He attended Llantarnam School, where he became a competitive swimmer, with aspirations of competing for Wales. He later studied for his undergraduate and Master of Business Administration degrees at the University of Wales Institute, Cardiff.
Born in Derbyshire, Hallam was raised in Cwmbran, South Wales. A motorcycle accident at age 17 (en route to a training session) resulted in his becoming a wheelchair user. After rehabilitation he spent some time living and traveling in South Africa, before returning to the United Kingdom and becoming involved in wheelchair sport.
In 2002 he became a Winston Churchill Fellow writing his report on the access of disabled people to specialist training equipment and gyms.
Although a successful kidney transplant in 1996 (with a living donation from his father), in latter years he experienced ill health. He was diagnosed with lymphoma in 2011 and received chemotherapy treatment.
During his career he held world records in the 100m and 200m. (1985: 21953, and 1987: 20834)
As an administrator he organised several National events, and was Chairman of the British Wheelchair Racing Association from 1990-1992.
He competed at four Paralympic Games. Stoke Mandeville, England (1984), Seoul, South of Korea (1988), Barcelona, Spain (1992) and Atlanta, United States (1996), as well as two Commonwealth Games. Auckland, New Zealand (1990) and Victoria, British Columbia (1994). In 1984 he won a gold medal for the 50m breast stroke, but it was on the track and road where he had the biggest impact. He won a bronze medal in the 400m in Seoul, and repeated this in the 100m in Barcelona. He won the London marathon twice, and broke the course record both times, in 1985 and 1987. He won the Great North Run on four occasions (1986, 1987, 1989 and 1990). He competed at two Commonwealth Games, in New Zealand (1990), and in Victoria, British Columbia (1994), respectively, as well as World and European Championships. In his coaching career he worked with several successful British athletes including Rose Hill, the British Record Holder for the marathon, and Dan Lucker who became world junior champion.
