Bruce is considered to be one of the world’s greatest ultramarathon runners.
He ran his first Comrades Marathon in 1977 and has since won the Comrades eight times in succession, missing out 1989 to run the Standard Bank 100km Ultra. He returned to Comrades to win again in 1990. He ran the fastest Comrades Marathon in 1986 in a time of 5hrs 24, a record which stood for 21 years. He was the first runner to break 5 and half hours for the up run, and is the only runner who has broken the barrier 3 times.
He held the world record for 50 miles, which he set in 1983 while running the London to Brighton. The record stood for 35 years. He also holds the U.S. 50 mile All Comers record.