Career
Carroll missed the 1996 Olympics due to injury and missed qualifying for the 5,000m final at the 2000 Olympics by one place. He finished 6th in the 2002 New York Marathon, but decided not to look to compete over that distance in the 2004 Olympics due to the heat and humidity in Athens. He has also been coaching other Irish athletes such as Gareth Turnbull since about 2005 and in 2008 was appointed United States Athlete Manager for Athletics Ireland.
In August, 2009 he was appointed head cross country coach at Auburn University.
Personal bests 1500 metres - 3:34.91 minimum (2000).