Sports trainer and administrator. Born in Glasgow, Semple emigrated to the USA in 1921, where became a sports physiotherapist. In 1950, he became responsible for running the Boston Marathon, the world's oldest annual marathon event. Known for his short fuse, he took the event very seriously and railed against any who he regarded as frivolous competitors, gaining a reputation for physically attacking those he had taken a dislike to during the race. His most notorious attack was in 1967 against Katherine Switzer, the first woman to officially enter the race. He had not realised a female competitor had entered and was convinced this was inappropriate. He disgracefully set upon Switzer trying to pull her to the ground until Semple himself was brought down by Switzer's boyfriend and later husband, Tom Miller. Photographs of Semple's attack were spread across the media. Although Switzer successfully completed the race, Semple ensured she was disqualified. Following the race Semple remained furious and changed the rules to prevent the entry of women. He also lobbied the American Amateur Athletic Union to prevent women taking part in any competitions alongside male runners. Within five years, Semple had accepted that women could be serious athletes and he and Switzer were reconciled, becoming good friends. Semple himself had run more than a hundred marathons. He died in Massachusetts.