John and his sister Sinead Kerr represented Great Britain at the Winter Olympics in 2006 and 2010 finishing in the top ten on both occasions.
In 2009 they won a bronze medal at the European Championships.
The Kerrs were due to retire after the 2010 season but decided to do one more season to make up for their Olympic disappointment. They gained another bronze medal at the 2011 European Championships performing.
At the end of their career they had won the British Championships a record seven consecutive times, between 2003 and 2009.