This is the progression of world record improvements of the 400 metres M50 division of Masters athletics.
Key
HandAutoAthleteNationalityBirthdateLocationDateRef49.98Ricardo Roach Gonzalez12 October 1972Santiago19 October 202450.51Juan Lopez14 May 1970Granada16 July 202150.73Roland Gröger7 August 1964Berlin25 June 201751.39Fred Sowerby11 December 1948Orlando27 August 199951.60Guido Müller22 December 1938Hösbach3 June 198951.81Reginald Austin16 October 1936Melbourne4 December 198751.8Ron Taylor4 December 1933Swansea22 September 198652.24Ingo Vierk1935Rome29 June 198552.28Francis Peter Higgins16 November 1928Hannover1 August 197952.9Jack Greenwood5 February 1926Gothenburg8 August 1977
References
Masters Athletics 400 m list