient truth and act swiftly to demonstrate player welfare really is the game’s number one priority.”

The Rugby Players’ Association said in a statement: “The game has taken significant steps in the right direction, including World Rugby’s changes to the Graduated Return to Play, and the rollout of instrumented mouthguards across the men’s and women’s elite game in England, which we support and endorse.

“We still believe that swift action must be taken to reduce the level of exposure to both concussive and sub-concussive head impacts for our members, as total exposure over the course of a career is now as much a focus as standalone incidents.

“Increased understanding of this issue must shape the professional game’s position and approach to both training and match loads and limits, as well as all other welfare related topics, such as rest and season structure.”