Ulster and Ireland prop Simon Best has announced his retirement from professional rugby on medical advice.

Best took the decision after undergoing a recent medical assessment that concluded he was at risk if he continued the intense training levels required for professional rugby.

The 30-year-old was found to have had an irregular heart rhythm after been taken ill at last year's World Cup, and while the tests didn't show any link between his rugby playing and his condition, he decided to put his health first.

"It is with great sadness that I am forced to retire from the game at this stage in my career," said Best.

"However, I have no regrets and feel immensely proud and privileged to have represented both Ulster and Ireland for the past nine years.

"I am grateful to have had the opportunity to work with coaches, management and players that I have had the utmost respect for and have formed lifelong friendships with many.

"I would like to thank the Ulster and Ireland supporters and my friends and family for their loyalty and support throughout my career and during this difficult time. I would also like to take this opportunity to thank the IRFU and their medical team for the extremely high standard of care that I have received.

"Finally, having grown up as a supporter of Ulster and Irish rugby I would like to wish the players and management of both squads all the very best for the rest of the season and the coming years, I will continue to support and follow their future successes with great interest."

Best was capped 25 times by Ireland and is the brother of fellow international player Rory.

Seán Fay / Eurosport