 Armstrong met Nigel Gates, a fellow athlete, in 1979 at an international race in Manresa, Spain, and they married in 1982.For the majority of Armstrong's international career they lived and worked together in Bath, having founded Springs Health Club in the city.They separated in 1993, and she has been married three times since then, competing as Julia McGowan (1994–1997) and Julia Cornford (1998–2001) before changing her name back to Armstrong.